An accurate, simple and sensitive high performance liquid chromarographic (HPLC) method for simultaneous determination of ticlopidine hydrochloride and nitrendipine in a new tablet formulation is described. Chromatogr...An accurate, simple and sensitive high performance liquid chromarographic (HPLC) method for simultaneous determination of ticlopidine hydrochloride and nitrendipine in a new tablet formulation is described. Chromatographic separation of ticlopidine hydrochloride and nitrendipine was achieved on a Hypersil BDS C18 column using a mobile phase consisting of acetonitrile-methanol-10 mmol/L ammonium acetate (60∶10∶30(V/V), pH 6.5) at a flow rate of 1.0 mL/min. Absorbance was monitored at 236 nm where both drugs have significant absorption. The proposed method was validated with respect to linearity, selectivity, accuracy, precision, and limits of detection and quantitation. The linear ranges for ticlopidine hydrochloride and nitrendipine were found to be 75-750 μg/mL and 1-10 μg/mL, respectively. The mean recoveries were 100.1%(S R=0.6%,n=9) for ticlopidine hydrochloride and 99.9%(S R=0.7%,n=9) for nitrendipine. The within-day precision and between-day precision for ticlopidine hydrochloride and nitrendipine were 0.63% and 0.89%, and 0.74% and 1.0%, respectively. The proposed HPLC method can be used for the simultaneous determination of both drugs in pharmaceutical preparations.展开更多
To compare pharmacokinetic behaviors of nitrendipine submicron emulsion with nitrendipine solution following intravenous administration in rats.The plasma concentrations were analyzed by ultra-performance liquid chrom...To compare pharmacokinetic behaviors of nitrendipine submicron emulsion with nitrendipine solution following intravenous administration in rats.The plasma concentrations were analyzed by ultra-performance liquid chromatography coupled with tandem mass spectrometry detection(UPLC-MS/MS)through a new validated method.The pharmacokinetic parameters of the nitrendipine submicron emulsion and nitrendipine solution were as follows:AUC_(0-t) 900.76±186.59 versus 687.08±66.24 ng h/ml,C_(max) 854.54±159.48 versus 610.59±235.99 ng/ml,t_(1/2)2.37±1.99 versus 2.80±2.69 h.The relative bioavailability of nitrendipine submicron emulsion to nitrendipine solution was 131.4±11.3%.The developed methods could meet the requirements of bioanalysis.Compared to the solution injection,intravenous submicron emulsion presents higher systematic exposure which can help to improve the therapeutic efficacy.展开更多
In a multicenter, randomized single blind and parallel study, 488 patients with essential hypertension received 4 weeks treatment with amlodipine or nitrendipine. The response rate of amlodipine is 90.4%, higher than ...In a multicenter, randomized single blind and parallel study, 488 patients with essential hypertension received 4 weeks treatment with amlodipine or nitrendipine. The response rate of amlodipine is 90.4%, higher than that of nitrendipine, and the adverse reactions were less than those of nitrendipine. Hence amlodipine is a safe and effective antihypertensive agent. Its once-daily dose (5-10mg) makes it very convenient for clinical use.展开更多
The enantiomers separation of ei ght pharmaceutical racemates collected in Chinese Pharmacopoeia 2010(Ch.P2010),including nitrendipine,felodipine,omeprazole,praziquantel,sulpiride,clenbuterol hydrochloride,verapamil h...The enantiomers separation of ei ght pharmaceutical racemates collected in Chinese Pharmacopoeia 2010(Ch.P2010),including nitrendipine,felodipine,omeprazole,praziquantel,sulpiride,clenbuterol hydrochloride,verapamil hydrochloride and chlorphenamine maleate,was performed on chiral stationary phase of amylose ramification by high performance liquid chromatography(HPLC)on Chiralpak AD-H column and Chiralpak AS-H column with the mobile phase consisted of isopropanol and n-hexane.The detection wavelength and the flow rate were set at 254 nm and 0.7 mL/min,respectively.The effects of proportion of organic additives,alcohol displacer and temperature on the separation were investigated.The results indicated that eight chiral drugs were separated on chiral stationary phase of amylase ramification in normal phase chroma tographic system.The chromatographic retention and resolution of enantiomers were adjusted by factors,including the changes of the concentration of alcohol displacer in mobile phase,organic alkaline modifier and column temperature.It was shown that the resolution was improved with reducing concentration of alcohol displacer.When the concentration of organic alkaline modifier was 0.2%,the resolution and the peak shape were fairly good.Most racemates mentioned above had the best resolution at column temperature of 25℃.The best temperature should be kept unchanged in the process of separation so as to obtain stable separation results.展开更多
文摘An accurate, simple and sensitive high performance liquid chromarographic (HPLC) method for simultaneous determination of ticlopidine hydrochloride and nitrendipine in a new tablet formulation is described. Chromatographic separation of ticlopidine hydrochloride and nitrendipine was achieved on a Hypersil BDS C18 column using a mobile phase consisting of acetonitrile-methanol-10 mmol/L ammonium acetate (60∶10∶30(V/V), pH 6.5) at a flow rate of 1.0 mL/min. Absorbance was monitored at 236 nm where both drugs have significant absorption. The proposed method was validated with respect to linearity, selectivity, accuracy, precision, and limits of detection and quantitation. The linear ranges for ticlopidine hydrochloride and nitrendipine were found to be 75-750 μg/mL and 1-10 μg/mL, respectively. The mean recoveries were 100.1%(S R=0.6%,n=9) for ticlopidine hydrochloride and 99.9%(S R=0.7%,n=9) for nitrendipine. The within-day precision and between-day precision for ticlopidine hydrochloride and nitrendipine were 0.63% and 0.89%, and 0.74% and 1.0%, respectively. The proposed HPLC method can be used for the simultaneous determination of both drugs in pharmaceutical preparations.
文摘To compare pharmacokinetic behaviors of nitrendipine submicron emulsion with nitrendipine solution following intravenous administration in rats.The plasma concentrations were analyzed by ultra-performance liquid chromatography coupled with tandem mass spectrometry detection(UPLC-MS/MS)through a new validated method.The pharmacokinetic parameters of the nitrendipine submicron emulsion and nitrendipine solution were as follows:AUC_(0-t) 900.76±186.59 versus 687.08±66.24 ng h/ml,C_(max) 854.54±159.48 versus 610.59±235.99 ng/ml,t_(1/2)2.37±1.99 versus 2.80±2.69 h.The relative bioavailability of nitrendipine submicron emulsion to nitrendipine solution was 131.4±11.3%.The developed methods could meet the requirements of bioanalysis.Compared to the solution injection,intravenous submicron emulsion presents higher systematic exposure which can help to improve the therapeutic efficacy.
文摘In a multicenter, randomized single blind and parallel study, 488 patients with essential hypertension received 4 weeks treatment with amlodipine or nitrendipine. The response rate of amlodipine is 90.4%, higher than that of nitrendipine, and the adverse reactions were less than those of nitrendipine. Hence amlodipine is a safe and effective antihypertensive agent. Its once-daily dose (5-10mg) makes it very convenient for clinical use.
文摘The enantiomers separation of ei ght pharmaceutical racemates collected in Chinese Pharmacopoeia 2010(Ch.P2010),including nitrendipine,felodipine,omeprazole,praziquantel,sulpiride,clenbuterol hydrochloride,verapamil hydrochloride and chlorphenamine maleate,was performed on chiral stationary phase of amylose ramification by high performance liquid chromatography(HPLC)on Chiralpak AD-H column and Chiralpak AS-H column with the mobile phase consisted of isopropanol and n-hexane.The detection wavelength and the flow rate were set at 254 nm and 0.7 mL/min,respectively.The effects of proportion of organic additives,alcohol displacer and temperature on the separation were investigated.The results indicated that eight chiral drugs were separated on chiral stationary phase of amylase ramification in normal phase chroma tographic system.The chromatographic retention and resolution of enantiomers were adjusted by factors,including the changes of the concentration of alcohol displacer in mobile phase,organic alkaline modifier and column temperature.It was shown that the resolution was improved with reducing concentration of alcohol displacer.When the concentration of organic alkaline modifier was 0.2%,the resolution and the peak shape were fairly good.Most racemates mentioned above had the best resolution at column temperature of 25℃.The best temperature should be kept unchanged in the process of separation so as to obtain stable separation results.
