EFFECT OF SUPPOSITORY BASES ON THE RELEASE PROPERTIES OF A POTENT ANTIMICROBIAL AGENT (C31-G)

C31G is a specific formulation which contains equal molar concentratio ns of alkyl N-betaine and alkyl N,N-dimethylamine oxide. Vaginal suppo sitories containing 500 mg of C31G, this potent antimicrobial substanc e, were prepared by the fusion method in a variety of Suppocire(R) and Witepsol(R) bases with different melting points and hydroxyl values. In vitro release and diffusion characteristics of C31G from different suppository bases were investigated using two different systems. The r elease from suppositories was determined by using a system without a m embrane and the diffusion rate of the released agent was determined th rough a semipermeable dialyzing tubing. Diffusion kinetics from suppos itories were evaluated in terms of the apparent dialytic rate constant s using the equation developed by Davis et al. From the results of in vitro studies, Witepsol H15 and Suppocire CM bases were selected as th e most suitable ones for the formulations of C31G vaginal suppositorie s, since it is imperative for topical formulations to release the acti ve substance in high proportions which are not absorbable by the mucos al membranes.