Comparison of Pharmacokinetic Characteristics and the Safety between Amlodipine Maleate Tablet 5 mg and Amlodipine Besylate Tablet 5 mg

BACKGROUND: Amlodipine is a third-generation dihydropyridine calcium channel blocker for treating hypertension. Though marketed primarily as a besylate salt, there have been some efforts to find other comparable salts. Among them, maleate is the salt that has been considered favorable for many drugs. The aim of this study was to compare the pharmacokinetics, as well as safety and tolerability of amlodipine maleate with amlodipine besylate. METHODS: This study was open, randomized, two-period crossover design investigated in twelve healthy male volunteers over a 144 h period after administrating two forms of amlodipine 5 mg, respectively. Each period was separated with 2 weeks. Plasma concentrations of amlodipine were determined by liquid chromatography-tandem mass spectrometry. Safety profiles were assessed by vital signs, physical examinations, electrocardiograms, laboratory testing and adverse events monitoring. RESULTS: All subjects were completed this study. Geometric mean ratios (GMRs) of amlodipine maleate/amlodipine besylate of Cmax and AUClast for amlodipine were 0.92 (90 % confidence interval, 0.81 ~ 1.05) and 1.05 (0.96 ~ 1.16), respectively. No serious adverse events were reported, and no clinically relevant changes were observed in safety profiles during this trial. CONCLUSION: Pharmacokinetics, tolerability and the safety were comparable between amlodipine maleate and amlodipine besylate in healthy individuals.

Content Determination of Main Component and Related Substances in Amlodipine Maleate Dispersible Tablets by HPLC / 中国药房

OBJECTIVE: To established an HPLC method for the determination of main component and related substances in amlodipine maleate dispersible tablets. METHODS: The separation was performed on a Lichrospher C18 column. The mobile phase consisted of methanol-0.03 mol?L-1 potassium dihydrogen phosphate (70 ∶ 30) at the flow rate of 1 mL?min-1. The detection wavelength was set at 237 nm and column temperature was 30 ℃. RESULTS: The linear range of amlodipine maleate were 31.94～127.75 ?g?mL-1 (r=0.999 8, n=5). The average recovery was 99.5% (RSD=0.39%, n=9). The contents of related substance were all lower than 0.38%. CONCLUSION: The method is simple, rapid, accurate and specific for the quality control of amlodipine maleate dispersible tablets.