A study was undertaken to evaluate the intertablet dosage variation in a number of different products by the use of automated instrumentation. Representative samples of actual production runs were used; an analysis of the data is presented.
LTHOUGH PRODUCT DOSAGE is expressed on an
A individual compressed tablet basis, potency testing utilizes an analytical sample which is a composite of many tablets. An assay procedure will often read: "Weigh and finely powder not less than 20tablets. Weigh accurately a portion of the powder, equivalent to about. . ."
(1). Such procedures give information on the average tablet assay; however, they give no information on the individual tablets. For example, if half of the tablets were 50% high in potency and half 50% low, the composite sample would still assay satisfactorily. Considerable interest has recently been shown in studying this topic as exemplified in reports by Moskalyk, et al. (Z), Garrett (3), and Evers (4).
Suggestions have been made to modify the presently accepted practice of assaying a composite sample and to assay individual tablets (5,6). Because of the difficulty of performing large numbers of assays, these studies have been limited to a relatively small sample, usually less than 100, which may not be representative of modern large scale production lots. For this reason, the nature of the distribution of individual tablet assays has not been established. Such information is necessary before the need for a change in existing procedures can be established and corrective action devised.
Recent work in this laboratory has made available automated chemical instrumentation (7-9) capable of automatically analyzing 20 tablets per hour. This facilitates the collection of a large number of assays. This paper presents assay and weight variation data on round,