Drug Release from Compression Molded Films: Preliminary Studies with Pilocarpine

It was found that the incorporation of pilocarpine into a hydrophilic thermoplastic matrix such as hydroxypropyl cellulose by the compression molding technique allowed the facile preparation of various pilocarpine salt/hydroxypropyl cellulose compositions.

The pilocarpine release characteristics were evaluated for several compositions of this type. This study showed that the choice of pilocarpine salt and the hydroxypropyl cellulose molecular weight can significantly affect pilocarpine release from the polymer matrix. It was found that from the highest molecular weight grade of hydroxypropyl cellulose pilocarpine release was faster for the more soluble hydrochloride salt than for the nitrate salt. In addition, when a new pilocarphe salt, pilocarpine pamoate, was incorporated into the same matrix, a dramatic decrease in pilocarpine release' was exhibited. When pilocarpine pamoate was incorporated into three different molecular weight grades of hydroxypropyl cellulose, dramatic differences in pilocarpine release rate were observed. In general, it was found that pilocarpine release was faster from the lower vseosity grades of hydroxypropyl cellulose.

This manuscript discusses the method of preparation for compression molded films, the release rate testing procedure, the effects of agitation and temperature, and variations in the drug salts and the matrix composition.