Bioadhesive vaginal tablets of natamycin were formulated with different bioadhesive
polymers such as carbopol 971p, carbopol 974p, hydroxypropyl methylcellulose, and sodium
carboxymethylcellulose. Physical tests were applied to the tablets. The bioadhesive tablets were
evaluated for drug release rate and swelling behaviour in citrate buffer solution and
bioadhesive strength to mucosal tissue of cow vagina. The swelling of the tablets containing
carbopol 974p was found to last for up to 6 hr in citrate buffer solution. The force necessary to
detach the tablets from the vaginal tissue was found to be dependent on the concentration and
type of the bioadhesive polymer. The bioadhesive polymers were found to decrease the drug
release rate. However, inclusion of polyethylene glycol 6000 in the formulations increased the
released amount of the drug from 6.35% to 38.83% after 12 h. The bioadhesive tablets were
clinically evaluated in volunteers suffering from vaginal candidiasis and compared with
conventional natamycin vaginal tablets. It was found that the bioadhesive tablets were more
effective than the conventional tablets as they lasted about 4 days in the vaginal cavity and this
could sustain the drug release and lead to better patient compliance. Accelerated stability
studies were carried out and showed that the selected formulations were stable for not less than
2.5 years.