THE EFFECT OF FORMULATION ON THE ANTIMICROBIAL ACTIVITY OF CETYLPYRIDINIUM CHLORIDE IN CANDY BASED LOZENGES

Purpose. The purpose of this investigation was to determine the influe nce on the antimicrobial activity of cetylpyridinium chloride of the v arious components of the formulation of each of six candy based lozeng es. Methods. In vivo activity was investigated using six volunteers by determining the reduction in colony forming units recoverable from th e oropharynx after sucking each lozenge separately on different days. In vitro determinations investigated the relative activity of aqueous solutions of the lozenges, the effect on activity of additional active ingredients, pH and lozenge base ingredients against separate inocula of each of the test organisms Staphylococcus aureus, Streptococcus py ogenes and Candida albicans. Results. Both in vivo and in vitro result s showed that the pH of the dissolved lozenge solution was the single most influential readily adjustable formulation parameter which signif icantly influenced the activity of cetylpyridinium chloride activity i n candy based lozenges. Conclusions, Lozenges containing cetylpyridini um chloride as the active ingredient should be formulated at a pH grea ter than 5.5.