FG90 chitosan as a new polymer for metronidazole mucoadhesive tablets for vaginal administration.

Topical administration of the antibacterial metronidazole (MET) represents the most common therapy in the treatment of bacterial vaginosis (BV). The formulations generally available for BV therapy are creams, gels, vaginal lavages and vaginal suppositories. In this study, a new dosage form, containing MET, was developed with the aim to realize vaginal mucoadhesive tablets by including bioadhesive polymers as chitosan (FG90C), polyvinylpyrrolidone (PVPK90) and polycarbophil (PCPAA1), blended in different ratios. All formulations were characterized by studies of DSC, friability, hardness, hydration, mucoadhesion, in vitro release and antibacterial activity. All polymer mixtures employed were used to prepare tablets with the compactness and hardness so as allow the application on vaginal mucosa. FG90C performances improved in particular when mixed to PVPK90 (1:1 ratio). This kind of delivery system is suitable for formulating MET for topical application representing a good alternative to traditional dosage forms for vaginal topical administration.