European Journal of Biomedical and Pharmaceutical Sciences

DESIGN AND STATISTICAL OPTIMIZATION OF ACYCLOVIR LOADED HOLLOW MICROSPHERES USING CELLULOSE ACETATE

Shailaja Pashikanti, Lokesh Srinivas Vanapalli, Haritha Isukapatla, Prasanna Jonnada, Arun Santhosh K.S., Ramkishan Ajmeer, Swathi Putta and Bhavani Boddeda*

ABSTRACT

Acyclovir is an antiviral drug, having absorption window in the upper intestinal tract and an absolute bioavailability of 30%. Its short biological half-life and recommended adult oral dosage necessitates the development of a controlled release formulation. The present investigation conceptualizes a specific technology to ascertain the gastro retentivity of acyclovir by non-aqueous solvent evaporation method using cellulose acetate. A 32 full factorial design was employed to elucidate the effect of formulation factors of drug loaded hollow microspheres. The effect of two factors, polymer concentration (X1) and stirring speed (X2) as independent variables were studied on Y1(% yield value), Y2(% entrapment efficiency), Y3(size of microsphere), Y4(% buoyancy), Y5(T50, time to release 50 % of drug) and Y6(T100, time to release 100% drug) selected as dependent variables. The micromeritic properties like angle of repose, Hausner’s ratio and Carr’s index were within the limits suggesting good flow properties. The percent yield value, entrapment efficiency and buoyancy were about 79-97%, 49-70% and 10-92%, respectively. The size of microspheres (76-254 μm) was also found to be increasing with increase in polymer concentration and decreasing with rpm. In vitro dissolution test shows T50 at 2.0-2.9 h and T100 at 4-11 h for different formulations exhibiting zero order release kinetics following non-fickian diffusion release mechanism. The optimal formula contains X1 (polymer) as 1095 mg and X2 (stirring speed) as 1183 rpm with a desirability of 0.91. The prepared hollow microspheres of acyclovir could be used as twice a day capsule for enhancing the therapeutic activity.

Keywords: Acyclovir, Bioavailability, Factorial Design, Microspheres.