STUDIES ON A NEW SAMPLING SCHEME BY VARIABLES FOR THE CONTENT UNIFORMITY OF TABLETS

In order to work out a new criterion for the content uniformity of tablets that leads to more accurate results or requires less analytical work than those of USP XX, BP, and JP, we have advanced a new sampling inspection scheme by variables. The scheme consists of two subschemes, NEW and SMA, which are different only in the sample size required. By assaying of tablets made in our country which contain very small amount of active ingredients, 10 content distribution curves of tablet lots were obtained. The OC curves of USP XX, BP, JP, NEW, and SMA criteria under the normal and 10 real distributions were plotted through computing by means of computer simulation. Comprehensive comparisons of different criteria with regard to decision accuracy, adaptability to real distributions, effect of errors of analytical method and average sample size were made.