Studies on vaginal bioadhesive tablets of acyclovir.

Bioadhesive vaginal tablets were prepared using poly(acrylic acid) (PAA); Methylcellulose (MC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC) and hydroxypropylmethyl cellulose (HPMC) as bioadhesive polymers in different concentrations and acyclovir as drug by direct compression technique (DCT) and wet granulation technique (WGT). Physical tests were applied to the tablets. The swelling behavior of vaginal tablets in distilled water, lactic solution and cow vagina, acyclovir release rate in lactic solution and bioadhesion to vaginal mucosa in cow vagina, in situ, were investigated. Swelling of the tablets containing HPC, CMC and MC was very rapid and caused disintegration of the tablets. The swelling behaviour of the tablets containing HPMC lasted 6 h in lactic solution. The force (N) necessary to detach the tablets from the vaginal tissue was found to depend on concentration and type of the bioadhesive polymer. The tablets containing HPMC needed the most detachment force.