A Simple and Economical Approach/Concept to Evaluate Quality of Pharmaceutical Products Based on an Improved Dissolution Testing Methodology

Abstract

Often the quality of drug products is evaluated based on chemical tests, commonly described in different phar- macopeias such as the USP. These tests includes: assay (potency), uniformity of dosage form and dissolution test. Pres- ently, these tests are conducted separately with three procedures. Furthermore, dissolution tests are also conducted using multiple product-specific procedures. This makes the current practice of evaluation of the quality of pharmaceutical prod- ucts complex and resource (human and financial) intensive. Recently a new improved dissolution methodology, based on a modified spindle known as crescent-shaped spindle, has been proposed. Using the proposed methodology, all these tests may be conducted based on a single dissolution test procedure. Such an approach would, therefore, provide a simpler al- ternative to the current practice with significant economical benefits. The attributes of the proposed approach which lead to the concept of product evaluation based on a single dissolution test procedure, are described here by testing a number of diltiazem products having different strengths and release characteristics. The quality of drug products is evaluated based on chemical tests commonly described in different pharmacope- ias such as USP. In general tests are conducted to establish presence of the expected amount of drug in the product (po- tency), uniformity or consistency of drug content in a prod- uct, such as, from tablet to tablet, and expected drug dissolu- tion or release characteristics of a product. At present, these tests are conducted separately with at least three procedures. A new spindle known as crescent-shaped spindle has been proposed for improved drug dissolution testing (1-3). The superiority of the new spindle appears to be due to its effi- cient extraction ability, because of improved product- medium interaction in the dissolution vessel. It may be ar- gued that as all the above mentioned tests are based on the extraction of drug from a product, the new approach based on the new spindle may provide a common approach for these tests. This would provide a simpler alternative to the current practice, with a significant economical benefit. This article provides a discussion and experimental evi- dence showing that a simpler and more relevant testing ap- proach based on dissolution testing may be used for an over- all evaluation of the quality of pharmaceutical products.