In Vitro Release of Neomycin Sulfate from Polymeric Films

Abstract

A study was made of the release of neomycin sulfate from films containing ethyl cellulose or a polyamide. These films were plasticized using hexadecyl alcohol and/or tributyl citrate. Neomycin sulfate was incorporated into the film, and the release of neomycin in a desorbing media of distilled water was measured by periodically removing a sample of desorbing media and determining the neomycin sulfate content spectrophotometrically. The release of neomycin sulfate from these films was also determined microbiologically. This was carried out by measuring the zone of inhibition surrounding a circular disc containing neomycin sulfate which had been placed onto the surface of a Petri dish containing suitable media inoculated with Bacillus subtilis. Hexadecyl alcohol was noted to suppress or decrease the release of neomycin sulfate from ethyl cellulose and polyamide films. Release of neoraycin sulfate from films of ethyl cellulose plasticized with tributyl citrate showed an increase. The results of the microbiological determination were similar to the spectro-photometric results and indicated that the release of neomycin sulfate from ethyl cellulose/tributyl citrate systems was time dependent.