New HPLC method was developed for determination of amlodipine and valsartan in their binary mixture as a part of routine control of combined formulations. The method was validated to meet official requirements includi...New HPLC method was developed for determination of amlodipine and valsartan in their binary mixture as a part of routine control of combined formulations. The method was validated to meet official requirements including selectivity, stability, linearity, precision and accuracy. Chromatography was carried out using a LiChrospher RP-18 column, a mixture containing acetonitrile, phosphate buffer of pH 3.5 and methanol (45:45:10, v/v/v) and new fluorescence detection at 255 nm for excitation and 448 nm for emission. The effect of methanol content, pH of the buffer, flow rate, detection wavelengths and column temperature was estimated in robustness study, according to a plan defined by the Plackett-Burman design. For identification of significant effects, both graphical and statistical methods were used. Ro-bustness for dissolution test was checked estimating the effects of paddle speed, temperature and pH of dissolution medium. The method was proved to complying with all official guidelines. Therefore, it is suitable for determination of amlodipine and valsartan in their binary mixtures for different analytical and pharmaceutical purposes.展开更多
High performance liquid chromatographic method was developed valdated and applied for the simultaneous determi- nation of lisinopril and NSAIDs in bulk, pharmaceuticals formulations and human serum. A Purospher star C...High performance liquid chromatographic method was developed valdated and applied for the simultaneous determi- nation of lisinopril and NSAIDs in bulk, pharmaceuticals formulations and human serum. A Purospher star C18 (5 μm, 25 × 0.46 cm) column was used with mobile phase consisting of methanol: water: acetonitrile (80:17.5:2.5 v/v, pH 3.0) and quantitative evaluation was performed at 225 nm with a flow rate of 1.0 mL?min–1. The retention time of lisinopril was 2.2 min while naproxen, flurbiprofen, diclofenac sodium and mefenamic acid were found to be 4.0, 4.5, 5.0 and 6.7 min respectively. Suitability of this method for the quantitative determination of the drugs was proved by validation in accordance with the requirements laid down by International Conference on Harmonization (ICH) guidelines. The method is selective, precise, accurate and can be used for analysis of pharmaceutical preparations in quality control and clinical laboratories.展开更多
A novel stability-indicating RP-HPLC method was developed and validated for simultaneous determination of Solifenacin Succinate & Tamsulosin Hydrochloride and its impurities in tablet dosage form. The method was d...A novel stability-indicating RP-HPLC method was developed and validated for simultaneous determination of Solifenacin Succinate & Tamsulosin Hydrochloride and its impurities in tablet dosage form. The method was developed using L1 column with gradient using the mobile phase consist of solvent-A (pH = 6.6, phosphate buffer + 0.5% Triethylamine) and solvent-B (90% Acetonitrile). The eluted compounds were monitored at 225 nm. Solifenacin Succinate & Tamsulosin Hydrochloride was subjected to oxidative, acid, base, hydrolytic, thermal and photolytic stress conditions. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantitation, accuracy, precision and robustness. The limit of quantification results was ranged from 0.135 - 0.221 μg/mL for Solifenacin Succinate impurities and 0.043 - 0.090 μg/mL for Tamsulosin Hydrochloride impurities. This method is suitable for the estimation of impurities and assay of Solifenacin Succinate & Tamsulosin Hydrochloride in tablets dosage form.展开更多
A simple efficient isocratic reversed-phase HPLC method was developed and validated for the determination of clindamycin palmitate hydrochloride (CPH) and its commercially available oral solution products. Separation ...A simple efficient isocratic reversed-phase HPLC method was developed and validated for the determination of clindamycin palmitate hydrochloride (CPH) and its commercially available oral solution products. Separation was achieved on a Phenomenex Zorbax (Luna) cyano column (150 × 4.6 mm, 5 μm) with a Phenomenex cyano guard cartridge (4 × 3.0 mm) on Agilent 1050 series HPLC system. CPH and its resolution standard lincomycin were eluted isocratically at a flow rate of 1 mL/min with a simplified mobile phase (potassium phosphate buffer (5 mM, pH 3.0)—acetonitrile—tetrahydrofuran (20:75:5, v/v/v)) and detected at 210 nm. The column was maintained at 25?C. The method was validated according to USP category I requirements. Robustness and forced degradation studies were also conducted. CPH marketed drug products were obtained from a drug distributor and assayed for potency using the validated method. Validation acceptance criteria were met in all cases. The analytical range for CPH was 15 - 500 μg/mL and the linearity was r2 > 0.999 over three days. The method was determined to be specific and robust. Both accuracy (92.0% - 103.8%) and precision (0.67% - 1.52%) were established across the analytical range for low, intermediate and high QC concentrations. Method applicability was demonstrated by analyzing two marketed products of CPH, in which results showed potency >98%. The method was determined to be an enhancement over the current USP methodology for assay as a result of increased efficiency, reduced organic solvents and the elimination of matrix modifiers. This method was successfully applied for the quality assessment of: 1) currently marketed drug products and 2) will in future assess the product quality of novel dosage forms of CPH for pediatric use.展开更多
A stability-indicating RP-HPLC method has been developed and validated for simultaneous determination of Valsartan & Hydrochlorothiazide and their impurities in FDC (Fixed Dose Combination) tablet dosage form. The...A stability-indicating RP-HPLC method has been developed and validated for simultaneous determination of Valsartan & Hydrochlorothiazide and their impurities in FDC (Fixed Dose Combination) tablet dosage form. The method was developed using L1 column (250 × 4.6 mm;5 μm) with gradient elution using the mobile phase consisting of solvent-A (0.1% Ortho phosphoric acid) and solvent-B (100% Acetonitrile);the gradient program (T<sub>min</sub>/%B) was set as 0/10, 5/10, 20/60, 40/60, 41/10 and 50/10. The eluted compounds were monitored at 265 nm. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantitation, accuracy, precision and robustness. The influence of Acid, Alkaline, Oxidative, Photolytic, Thermal and Humidity stress conditions, on drug product was studied. The limit of quantification results of Valsartan, Hydrochlorothiazide and their impurities are, VAL: 0.303 μg/mL, HCTZ: 0.019 μg/mL, VAL RC-B: 0.085 μg/mL, VAL RC-C: 0.327 μg/mL, HCT RC-A: 0.017 μg/mL, CTZ: 0.080 μg/mL and 5-Chloro HCT: 0.047 μg/mL. The proposed method is suitable for the estimation of Valsartan & Hydrochlorothiazide impurities in tablets dosage form.展开更多
The present data show a fast and efficient biological sample processing method for the extraction of thiamine (vitamin B1) and its mono-(TMP) and di-(TDP) phosphate esters from hippocampus, thalamus and prefrontal cor...The present data show a fast and efficient biological sample processing method for the extraction of thiamine (vitamin B1) and its mono-(TMP) and di-(TDP) phosphate esters from hippocampus, thalamus and prefrontal cortex (PFC) and blood sample of the rodents. In addition, using the hippocampus and standards of these three compounds we validated an isocratic fluorescence HPLC procedure for a simultaneous detection of them in a single chromatogram within a total run time of about 12 min. Reproducibility for TDP, TMP and B1 was 2.66%, 4.50% and 7.43% (intraday) and 37.54%, 25.39% and 25.87% (interday), respectively. Recovery assays were between 96.0% and 101.7%. The calibration curves were linear and the concentrations of the three compounds, all in nanomolar range, were determined in the brain areas and in the blood samples. When compared to the current methods in the literature, this new method provides information on essential variables, such as linearity range and limit of detection, reproducibility and stability of thiamine, TMP and TDP in rat brain samples. The present data on sample processing and B1 and its phosphate ester level determinations are the first to be validated using hippocampus samples of rats.展开更多
Saffron,the dried stigma of Crocus sativus L.,findsnumerous applications in TCM.Here,a novel HPLC protocol was established and applied for the analysis of saffron samples,not only from different places of origin but a...Saffron,the dried stigma of Crocus sativus L.,findsnumerous applications in TCM.Here,a novel HPLC protocol was established and applied for the analysis of saffron samples,not only from different places of origin but also from several harvest seasons.One of the main active constituents of saffron,crocin,is also contained in展开更多
A new method using high-performance liquid chromatography coupled with ultra violet detection(HPLC–UV)was developed and validated for the simultaneous quantification of atazanavir,dolutegravir,darunavir,efavirenz,etr...A new method using high-performance liquid chromatography coupled with ultra violet detection(HPLC–UV)was developed and validated for the simultaneous quantification of atazanavir,dolutegravir,darunavir,efavirenz,etravirine lopinavir,raltegravir,rilpivirine and tipranavir in human plasma.For the first time we reported here the development and validation of an HPLC–UV assay to quantify the frequently administered 9antiretroviral compounds including dolutegravir and rilpivirine.A simple solid phase extraction procedure was applied to 500 μL aliquots of plasma.The chromatographic separation of the drugs and internal standard(quinoxaline) was achieved with a gradient of acetonitrile and sodium acetate buffer on a C_(18) reverse-phase analytical column with a 25 min analytical run time.Calibration curves were optimised according to the therapeutic range of drug concentrations in patients,and the coefficient of determination(r^2) was higher than0.99 for all analytes.Mean intraday and interday precisions(RSD) for all compounds were less than 15.0%,and the mean accuracy(% deviation from nominal concentration) was also found to be less than 15.0%.Extraction recovery range was between 80% and 120% for all drugs analysed.The solid phase extraction and HPLC–UV method enable a specific,sensitive,and reliable simultaneous determination of nine antiretroviral agents in plasma.Good extraction efficiency and low limit of HPLC–UV quantification make this method suitable for use in clinical trials and therapeutic drug monitoring.展开更多
In this study, we reported and validated a novel and sensitive reversed-phase liquid chromatographic method for the simultaneous determination of irbesartan, candesartan, gliquidone and pioglitazone. Separation was pe...In this study, we reported and validated a novel and sensitive reversed-phase liquid chromatographic method for the simultaneous determination of irbesartan, candesartan, gliquidone and pioglitazone. Separation was performed at 230 nm using a mobile phase consisting of methanol–water(90:10, v/v) with a flow rate of 1 mL/min. p H was adjusted to 3.5 with phosphoric acid. The concentration-response relationship was found linear over a concentration range of 5–25 μg/mL for all of the analytes tested. The limits of detection and quantification were 0.83 and 2.78 for irbesartan, 0.30 and 1.01 for candesartan, 1.11 and 3.93 for gliquidone, and 0.41 and 1.41 μg/mL for pioglitazone, respectively. Described method permitted the successful determination of these drugs in human serum. The developed method was simple, rapid, and it did not require extensive sample purification.展开更多
An assay is presented for simultaneously determining 5 biogenic amines and the major non-protein amino acids: the toxin β-N-oxalyl-L-α,β-diaminopropanoic acid (β-ODAP), its isomer α-ODAP and homoarginine in Lathy...An assay is presented for simultaneously determining 5 biogenic amines and the major non-protein amino acids: the toxin β-N-oxalyl-L-α,β-diaminopropanoic acid (β-ODAP), its isomer α-ODAP and homoarginine in Lathyrus sativus extracts using the HPLC system after derivatization with para-nitrobenzyloxycarbonyl chloride (PNZ-Cl). However, it is more worthy of noting that this paper also describes a new extraction method using 0.2 mol/L HClO4. The new method has some advantages: shorter extraction-time, simultaneous extraction of free amino acids and polyamines, better inhibiting the isomerization of β-ODAP to α-ODAP, and so on.展开更多
In the present study, comprehensive stress testing of tenatoprazole was carried out according to ICH guide-line Q1A (R2). Tenatoprazole was subjected to stress conditions of hydrolysis, oxidation, photolysis and neutr...In the present study, comprehensive stress testing of tenatoprazole was carried out according to ICH guide-line Q1A (R2). Tenatoprazole was subjected to stress conditions of hydrolysis, oxidation, photolysis and neutral decomposition. Extensive degradation was found to occur in acidic, neutral and oxidative conditions. Mild degradation was observed in basic conditions. The drug is relatively stable in the solid-state. Successful separation of drug from degradation products formed under stress conditions was achieved on a Kromasil C18 column (250 mm × 4.6 mm, 5.0 μ particle size) using methanol: THF: acetate buffer (68:12:20 v/v) pH adjusted to 6.0 with acetic acid as mobile phase, flow rate was 1.0 mL●min–1 and column was maintained at 45°C. Quantification and linearity was achieved at 307 nm over the concentration range of 0.5 - 160 μg●mL–1 for tenatoprazole. The method was validated for specificity, linearity, accuracy, precision, LOD, LOQ and robustness.展开更多
文摘New HPLC method was developed for determination of amlodipine and valsartan in their binary mixture as a part of routine control of combined formulations. The method was validated to meet official requirements including selectivity, stability, linearity, precision and accuracy. Chromatography was carried out using a LiChrospher RP-18 column, a mixture containing acetonitrile, phosphate buffer of pH 3.5 and methanol (45:45:10, v/v/v) and new fluorescence detection at 255 nm for excitation and 448 nm for emission. The effect of methanol content, pH of the buffer, flow rate, detection wavelengths and column temperature was estimated in robustness study, according to a plan defined by the Plackett-Burman design. For identification of significant effects, both graphical and statistical methods were used. Ro-bustness for dissolution test was checked estimating the effects of paddle speed, temperature and pH of dissolution medium. The method was proved to complying with all official guidelines. Therefore, it is suitable for determination of amlodipine and valsartan in their binary mixtures for different analytical and pharmaceutical purposes.
文摘High performance liquid chromatographic method was developed valdated and applied for the simultaneous determi- nation of lisinopril and NSAIDs in bulk, pharmaceuticals formulations and human serum. A Purospher star C18 (5 μm, 25 × 0.46 cm) column was used with mobile phase consisting of methanol: water: acetonitrile (80:17.5:2.5 v/v, pH 3.0) and quantitative evaluation was performed at 225 nm with a flow rate of 1.0 mL?min–1. The retention time of lisinopril was 2.2 min while naproxen, flurbiprofen, diclofenac sodium and mefenamic acid were found to be 4.0, 4.5, 5.0 and 6.7 min respectively. Suitability of this method for the quantitative determination of the drugs was proved by validation in accordance with the requirements laid down by International Conference on Harmonization (ICH) guidelines. The method is selective, precise, accurate and can be used for analysis of pharmaceutical preparations in quality control and clinical laboratories.
文摘A novel stability-indicating RP-HPLC method was developed and validated for simultaneous determination of Solifenacin Succinate & Tamsulosin Hydrochloride and its impurities in tablet dosage form. The method was developed using L1 column with gradient using the mobile phase consist of solvent-A (pH = 6.6, phosphate buffer + 0.5% Triethylamine) and solvent-B (90% Acetonitrile). The eluted compounds were monitored at 225 nm. Solifenacin Succinate & Tamsulosin Hydrochloride was subjected to oxidative, acid, base, hydrolytic, thermal and photolytic stress conditions. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantitation, accuracy, precision and robustness. The limit of quantification results was ranged from 0.135 - 0.221 μg/mL for Solifenacin Succinate impurities and 0.043 - 0.090 μg/mL for Tamsulosin Hydrochloride impurities. This method is suitable for the estimation of impurities and assay of Solifenacin Succinate & Tamsulosin Hydrochloride in tablets dosage form.
文摘A simple efficient isocratic reversed-phase HPLC method was developed and validated for the determination of clindamycin palmitate hydrochloride (CPH) and its commercially available oral solution products. Separation was achieved on a Phenomenex Zorbax (Luna) cyano column (150 × 4.6 mm, 5 μm) with a Phenomenex cyano guard cartridge (4 × 3.0 mm) on Agilent 1050 series HPLC system. CPH and its resolution standard lincomycin were eluted isocratically at a flow rate of 1 mL/min with a simplified mobile phase (potassium phosphate buffer (5 mM, pH 3.0)—acetonitrile—tetrahydrofuran (20:75:5, v/v/v)) and detected at 210 nm. The column was maintained at 25?C. The method was validated according to USP category I requirements. Robustness and forced degradation studies were also conducted. CPH marketed drug products were obtained from a drug distributor and assayed for potency using the validated method. Validation acceptance criteria were met in all cases. The analytical range for CPH was 15 - 500 μg/mL and the linearity was r2 > 0.999 over three days. The method was determined to be specific and robust. Both accuracy (92.0% - 103.8%) and precision (0.67% - 1.52%) were established across the analytical range for low, intermediate and high QC concentrations. Method applicability was demonstrated by analyzing two marketed products of CPH, in which results showed potency >98%. The method was determined to be an enhancement over the current USP methodology for assay as a result of increased efficiency, reduced organic solvents and the elimination of matrix modifiers. This method was successfully applied for the quality assessment of: 1) currently marketed drug products and 2) will in future assess the product quality of novel dosage forms of CPH for pediatric use.
文摘A stability-indicating RP-HPLC method has been developed and validated for simultaneous determination of Valsartan & Hydrochlorothiazide and their impurities in FDC (Fixed Dose Combination) tablet dosage form. The method was developed using L1 column (250 × 4.6 mm;5 μm) with gradient elution using the mobile phase consisting of solvent-A (0.1% Ortho phosphoric acid) and solvent-B (100% Acetonitrile);the gradient program (T<sub>min</sub>/%B) was set as 0/10, 5/10, 20/60, 40/60, 41/10 and 50/10. The eluted compounds were monitored at 265 nm. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantitation, accuracy, precision and robustness. The influence of Acid, Alkaline, Oxidative, Photolytic, Thermal and Humidity stress conditions, on drug product was studied. The limit of quantification results of Valsartan, Hydrochlorothiazide and their impurities are, VAL: 0.303 μg/mL, HCTZ: 0.019 μg/mL, VAL RC-B: 0.085 μg/mL, VAL RC-C: 0.327 μg/mL, HCT RC-A: 0.017 μg/mL, CTZ: 0.080 μg/mL and 5-Chloro HCT: 0.047 μg/mL. The proposed method is suitable for the estimation of Valsartan & Hydrochlorothiazide impurities in tablets dosage form.
文摘The present data show a fast and efficient biological sample processing method for the extraction of thiamine (vitamin B1) and its mono-(TMP) and di-(TDP) phosphate esters from hippocampus, thalamus and prefrontal cortex (PFC) and blood sample of the rodents. In addition, using the hippocampus and standards of these three compounds we validated an isocratic fluorescence HPLC procedure for a simultaneous detection of them in a single chromatogram within a total run time of about 12 min. Reproducibility for TDP, TMP and B1 was 2.66%, 4.50% and 7.43% (intraday) and 37.54%, 25.39% and 25.87% (interday), respectively. Recovery assays were between 96.0% and 101.7%. The calibration curves were linear and the concentrations of the three compounds, all in nanomolar range, were determined in the brain areas and in the blood samples. When compared to the current methods in the literature, this new method provides information on essential variables, such as linearity range and limit of detection, reproducibility and stability of thiamine, TMP and TDP in rat brain samples. The present data on sample processing and B1 and its phosphate ester level determinations are the first to be validated using hippocampus samples of rats.
文摘Saffron,the dried stigma of Crocus sativus L.,findsnumerous applications in TCM.Here,a novel HPLC protocol was established and applied for the analysis of saffron samples,not only from different places of origin but also from several harvest seasons.One of the main active constituents of saffron,crocin,is also contained in
基金supported by “Ministero della Salute” “Ricerca corrente 2015” grant to E.C.
文摘A new method using high-performance liquid chromatography coupled with ultra violet detection(HPLC–UV)was developed and validated for the simultaneous quantification of atazanavir,dolutegravir,darunavir,efavirenz,etravirine lopinavir,raltegravir,rilpivirine and tipranavir in human plasma.For the first time we reported here the development and validation of an HPLC–UV assay to quantify the frequently administered 9antiretroviral compounds including dolutegravir and rilpivirine.A simple solid phase extraction procedure was applied to 500 μL aliquots of plasma.The chromatographic separation of the drugs and internal standard(quinoxaline) was achieved with a gradient of acetonitrile and sodium acetate buffer on a C_(18) reverse-phase analytical column with a 25 min analytical run time.Calibration curves were optimised according to the therapeutic range of drug concentrations in patients,and the coefficient of determination(r^2) was higher than0.99 for all analytes.Mean intraday and interday precisions(RSD) for all compounds were less than 15.0%,and the mean accuracy(% deviation from nominal concentration) was also found to be less than 15.0%.Extraction recovery range was between 80% and 120% for all drugs analysed.The solid phase extraction and HPLC–UV method enable a specific,sensitive,and reliable simultaneous determination of nine antiretroviral agents in plasma.Good extraction efficiency and low limit of HPLC–UV quantification make this method suitable for use in clinical trials and therapeutic drug monitoring.
文摘In this study, we reported and validated a novel and sensitive reversed-phase liquid chromatographic method for the simultaneous determination of irbesartan, candesartan, gliquidone and pioglitazone. Separation was performed at 230 nm using a mobile phase consisting of methanol–water(90:10, v/v) with a flow rate of 1 mL/min. p H was adjusted to 3.5 with phosphoric acid. The concentration-response relationship was found linear over a concentration range of 5–25 μg/mL for all of the analytes tested. The limits of detection and quantification were 0.83 and 2.78 for irbesartan, 0.30 and 1.01 for candesartan, 1.11 and 3.93 for gliquidone, and 0.41 and 1.41 μg/mL for pioglitazone, respectively. Described method permitted the successful determination of these drugs in human serum. The developed method was simple, rapid, and it did not require extensive sample purification.
基金This work was supported by NKBRSF Project(G2000018603)the National Natural Science Foundation of China(No.30270965).
文摘An assay is presented for simultaneously determining 5 biogenic amines and the major non-protein amino acids: the toxin β-N-oxalyl-L-α,β-diaminopropanoic acid (β-ODAP), its isomer α-ODAP and homoarginine in Lathyrus sativus extracts using the HPLC system after derivatization with para-nitrobenzyloxycarbonyl chloride (PNZ-Cl). However, it is more worthy of noting that this paper also describes a new extraction method using 0.2 mol/L HClO4. The new method has some advantages: shorter extraction-time, simultaneous extraction of free amino acids and polyamines, better inhibiting the isomerization of β-ODAP to α-ODAP, and so on.
文摘In the present study, comprehensive stress testing of tenatoprazole was carried out according to ICH guide-line Q1A (R2). Tenatoprazole was subjected to stress conditions of hydrolysis, oxidation, photolysis and neutral decomposition. Extensive degradation was found to occur in acidic, neutral and oxidative conditions. Mild degradation was observed in basic conditions. The drug is relatively stable in the solid-state. Successful separation of drug from degradation products formed under stress conditions was achieved on a Kromasil C18 column (250 mm × 4.6 mm, 5.0 μ particle size) using methanol: THF: acetate buffer (68:12:20 v/v) pH adjusted to 6.0 with acetic acid as mobile phase, flow rate was 1.0 mL●min–1 and column was maintained at 45°C. Quantification and linearity was achieved at 307 nm over the concentration range of 0.5 - 160 μg●mL–1 for tenatoprazole. The method was validated for specificity, linearity, accuracy, precision, LOD, LOQ and robustness.
