Detecting faces under occlusion remains a significant challenge in computer vision due to variations caused by masks,sunglasses,and other obstructions.Addressing this issue is crucial for applications such as surveill...Detecting faces under occlusion remains a significant challenge in computer vision due to variations caused by masks,sunglasses,and other obstructions.Addressing this issue is crucial for applications such as surveillance,biometric authentication,and human-computer interaction.This paper provides a comprehensive review of face detection techniques developed to handle occluded faces.Studies are categorized into four main approaches:feature-based,machine learning-based,deep learning-based,and hybrid methods.We analyzed state-of-the-art studies within each category,examining their methodologies,strengths,and limitations based on widely used benchmark datasets,highlighting their adaptability to partial and severe occlusions.The review also identifies key challenges,including dataset diversity,model generalization,and computational efficiency.Our findings reveal that deep learning methods dominate recent studies,benefiting from their ability to extract hierarchical features and handle complex occlusion patterns.More recently,researchers have increasingly explored Transformer-based architectures,such as Vision Transformer(ViT)and Swin Transformer,to further improve detection robustness under challenging occlusion scenarios.In addition,hybrid approaches,which aim to combine traditional andmodern techniques,are emerging as a promising direction for improving robustness.This review provides valuable insights for researchers aiming to develop more robust face detection systems and for practitioners seeking to deploy reliable solutions in real-world,occlusionprone environments.Further improvements and the proposal of broader datasets are required to developmore scalable,robust,and efficient models that can handle complex occlusions in real-world scenarios.展开更多
Face detection is a critical component inmodern security,surveillance,and human-computer interaction systems,with widespread applications in smartphones,biometric access control,and public monitoring.However,detecting...Face detection is a critical component inmodern security,surveillance,and human-computer interaction systems,with widespread applications in smartphones,biometric access control,and public monitoring.However,detecting faces with high levels of occlusion,such as those covered by masks,veils,or scarves,remains a significant challenge,as traditional models often fail to generalize under such conditions.This paper presents a hybrid approach that combines traditional handcrafted feature extraction technique called Histogram of Oriented Gradients(HOG)and Canny edge detection with modern deep learning models.The goal is to improve face detection accuracy under occlusions.The proposed method leverages the structural strengths of HOG and edge-based object proposals while exploiting the feature extraction capabilities of Convolutional Neural Networks(CNNs).The effectiveness of the proposed model is assessed using a custom dataset containing 10,000 heavily occluded face images and a subset of the Common Objects in Context(COCO)dataset for non-face samples.The COCO dataset was selected for its variety and realism in background contexts.Experimental evaluations demonstrate significant performance improvements compared to baseline CNN models.Results indicate that DenseNet121 combined with HOG outperforms other counterparts in classification metrics with an F1-score of 87.96%and precision of 88.02%.Enhanced performance is achieved through reduced false positives and improved localization accuracy with the integration of object proposals based on Canny and contour detection.While the proposed method increases inference time from 33.52 to 97.80 ms,it achieves a notable improvement in precision from 80.85% to 88.02% when comparing the baseline DenseNet121 model to its hybrid counterpart.Limitations of the method include higher computational cost and the need for careful tuning of parameters across the edge detection,handcrafted features,and CNN components.These findings highlight the potential of combining handcrafted and learned features for occluded face detection tasks.展开更多
Scientific evidence sustains PM_(2.5)particles’inhalation may generate harmful impacts on human beings’health;therefore,theirmonitoring in ambient air is of paramount relevance in terms of public health.Due to the l...Scientific evidence sustains PM_(2.5)particles’inhalation may generate harmful impacts on human beings’health;therefore,theirmonitoring in ambient air is of paramount relevance in terms of public health.Due to the limited number of fixed stations within the air qualitymonitoring networks,development ofmethodological frameworks tomodel ambient air PM_(2.5)particles is primordial to providing additional information on PM_(2.5)exposure and its trends.In this sense,this work aims to offer a global easily-applicable tool to estimate ambient air PM_(2.5)as a function of meteorological conditions using a multivariate analysis.Daily PM_(2.5)data measured by 84 fixed monitoring stations and meteorological data from ERA5(ECMWF Reanalysis v5)reanalysis daily based data between 2000 and 2021 across the United Kingdom were attended to develop the suggested approach.Data from January 2017 to December 2020 were employed to build amathematical expression that related the dependent variable(PM_(2.5))to predictor ones(sea-level pressure,planetary boundary layer height,temperature,precipitation,wind direction and speed),while 2021 data tested the model.Evaluation indicators evidenced a good performance of model(maximum values of RMSE,MAE and MAPE:1.80μg/m^(3),3.24μg/m^(3),and 20.63%,respectively),compiling the current legislation’s requirements for modelling ambient air PM_(2.5)concentrations.A retrospective analysis of meteorological features allowed estimating ambient air PM_(2.5)concentrations from 2000 to 2021.The highest PM_(2.5)concentrations relapsed in theMid-and Southlands,while Northlands sustained the lowest concentrations.展开更多
A simple, sensitive and precise green high-performance liquid chromatographic method including on-line pre-column oxidation combined by column switching with a short Hypersil ODS analytical column (100 mm × 4.0 m...A simple, sensitive and precise green high-performance liquid chromatographic method including on-line pre-column oxidation combined by column switching with a short Hypersil ODS analytical column (100 mm × 4.0 mm i.d.) for enrichment and separation was developed and validated to determine low levels of methotrexate (MTX). The method was based on oxidative cleavage of MTX into highly fluorescence products, 2,4-diaminopteridine-6-carboxaldehyde and the corresponding 2,4-diaminopteridine-6-carboxylic acid, during the flow of phosphate buffer (0.04 M, pH 3.4) containing the analyte through the packed reactor of cerium (IV) trihydroxyhydroperoxide (CTH) at a flow-rate of 0.2 mL/min and 40℃. The fluorescent products were enriched on the head of ODS analytical column for the final separation. The separation was performed at room temperature using an environmentally friendly mobile phase consisting of ethanol and phosphate buffer (0.04 M, pH 3.4) in the ratio of 10:90 (v/v). The eluent was monitored at emission and excitation wavelengths of 463 and 367 nm, respectively. The method was successfully applied, without any interference from the excipients, for the determination of drug in tablets and vials with a detection limit of 0.06 ng/mL from 500 ?L of sample MTX.展开更多
Research into long-chain polyunsaturated fatty acids (LC-PUFA), such as docosahexaenoic acid (DHA C22:6 n-3), has shown that their inclusion in the human diet is linked with many health benefits. This has led to an in...Research into long-chain polyunsaturated fatty acids (LC-PUFA), such as docosahexaenoic acid (DHA C22:6 n-3), has shown that their inclusion in the human diet is linked with many health benefits. This has led to an increased interest in the enrichment of certain foodstuffs with DHA by supplementing animal fed with DHA-rich ingredients which can lead to an increased uptake in the meat, milk and eggs animal by-products. The microalgae Aurantiochytrium limacinum has been found to be especially useful in this pursuit. It is subsequently desirable to availably have a simple and robust method for the routine analysis of DHA and other fatty acids in the algal biomass. The AOAC method 996.06 is often followed for the analysis of fatty acids in foods and demonstrating that its fitness for purpose in the analysis of DHA and additional fatty acids in Aurantiochytrium limacinum is therefore the objective of this paper. A validation of the method for the determination of DHA and three other fatty acids in Aurantiochytrium limacinum is presented. The method was found to be linear over the following ranges for each fatty acid methyl ester (FAME) analyte;50 to 15,000 μg/ml (C14:0), 300 to 95,000 (C16:0), 25 to 15,000 (C18:0) and 300 to 59,375 (C22:6). The accuracy, precision and LOD and LOQ of the method were confirmed and its robustness tested. The application of the method to assess the stability of Aurantiochytrium limacinum containing two alternative antioxidants was further examined. The investigation showed that DHA was stable over six months with the inclusion of either Duralox? or ethoxyquin as an antioxidant and ethoxyquin could additionally stabilize DHA in Aurantiochytrium limacinum up to 24 months.展开更多
Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic me...Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic method using High Resolution Mass Spectrometer (LC-HRMS) technique is proved to be suitable for simultaneous quantification of all ten identified impurities with required specificity, sensitivity, resolution, precision, accuracy, and other method characteristics as per ICH Guidelines. The acceptable limit of less than 2.9 μg/g was considered for evaluations, based on drug substance dosage and duration of treatment. The method stands most sensitive with a Limit of Detection of 0.35 μg/g, considering the challenge full acceptance criteria as per current regulatory standards.展开更多
Three sensitive,selective and reproducible stability-indicating methods are presented for determination of nitazoxanide (NTZ),a new anti-protozoal drug,in presence of its degradation products.Method A utilizes the fir...Three sensitive,selective and reproducible stability-indicating methods are presented for determination of nitazoxanide (NTZ),a new anti-protozoal drug,in presence of its degradation products.Method A utilizes the first derivative of ratio spectra spectrophotometry by measurement of the amplitude at 364.4 nm using one of the degradation products as a divisor.Method B is a chemometric-assisted spectrophotometry,where principal component regression (PCR) and partial least squares (PLS) were applied.These two approaches were successfully applied to quantify NTZ in presence of degradation products using the information included in the absorption spectra in the range 260-360 nm.Method C is based on the separation of NTZ from its degradation products followed by densitometric measurement of the bands at 254 nm.The separation was carried out on silica gel 60F 254,using chloroform-methanol-ammonia solution-glacial acetic acid (95:5:1:1 by volume,pH=5.80) as a developing system.These methods are suitable as stability-indicating methods for the determination of NTZ in presence of its degradation products either in bulk powder or in pharmaceutical formulations.Statistical analysis of the results has been carried out revealing high accuracy and good precision.展开更多
BACKGROUND MMP-2 also known as gelatinase A and MMP-7(matrilysin)are members of the zinc-dependent family of MMPs(Matrix metalloproteinase).MMP-2 and MMP-7 are remodeling enzymes that digest extracellular matrix;MMP-2...BACKGROUND MMP-2 also known as gelatinase A and MMP-7(matrilysin)are members of the zinc-dependent family of MMPs(Matrix metalloproteinase).MMP-2 and MMP-7 are remodeling enzymes that digest extracellular matrix;MMP-2 is extensively expressed during development and is upregulated at sites of tissue damage,inflammation,and in stromal cells of metastatic tumors.MMP-7 is expressed in the epithelial cells and in a variety of cancers including colon tumors.Plasma MMP-2 and MMP-7 levels were assessed before and after minimally invasive colorectal resection for cancer pathology.AIM To determine plasma MMP-2 and MMP-7 levels before and after minimally invasive colorectal resection for cancer pathology.METHODS Patients enrolled in a plasma bank for whom plasma was available were eligible.Plasma obtained from preoperative(Preop)and postoperative blood samples was used.Only colorectal cancer(CRC)patients who underwent elective minimally invasive cancer resection with preop,post-operative day(POD)1,3 and at least 1 late postop sample(POD 7-34)were included.Late samples were bundled into 7 d blocks(POD 7-13,14-20,etc.)and treated as single time points.Plasma MMP-2 and MMP-7 levels were determined via enzyme-linked immunosorbent assay in duplicate.RESULTS Total 88 minimally invasive CRC resection CRC patients were studied(right colectomy,37%;sigmoid,24%;and LAR/AR 18%).Cancer stages were:1,31%;2,30%;3,34%;and 4,5%.Mean Preop MMP-2 plasma level(ng/mL)was 179.3±40.9(n=88).Elevated mean levels were noted on POD1(214.3±51.2,n=87,P<0.001),POD3(258.0±63.9,n=80,P<0.001),POD7-13(229.9±62.3,n=65,P<0.001),POD 14-20(234.9±47.5,n=25,P<0.001),POD 21-27(237.0±63.5,n=17,P<0.001,)and POD 28-34(255.4±59.7,n=15,P<0.001).Mean Preop MMP-7 level was 3.9±1.9(n=88).No significant differences were noted on POD 1 or 3,however,significantly elevated levels were noted on POD 7-13(5.7±2.5,n=65,P<0.001),POD 14-20(5.9±2.5,n=25,P<0.001),POD 21-27(6.1±3.6,n=17,P=0.002)and on POD 28-34(6.8±3.3,n=15 P<0.001,)vs preop levels.CONCLUSION MMP-2 levels are elevated for 5 wk and MMP-7 levels elevated for weeks 2-6.The etiology of these changes in unclear,trauma and wound healing likely play a role.These changes may promote residual tumor growth and metastasis.展开更多
This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle （AV） technologies. AV technologies can decrease the transporta...This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle （AV） technologies. AV technologies can decrease the transportation cost and increase accessibility to low-income households and persons with mobility issues. This emerging technology also has far-reaching applications and implications beyond all current expectations. This paper provides a comprehensive review of the relevant literature and explores a broad spectrum of issues from safety to machine ethics. An indispensable part of a prospective AV development is communication over cars and infrastructure （connected vehicles）. A major knowledge gap exists in AV technology with respect to routing behaviors. Connected- vehicle technology provides a great opportunity to imple- ment an efficient and intelligent routing system. To this end, we propose a conceptual navigation model based on a fleet of AVs that are centrally dispatched over a network seeking system optimization literature on two fronts： （i） This study contributes to the it attempts to shed light on future opportunities as well as possible hurdles associated with AV technology; and （ii） it conceptualizes a navigation model for the AV which leads to highly efficient traffic circulations.展开更多
Phytoremediation is a promising approach for reclamation of salt-affected soil.Phytoextraction is the most commonly used process,which exploits plants to absorb,immobilize,and accumulate salt in their shoots.In this s...Phytoremediation is a promising approach for reclamation of salt-affected soil.Phytoextraction is the most commonly used process,which exploits plants to absorb,immobilize,and accumulate salt in their shoots.In this study,halotolerant plant growth-promoting rhizobacteria(PGPR)were isolated from the rhizosphere of wild grasses growing naturally in salt-affected areas of Lucknow,Uttar Pradesh(India)and were tested for their efficacies of salt-tolerance and plant growth-promoting(PGP)abilities.Based on 16S rRNA sequences,the most efficient halotolerant isolates possessing PGP traits were identified as Pseudomonas plecoglossicida(KM 233646),Acinetobacter calcoaceticus(KM 233647),Bacillus flexus(KM 233648),and Bacillus safensis(KM 233652).Application of these isolates as bio-inoculants significantly(P<0.05)increased the growth and bacoside A yield of a medicinal plant,Bacopa monnieri(L.)Nash,grown on natural salt-affected soil.The phytoremediation of salt-affected soil was evident by the substantial increase in shoot Na^+:K^+ratio of bio-inoculant-treated plants.When compared to un-inoculated control plants,the soil physico-chemical properties of bio-inoculant-treated plants were improved.The shoot and root biomass(fresh and dry weights),soil enzymes,and soil nutrient parameters showed significant positive correlations with the shoot Na+:K+ratio.Consequently,the halotolerant PGPR screened in this study could be useful for the reclamation of saline soils concomitant with improved plant growth and bacoside A yield.展开更多
Three simple,specific,accurate and precise spectrophotometric methods are developed for simultaneous determination of amlodipine besylate(AM)and atenolol(AT)in tablets.The first method is dual wavelength spectrophotom...Three simple,specific,accurate and precise spectrophotometric methods are developed for simultaneous determination of amlodipine besylate(AM)and atenolol(AT)in tablets.The first method is dual wavelength spectrophotometry(DW).The second method is ratio subtraction(RS)which depends on subtraction of the plateau values from the ratio spectrum,coupled to first derivative of ratio spectra(1 DD).The third method applies bivariate calibration method using 210and 225nm as an optimum pair of wavelength for amlodipine and atenolol.The calibration curves are linear over the concentration range of 4~40μg·mL-1 for both drugs.The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures of the two drugs and their combined dosage form.The two methods are validated as per ICH guidelines and can be applied for routine quality control testing.展开更多
A simple, sensitive, and specific method was developed for simultaneous determination of Amlodipine besylate (AML), Valsartan (Vals) and Hydrochlorothiazide (HCT) by high performance liquid chromatography without prev...A simple, sensitive, and specific method was developed for simultaneous determination of Amlodipine besylate (AML), Valsartan (Vals) and Hydrochlorothiazide (HCT) by high performance liquid chromatography without previous separation. Satisfactory resolution was achieved using a RP-C18 chromatographic column, Phenomenex Kinetex (150 mm × 4.6 mm i.d) and a mobile phase consisting of acetonitrile-phosphate buffer (0.05 M) with pH 2.8 in the proportion of (40/60, v/v) at a flow rate 0.8 mL/min and the wavelength detection was 227 nm. The retention time for HCT, AML and VAls was 2.26, 3.16 and 11.19 min;respectively. The described method was linear over a range of 4-28 μg /ml, 5-40 μg /ml and 1-12 μg /ml for AML, Vals and HCT;respectively. The mean percent recoveries were 99.94%, 99.96% and 99.78% for AML, Vals and HCT;respectively. F-test and t-test at 95%con?dence level were used to check the intermediate precision data obtained under different experimental setups. The method could be used for analysis of combined dose tablet formulation containing AML, Vals, HCT as well as spiked human plasma.展开更多
Tadalafil(TAD)and dapoxetine HCl(DAP)are recently co-formulated and both show native fluorescence.Therefore,a novel,accurate,specific and sensitive reversed-phase high performance liquid chromatographic method with fl...Tadalafil(TAD)and dapoxetine HCl(DAP)are recently co-formulated and both show native fluorescence.Therefore,a novel,accurate,specific and sensitive reversed-phase high performance liquid chromatographic method with fluorescence detection was developed and validated for their separation and quantitation in dosage form and human plasma using avanafil as an internal standard(IS).Separation was achieved using isocratic elution within 7.0 min on C18column and acetonitrile-0.15%triethylamine(40∶60,v/v;pH 4)as a mobile phase.The flow rate was 1.0 mL/min and the detection was time-programmed at 330,410 and 370 nm for TAD,DAP and IS,respectively,after excitation at 236 nm.The linear ranges from 0.01 to 30.00μg/mL for each drug with the limits of detection of 4.20 and 7.20 ng/mL for TAD and DAP,respectively.The method was validated in accordance to the International Conference on Harmonization(ICH)guidelines and was successfully applied to spiked human plasma with mean recoveries of 98.17%and 98.83%for TAD and DAP respectively.展开更多
A new simple spectrophotometric method was developed for the simultaneous determination of drugs with interfering spectra in binary mixtures without previous separation. The new method is based on a simple modificatio...A new simple spectrophotometric method was developed for the simultaneous determination of drugs with interfering spectra in binary mixtures without previous separation. The new method is based on a simple modification for the ratio subtraction method. This modification enabled wider range of application. The proposed ratio difference method was applied for the determination of brimonidine and timolol in laboratory prepared mixtures with mean percentage recoveries 100.40±2.29 and 101.23± 1.30 respectively, and in their pharmaceutical formulation with mean percentage recoveries 101.08±0.44 and 100.66±0.52 respectively. The suggested ratio difference method was validated according to USP guidelines and can be applied for routine aualitv control testing.展开更多
Air pollution causes deleterious effects on human health with aerosols being among the most polluting agents.The objective of this work is the characterization of the PM2.5 and PM10 aerosol mass in the atmosphere.The ...Air pollution causes deleterious effects on human health with aerosols being among the most polluting agents.The objective of this work is the characterization of the PM2.5 and PM10 aerosol mass in the atmosphere.The methods of analysis include WD-XRF and EDS.Data were correlated with meteorological information and air mass trajectories(model HYSPLIT)by multivariate analysis.A morphological structural analysis was also carried out to identify the probable sources of atmospheric aerosols in the city of Sao Jose do Rio Preto,Brazil.The mean mass concentration values obtained were 24.54 μg/m^3 for PM10,above the WHO annual standard value of 20 μg/m^3 and 10.88 μg/m^3 for PM2.5 whose WHO recommended limit is10 μg/m^3.WD-XRF analysis of the samples revealed Si and Al as major components of the coarse fraction.In the fine fraction,the major elements were Al and S.The SEM-FEG characterization allowed identifying the morphology of the particles in agglomerates,ellipsoids and filaments in the PM10,besides spherical in the PM2.5.The analysis by EDS corroborated WD-XRF results,identifying the crustal elements,aluminosilicates and elements of anthropogenic origin in the coarse fraction.For the fine fraction crustal elements were also identified;aluminosilicates,black carbon and spherical particles(C and O) originating from combustion processes were predominant.The use of multivariate analysis to correlate air mass trajectories with the results of the morpho-structural characterization of the particulate matter allowed confirmation of the complex composition of the particles resulting from the combination of both local and long-distance sources.展开更多
Gas stations are important emissions source of benzene (C6H6), toluene (C7H8), ethylbenzene (C8H10), and ortho, meta and para-xylene (C8H10)—better known by the acronym BTEX. The objective of this study was to determ...Gas stations are important emissions source of benzene (C6H6), toluene (C7H8), ethylbenzene (C8H10), and ortho, meta and para-xylene (C8H10)—better known by the acronym BTEX. The objective of this study was to determine the concentrations of BTEX compounds in the ambient air of ten gas stations in the cities of Salvador and Feira de Santana, Bahia, Brazil and evaluate the health risks to workers. Passive samplers diffusive of the Radiello?, containing activated carbon as adsorbent, were used. The samplers were exposed for 8 h and then the analytes were recovered by chemical desorption with CS2 and determined by GC-FID. The BTEX concentrations found in the ambient air of gas stations ranged from 46.72 - 435.43 μg·m?3 for benzene;25.54 - 342.46 μg·m?3 for toluene, 7.10 - 30.07 μg·m?3 for ethylbenzene, 9.36 - 89.73 μg·m?3 for m, p-xylene and 9.79 - 52.29 μg·m?3 for o-xylene. The concentrations of toluene, ethylbenzene and xylenes found in gas stations were lower than the limits recommended by the US NIOSH and NR-15 of the Ministry of Labour of Brazil;however, it should be considered the risks due to chronic exposure of workers. Benzene concentrations in three gas stations were above the exposure limit recommended by NIOSH (3.20 × 102 μg·m?3). Samplings were also held outdoors at 250 m of two gas stations. The total concentrations of the BTEX compounds were equal to 24.97 and 35.51 μg·m?3, and benzene concentrations were about 3 - 4 times higher than the annual pattern of 5.0 μg·m?3 established by Union European, as tolerance limit for outside areas. These data confirm that the next areas of gas stations are subject to the effects of volatilization of these compounds. Additionally, the values found in the 10 gas stations for the cancer risk ranged from 4.06 × 10?5 - 3.78 × 10?4 (mean of 1.82 × 10?4) for workers exposed to benzene for 30 years (acceptable limit equal 1.00 × 10?6). The cancer risk is very high, because the values found are about 40 - 378 times above the acceptable limit and reinforce the need to adopt urgent measures to reduce or eliminate exposure of workers to the BTEX compounds. The average non-cancer risk to benzene, toluene, ethylbenzene and xylenes was 1.84, 5.76 × 10?3, 4.59 × 10?3 and 1.37 × 10?1, respectively (acceptable limit 1). Only to benzene the average value of this risk is above 1, showing that workers are likely the adverse effects health due to exposure to benzene.展开更多
A new impurity was detected during high performance liquid chromatographic （HPLC） analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liqui...A new impurity was detected during high performance liquid chromatographic （HPLC） analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liquid chromatography mass spectrometry using electrospray ionization and ion trap analyzer （LC/ESI-IT/MS） analysis. Proposed structure of impurity was unambiguously confirmed by synthesis followed by characterization using 1H, 13C nuclear magnetic resonance spectrometry （NMR）, 1H-1H correlation spectro-scopy （COSY） and infrared spectroscopy （IR）. Based on the spectroscopic and spectrometric data, unknown impurity was characterized as 5-carbamoyl-10,11-dihydro-5H-dibenzo[b,f]azepin-10-yl propionate.展开更多
A stability indicating LC method was developed for the simultaneous determination of Amlodipine and Benazepril capsules in pharmaceutical dosage form. Efficient chromatographic separation was achieved on Symmetry C18 ...A stability indicating LC method was developed for the simultaneous determination of Amlodipine and Benazepril capsules in pharmaceutical dosage form. Efficient chromatographic separation was achieved on Symmetry C18 stationary phase with simple combination of amobile phase containing 750 mL of DI Water, 250 mL of Acetonitrile and 2 mL of Octylamine into suitable container with adjusted pH to 2.50 ± 0.05 with the aid of Ortho phosphoric acid delivered in an isocratic mode and quantification was carried out using UV detection at 240 nm at a flow rate of 1.0 mL·min-1 with an injection volume of 20 μl and ambient column temperature. This method is capable to detect both the drug components of Amlodipine and Benazepril in presence of their degradation products (Amlodipine Imp-A and Benazepril Impurity-C) with a detection level of 0.05%. Amlodipine/Benazepril in their combination drug product were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions, and the samples were analysed. Peak homogeneity data of Amlodipine and Benazeprilis were obtained using PDA detector, in the stressed sample chromatograms, demonstrating the specificity. The method shows excellent linearity over a range of 0.05%-2.0% for Amlodipine, Amlodipine Impurity-A and 0.05%-5.0% for Benazepril and Benazepril Impurity-C. The correlation coefficient for Amlodipine and Benazepril is 1. The relative standard deviation was always less than 2%. The proposed method was found to be suitable and accurate for quantitative determination and the stability study of Amlodipine and Benazepril in pharmaceutical preparations. The developed HPLC method was validated with respect to linearity & range, accuracy, precision and robustness.展开更多
基金funded by A’Sharqiyah University,Sultanate of Oman,under Research Project grant number(BFP/RGP/ICT/22/490).
文摘Detecting faces under occlusion remains a significant challenge in computer vision due to variations caused by masks,sunglasses,and other obstructions.Addressing this issue is crucial for applications such as surveillance,biometric authentication,and human-computer interaction.This paper provides a comprehensive review of face detection techniques developed to handle occluded faces.Studies are categorized into four main approaches:feature-based,machine learning-based,deep learning-based,and hybrid methods.We analyzed state-of-the-art studies within each category,examining their methodologies,strengths,and limitations based on widely used benchmark datasets,highlighting their adaptability to partial and severe occlusions.The review also identifies key challenges,including dataset diversity,model generalization,and computational efficiency.Our findings reveal that deep learning methods dominate recent studies,benefiting from their ability to extract hierarchical features and handle complex occlusion patterns.More recently,researchers have increasingly explored Transformer-based architectures,such as Vision Transformer(ViT)and Swin Transformer,to further improve detection robustness under challenging occlusion scenarios.In addition,hybrid approaches,which aim to combine traditional andmodern techniques,are emerging as a promising direction for improving robustness.This review provides valuable insights for researchers aiming to develop more robust face detection systems and for practitioners seeking to deploy reliable solutions in real-world,occlusionprone environments.Further improvements and the proposal of broader datasets are required to developmore scalable,robust,and efficient models that can handle complex occlusions in real-world scenarios.
基金funded by A’Sharqiyah University,Sultanate of Oman,under Research Project Grant Number(BFP/RGP/ICT/22/490).
文摘Face detection is a critical component inmodern security,surveillance,and human-computer interaction systems,with widespread applications in smartphones,biometric access control,and public monitoring.However,detecting faces with high levels of occlusion,such as those covered by masks,veils,or scarves,remains a significant challenge,as traditional models often fail to generalize under such conditions.This paper presents a hybrid approach that combines traditional handcrafted feature extraction technique called Histogram of Oriented Gradients(HOG)and Canny edge detection with modern deep learning models.The goal is to improve face detection accuracy under occlusions.The proposed method leverages the structural strengths of HOG and edge-based object proposals while exploiting the feature extraction capabilities of Convolutional Neural Networks(CNNs).The effectiveness of the proposed model is assessed using a custom dataset containing 10,000 heavily occluded face images and a subset of the Common Objects in Context(COCO)dataset for non-face samples.The COCO dataset was selected for its variety and realism in background contexts.Experimental evaluations demonstrate significant performance improvements compared to baseline CNN models.Results indicate that DenseNet121 combined with HOG outperforms other counterparts in classification metrics with an F1-score of 87.96%and precision of 88.02%.Enhanced performance is achieved through reduced false positives and improved localization accuracy with the integration of object proposals based on Canny and contour detection.While the proposed method increases inference time from 33.52 to 97.80 ms,it achieves a notable improvement in precision from 80.85% to 88.02% when comparing the baseline DenseNet121 model to its hybrid counterpart.Limitations of the method include higher computational cost and the need for careful tuning of parameters across the edge detection,handcrafted features,and CNN components.These findings highlight the potential of combining handcrafted and learned features for occluded face detection tasks.
基金supported by the Collaborative Research Project(CRP)grant,Nazarbayev University(Nos.11022021CRP1512,211123CRP1604)PK acknowledges the support from the NERC-funded projects ASAP-Delhi(NE/P016510/1),GreenCities(NE/P016510/1)RECLAIM Network Plus(EP/W034034/1).
文摘Scientific evidence sustains PM_(2.5)particles’inhalation may generate harmful impacts on human beings’health;therefore,theirmonitoring in ambient air is of paramount relevance in terms of public health.Due to the limited number of fixed stations within the air qualitymonitoring networks,development ofmethodological frameworks tomodel ambient air PM_(2.5)particles is primordial to providing additional information on PM_(2.5)exposure and its trends.In this sense,this work aims to offer a global easily-applicable tool to estimate ambient air PM_(2.5)as a function of meteorological conditions using a multivariate analysis.Daily PM_(2.5)data measured by 84 fixed monitoring stations and meteorological data from ERA5(ECMWF Reanalysis v5)reanalysis daily based data between 2000 and 2021 across the United Kingdom were attended to develop the suggested approach.Data from January 2017 to December 2020 were employed to build amathematical expression that related the dependent variable(PM_(2.5))to predictor ones(sea-level pressure,planetary boundary layer height,temperature,precipitation,wind direction and speed),while 2021 data tested the model.Evaluation indicators evidenced a good performance of model(maximum values of RMSE,MAE and MAPE:1.80μg/m^(3),3.24μg/m^(3),and 20.63%,respectively),compiling the current legislation’s requirements for modelling ambient air PM_(2.5)concentrations.A retrospective analysis of meteorological features allowed estimating ambient air PM_(2.5)concentrations from 2000 to 2021.The highest PM_(2.5)concentrations relapsed in theMid-and Southlands,while Northlands sustained the lowest concentrations.
文摘A simple, sensitive and precise green high-performance liquid chromatographic method including on-line pre-column oxidation combined by column switching with a short Hypersil ODS analytical column (100 mm × 4.0 mm i.d.) for enrichment and separation was developed and validated to determine low levels of methotrexate (MTX). The method was based on oxidative cleavage of MTX into highly fluorescence products, 2,4-diaminopteridine-6-carboxaldehyde and the corresponding 2,4-diaminopteridine-6-carboxylic acid, during the flow of phosphate buffer (0.04 M, pH 3.4) containing the analyte through the packed reactor of cerium (IV) trihydroxyhydroperoxide (CTH) at a flow-rate of 0.2 mL/min and 40℃. The fluorescent products were enriched on the head of ODS analytical column for the final separation. The separation was performed at room temperature using an environmentally friendly mobile phase consisting of ethanol and phosphate buffer (0.04 M, pH 3.4) in the ratio of 10:90 (v/v). The eluent was monitored at emission and excitation wavelengths of 463 and 367 nm, respectively. The method was successfully applied, without any interference from the excipients, for the determination of drug in tablets and vials with a detection limit of 0.06 ng/mL from 500 ?L of sample MTX.
文摘Research into long-chain polyunsaturated fatty acids (LC-PUFA), such as docosahexaenoic acid (DHA C22:6 n-3), has shown that their inclusion in the human diet is linked with many health benefits. This has led to an increased interest in the enrichment of certain foodstuffs with DHA by supplementing animal fed with DHA-rich ingredients which can lead to an increased uptake in the meat, milk and eggs animal by-products. The microalgae Aurantiochytrium limacinum has been found to be especially useful in this pursuit. It is subsequently desirable to availably have a simple and robust method for the routine analysis of DHA and other fatty acids in the algal biomass. The AOAC method 996.06 is often followed for the analysis of fatty acids in foods and demonstrating that its fitness for purpose in the analysis of DHA and additional fatty acids in Aurantiochytrium limacinum is therefore the objective of this paper. A validation of the method for the determination of DHA and three other fatty acids in Aurantiochytrium limacinum is presented. The method was found to be linear over the following ranges for each fatty acid methyl ester (FAME) analyte;50 to 15,000 μg/ml (C14:0), 300 to 95,000 (C16:0), 25 to 15,000 (C18:0) and 300 to 59,375 (C22:6). The accuracy, precision and LOD and LOQ of the method were confirmed and its robustness tested. The application of the method to assess the stability of Aurantiochytrium limacinum containing two alternative antioxidants was further examined. The investigation showed that DHA was stable over six months with the inclusion of either Duralox? or ethoxyquin as an antioxidant and ethoxyquin could additionally stabilize DHA in Aurantiochytrium limacinum up to 24 months.
文摘Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic method using High Resolution Mass Spectrometer (LC-HRMS) technique is proved to be suitable for simultaneous quantification of all ten identified impurities with required specificity, sensitivity, resolution, precision, accuracy, and other method characteristics as per ICH Guidelines. The acceptable limit of less than 2.9 μg/g was considered for evaluations, based on drug substance dosage and duration of treatment. The method stands most sensitive with a Limit of Detection of 0.35 μg/g, considering the challenge full acceptance criteria as per current regulatory standards.
文摘Three sensitive,selective and reproducible stability-indicating methods are presented for determination of nitazoxanide (NTZ),a new anti-protozoal drug,in presence of its degradation products.Method A utilizes the first derivative of ratio spectra spectrophotometry by measurement of the amplitude at 364.4 nm using one of the degradation products as a divisor.Method B is a chemometric-assisted spectrophotometry,where principal component regression (PCR) and partial least squares (PLS) were applied.These two approaches were successfully applied to quantify NTZ in presence of degradation products using the information included in the absorption spectra in the range 260-360 nm.Method C is based on the separation of NTZ from its degradation products followed by densitometric measurement of the bands at 254 nm.The separation was carried out on silica gel 60F 254,using chloroform-methanol-ammonia solution-glacial acetic acid (95:5:1:1 by volume,pH=5.80) as a developing system.These methods are suitable as stability-indicating methods for the determination of NTZ in presence of its degradation products either in bulk powder or in pharmaceutical formulations.Statistical analysis of the results has been carried out revealing high accuracy and good precision.
文摘BACKGROUND MMP-2 also known as gelatinase A and MMP-7(matrilysin)are members of the zinc-dependent family of MMPs(Matrix metalloproteinase).MMP-2 and MMP-7 are remodeling enzymes that digest extracellular matrix;MMP-2 is extensively expressed during development and is upregulated at sites of tissue damage,inflammation,and in stromal cells of metastatic tumors.MMP-7 is expressed in the epithelial cells and in a variety of cancers including colon tumors.Plasma MMP-2 and MMP-7 levels were assessed before and after minimally invasive colorectal resection for cancer pathology.AIM To determine plasma MMP-2 and MMP-7 levels before and after minimally invasive colorectal resection for cancer pathology.METHODS Patients enrolled in a plasma bank for whom plasma was available were eligible.Plasma obtained from preoperative(Preop)and postoperative blood samples was used.Only colorectal cancer(CRC)patients who underwent elective minimally invasive cancer resection with preop,post-operative day(POD)1,3 and at least 1 late postop sample(POD 7-34)were included.Late samples were bundled into 7 d blocks(POD 7-13,14-20,etc.)and treated as single time points.Plasma MMP-2 and MMP-7 levels were determined via enzyme-linked immunosorbent assay in duplicate.RESULTS Total 88 minimally invasive CRC resection CRC patients were studied(right colectomy,37%;sigmoid,24%;and LAR/AR 18%).Cancer stages were:1,31%;2,30%;3,34%;and 4,5%.Mean Preop MMP-2 plasma level(ng/mL)was 179.3±40.9(n=88).Elevated mean levels were noted on POD1(214.3±51.2,n=87,P<0.001),POD3(258.0±63.9,n=80,P<0.001),POD7-13(229.9±62.3,n=65,P<0.001),POD 14-20(234.9±47.5,n=25,P<0.001),POD 21-27(237.0±63.5,n=17,P<0.001,)and POD 28-34(255.4±59.7,n=15,P<0.001).Mean Preop MMP-7 level was 3.9±1.9(n=88).No significant differences were noted on POD 1 or 3,however,significantly elevated levels were noted on POD 7-13(5.7±2.5,n=65,P<0.001),POD 14-20(5.9±2.5,n=25,P<0.001),POD 21-27(6.1±3.6,n=17,P=0.002)and on POD 28-34(6.8±3.3,n=15 P<0.001,)vs preop levels.CONCLUSION MMP-2 levels are elevated for 5 wk and MMP-7 levels elevated for weeks 2-6.The etiology of these changes in unclear,trauma and wound healing likely play a role.These changes may promote residual tumor growth and metastasis.
文摘This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle （AV） technologies. AV technologies can decrease the transportation cost and increase accessibility to low-income households and persons with mobility issues. This emerging technology also has far-reaching applications and implications beyond all current expectations. This paper provides a comprehensive review of the relevant literature and explores a broad spectrum of issues from safety to machine ethics. An indispensable part of a prospective AV development is communication over cars and infrastructure （connected vehicles）. A major knowledge gap exists in AV technology with respect to routing behaviors. Connected- vehicle technology provides a great opportunity to imple- ment an efficient and intelligent routing system. To this end, we propose a conceptual navigation model based on a fleet of AVs that are centrally dispatched over a network seeking system optimization literature on two fronts： （i） This study contributes to the it attempts to shed light on future opportunities as well as possible hurdles associated with AV technology; and （ii） it conceptualizes a navigation model for the AV which leads to highly efficient traffic circulations.
文摘Phytoremediation is a promising approach for reclamation of salt-affected soil.Phytoextraction is the most commonly used process,which exploits plants to absorb,immobilize,and accumulate salt in their shoots.In this study,halotolerant plant growth-promoting rhizobacteria(PGPR)were isolated from the rhizosphere of wild grasses growing naturally in salt-affected areas of Lucknow,Uttar Pradesh(India)and were tested for their efficacies of salt-tolerance and plant growth-promoting(PGP)abilities.Based on 16S rRNA sequences,the most efficient halotolerant isolates possessing PGP traits were identified as Pseudomonas plecoglossicida(KM 233646),Acinetobacter calcoaceticus(KM 233647),Bacillus flexus(KM 233648),and Bacillus safensis(KM 233652).Application of these isolates as bio-inoculants significantly(P<0.05)increased the growth and bacoside A yield of a medicinal plant,Bacopa monnieri(L.)Nash,grown on natural salt-affected soil.The phytoremediation of salt-affected soil was evident by the substantial increase in shoot Na^+:K^+ratio of bio-inoculant-treated plants.When compared to un-inoculated control plants,the soil physico-chemical properties of bio-inoculant-treated plants were improved.The shoot and root biomass(fresh and dry weights),soil enzymes,and soil nutrient parameters showed significant positive correlations with the shoot Na+:K+ratio.Consequently,the halotolerant PGPR screened in this study could be useful for the reclamation of saline soils concomitant with improved plant growth and bacoside A yield.
文摘Three simple,specific,accurate and precise spectrophotometric methods are developed for simultaneous determination of amlodipine besylate(AM)and atenolol(AT)in tablets.The first method is dual wavelength spectrophotometry(DW).The second method is ratio subtraction(RS)which depends on subtraction of the plateau values from the ratio spectrum,coupled to first derivative of ratio spectra(1 DD).The third method applies bivariate calibration method using 210and 225nm as an optimum pair of wavelength for amlodipine and atenolol.The calibration curves are linear over the concentration range of 4~40μg·mL-1 for both drugs.The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures of the two drugs and their combined dosage form.The two methods are validated as per ICH guidelines and can be applied for routine quality control testing.
文摘A simple, sensitive, and specific method was developed for simultaneous determination of Amlodipine besylate (AML), Valsartan (Vals) and Hydrochlorothiazide (HCT) by high performance liquid chromatography without previous separation. Satisfactory resolution was achieved using a RP-C18 chromatographic column, Phenomenex Kinetex (150 mm × 4.6 mm i.d) and a mobile phase consisting of acetonitrile-phosphate buffer (0.05 M) with pH 2.8 in the proportion of (40/60, v/v) at a flow rate 0.8 mL/min and the wavelength detection was 227 nm. The retention time for HCT, AML and VAls was 2.26, 3.16 and 11.19 min;respectively. The described method was linear over a range of 4-28 μg /ml, 5-40 μg /ml and 1-12 μg /ml for AML, Vals and HCT;respectively. The mean percent recoveries were 99.94%, 99.96% and 99.78% for AML, Vals and HCT;respectively. F-test and t-test at 95%con?dence level were used to check the intermediate precision data obtained under different experimental setups. The method could be used for analysis of combined dose tablet formulation containing AML, Vals, HCT as well as spiked human plasma.
文摘Tadalafil(TAD)and dapoxetine HCl(DAP)are recently co-formulated and both show native fluorescence.Therefore,a novel,accurate,specific and sensitive reversed-phase high performance liquid chromatographic method with fluorescence detection was developed and validated for their separation and quantitation in dosage form and human plasma using avanafil as an internal standard(IS).Separation was achieved using isocratic elution within 7.0 min on C18column and acetonitrile-0.15%triethylamine(40∶60,v/v;pH 4)as a mobile phase.The flow rate was 1.0 mL/min and the detection was time-programmed at 330,410 and 370 nm for TAD,DAP and IS,respectively,after excitation at 236 nm.The linear ranges from 0.01 to 30.00μg/mL for each drug with the limits of detection of 4.20 and 7.20 ng/mL for TAD and DAP,respectively.The method was validated in accordance to the International Conference on Harmonization(ICH)guidelines and was successfully applied to spiked human plasma with mean recoveries of 98.17%and 98.83%for TAD and DAP respectively.
文摘A new simple spectrophotometric method was developed for the simultaneous determination of drugs with interfering spectra in binary mixtures without previous separation. The new method is based on a simple modification for the ratio subtraction method. This modification enabled wider range of application. The proposed ratio difference method was applied for the determination of brimonidine and timolol in laboratory prepared mixtures with mean percentage recoveries 100.40±2.29 and 101.23± 1.30 respectively, and in their pharmaceutical formulation with mean percentage recoveries 101.08±0.44 and 100.66±0.52 respectively. The suggested ratio difference method was validated according to USP guidelines and can be applied for routine aualitv control testing.
基金supported by CAPES (scholarship),PROPGUNESP Foundation (Brazil) and Portuguese Foundation for Science and Technology (FCT) through the project UID/QUI/ 00100/2019.
文摘Air pollution causes deleterious effects on human health with aerosols being among the most polluting agents.The objective of this work is the characterization of the PM2.5 and PM10 aerosol mass in the atmosphere.The methods of analysis include WD-XRF and EDS.Data were correlated with meteorological information and air mass trajectories(model HYSPLIT)by multivariate analysis.A morphological structural analysis was also carried out to identify the probable sources of atmospheric aerosols in the city of Sao Jose do Rio Preto,Brazil.The mean mass concentration values obtained were 24.54 μg/m^3 for PM10,above the WHO annual standard value of 20 μg/m^3 and 10.88 μg/m^3 for PM2.5 whose WHO recommended limit is10 μg/m^3.WD-XRF analysis of the samples revealed Si and Al as major components of the coarse fraction.In the fine fraction,the major elements were Al and S.The SEM-FEG characterization allowed identifying the morphology of the particles in agglomerates,ellipsoids and filaments in the PM10,besides spherical in the PM2.5.The analysis by EDS corroborated WD-XRF results,identifying the crustal elements,aluminosilicates and elements of anthropogenic origin in the coarse fraction.For the fine fraction crustal elements were also identified;aluminosilicates,black carbon and spherical particles(C and O) originating from combustion processes were predominant.The use of multivariate analysis to correlate air mass trajectories with the results of the morpho-structural characterization of the particulate matter allowed confirmation of the complex composition of the particles resulting from the combination of both local and long-distance sources.
文摘Gas stations are important emissions source of benzene (C6H6), toluene (C7H8), ethylbenzene (C8H10), and ortho, meta and para-xylene (C8H10)—better known by the acronym BTEX. The objective of this study was to determine the concentrations of BTEX compounds in the ambient air of ten gas stations in the cities of Salvador and Feira de Santana, Bahia, Brazil and evaluate the health risks to workers. Passive samplers diffusive of the Radiello?, containing activated carbon as adsorbent, were used. The samplers were exposed for 8 h and then the analytes were recovered by chemical desorption with CS2 and determined by GC-FID. The BTEX concentrations found in the ambient air of gas stations ranged from 46.72 - 435.43 μg·m?3 for benzene;25.54 - 342.46 μg·m?3 for toluene, 7.10 - 30.07 μg·m?3 for ethylbenzene, 9.36 - 89.73 μg·m?3 for m, p-xylene and 9.79 - 52.29 μg·m?3 for o-xylene. The concentrations of toluene, ethylbenzene and xylenes found in gas stations were lower than the limits recommended by the US NIOSH and NR-15 of the Ministry of Labour of Brazil;however, it should be considered the risks due to chronic exposure of workers. Benzene concentrations in three gas stations were above the exposure limit recommended by NIOSH (3.20 × 102 μg·m?3). Samplings were also held outdoors at 250 m of two gas stations. The total concentrations of the BTEX compounds were equal to 24.97 and 35.51 μg·m?3, and benzene concentrations were about 3 - 4 times higher than the annual pattern of 5.0 μg·m?3 established by Union European, as tolerance limit for outside areas. These data confirm that the next areas of gas stations are subject to the effects of volatilization of these compounds. Additionally, the values found in the 10 gas stations for the cancer risk ranged from 4.06 × 10?5 - 3.78 × 10?4 (mean of 1.82 × 10?4) for workers exposed to benzene for 30 years (acceptable limit equal 1.00 × 10?6). The cancer risk is very high, because the values found are about 40 - 378 times above the acceptable limit and reinforce the need to adopt urgent measures to reduce or eliminate exposure of workers to the BTEX compounds. The average non-cancer risk to benzene, toluene, ethylbenzene and xylenes was 1.84, 5.76 × 10?3, 4.59 × 10?3 and 1.37 × 10?1, respectively (acceptable limit 1). Only to benzene the average value of this risk is above 1, showing that workers are likely the adverse effects health due to exposure to benzene.
文摘A new impurity was detected during high performance liquid chromatographic （HPLC） analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liquid chromatography mass spectrometry using electrospray ionization and ion trap analyzer （LC/ESI-IT/MS） analysis. Proposed structure of impurity was unambiguously confirmed by synthesis followed by characterization using 1H, 13C nuclear magnetic resonance spectrometry （NMR）, 1H-1H correlation spectro-scopy （COSY） and infrared spectroscopy （IR）. Based on the spectroscopic and spectrometric data, unknown impurity was characterized as 5-carbamoyl-10,11-dihydro-5H-dibenzo[b,f]azepin-10-yl propionate.
文摘A stability indicating LC method was developed for the simultaneous determination of Amlodipine and Benazepril capsules in pharmaceutical dosage form. Efficient chromatographic separation was achieved on Symmetry C18 stationary phase with simple combination of amobile phase containing 750 mL of DI Water, 250 mL of Acetonitrile and 2 mL of Octylamine into suitable container with adjusted pH to 2.50 ± 0.05 with the aid of Ortho phosphoric acid delivered in an isocratic mode and quantification was carried out using UV detection at 240 nm at a flow rate of 1.0 mL·min-1 with an injection volume of 20 μl and ambient column temperature. This method is capable to detect both the drug components of Amlodipine and Benazepril in presence of their degradation products (Amlodipine Imp-A and Benazepril Impurity-C) with a detection level of 0.05%. Amlodipine/Benazepril in their combination drug product were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions, and the samples were analysed. Peak homogeneity data of Amlodipine and Benazeprilis were obtained using PDA detector, in the stressed sample chromatograms, demonstrating the specificity. The method shows excellent linearity over a range of 0.05%-2.0% for Amlodipine, Amlodipine Impurity-A and 0.05%-5.0% for Benazepril and Benazepril Impurity-C. The correlation coefficient for Amlodipine and Benazepril is 1. The relative standard deviation was always less than 2%. The proposed method was found to be suitable and accurate for quantitative determination and the stability study of Amlodipine and Benazepril in pharmaceutical preparations. The developed HPLC method was validated with respect to linearity & range, accuracy, precision and robustness.
