PREPARATION AND EVALUATION OF IN SITU GEL CONTAINING ACYCLOVIR

*Sreenimya M.P. and Sujith S. Nair

ABSTRACT

In situ gel dosage forms were successfully used as drug delivery systems to prolong the residence time and to reduce the frequency and amount of administration. The main objective was to prepare and evaluate oral mucoadhesive in situ gel containing acyclovir based on the concept of pH triggered system. The system utilizes polymers that exhibit sol to gel phase transition due to change in specific physico-chemical parameters. A pH triggered system consisting of carbopol 934P along with hydroxypropylmethylcellulose was used to prolong the release of acyclovir, Formulations were evaluated for sol-gel temperature, gelling capacity, pH, viscosity, spreadability, gel strength Mucoadhesive force, drug content and in vitro release. The use of carbopol as in situ gel forming system was sustained by the property to transform into stiff gels when the pH was raised. The viscosity was found to be in the range 82-199 centipoise for the sol, where for the gel was up to 1594 centipoise. The maximum gel Strength and mucoadhesion was found to be up to 50.8dynes/cdynes/c2 and 6219 dynes/cm2 respectively. The optimized formulations were able to release the drug up to 97.2%. In situ gel formulation of Acyclovir with mucoadhesive properties was found to be promising for prolonging buccal residence time and thereby better therapeutic effects.

Keywords: Acyclovir, In Situ Gel, Mucoadhesive, Carbopol, HPMC.