Investigation of Pharmaceutical Equivalency in Pioneer and Generic Enteric-Coated Tablets.

In order to investigate the pharmaceutical equivalency of four propentofylline enteric-coated tablets (a pioneer preparation and 3 generic preparations), a quantitative analysis, disintegration testing and dissolution testing were all performed to evaluate them.The mean contents of propentofylline in each preparation ranged from 96 to 102%. All of the tested materials conformed to the findings for the disintegration test for enteric-coated articles in the thirteeth revised edition of Japanese Pharmacopoeia (JP). However, at the end of the disintegration test with the 1st test medium (pH 1.2), swelling was observed in one or more of the 6 tested tablets for two of the generic preparations. Although no release of propentofylline was recognized, the core of the swollen tablets had completely disintegrated inside the enteric coating film in one of the two swollen generic preparations. When doing the same test aften placing the disks in gastric fluid, the propentofylline finally dissolved in the medium after 120 min. The dissolution test was performed with a paddle (100 rpm) according to JP using a 0.05 M phosphate buffer at pHs of 6.5 and 7.2. The dissolutions were complete in less than 60 min at both pHs, and they were faster at pH 7.2 for all preparations. However, the dissolution was significantly delayed, and the 75% dissolution time was also significantly prolonged for one of the three generic preparations at both pHs when compared to the other preparations.All of the propentofylline enteric-coated preparations were acceptable based on the JP criteria, however, the pharmaceutical equivalency of the generic preparations to the pioneer preparation heve not yet been obtained. As a result, the changes between generic preparations and pioneer preparations are therefore considered to be considerable, especially ragarding enteric coated preparations