Testing the purity or stability of amlodipine maleate comprises assaying for the presence of amlodipine aspartate or amlodipine maleamide

摘要

Method for testing the purity or stability of a sample of amlodipine maleate or a pharmaceutical dosage form comprising amlodipine maleate comprises assaying the sample for the presence of amlodipine aspartate or amlodipine maleamide. Independent claims are also included for the following: (1) a method comprising analyzing largely pure amlodipine aspartate or amlodipine maleamide under a series of conditions to provided a reference standard for this series of conditions; (2) a process comprising separating amlodipine maleate from both amlodipine aspartate and amlodipine maleamide; (3) a process comprising mixing amlodipine maleate with excipient(s), producing a batch of tablets or capsules comprising the mixture, analyzing a sample of the tablets or capsules, comparing the result with a reference standard for amlodipine aspartate or amlodipine maleamide, and selling or releasing the batch if the amlodipine aspartate or amlodipine maleamide content is no more than 1% by weight of amlodipine maleate.