Formulation Design and in vitro Characterization of Gastroretentive Floating Acyclovir Tablets

Geoffrey K Kiriiri; Lucy J Tirop; Shital M Maru; Dennis S B Ongarora; Alex Mwangi; Agnes Mathenge

Geoffrey K Kiriiri Department of Pharmaceutical Chemistry, Pharmaceutics and Pharmacognosy, Faculty of Health Sciences, University of Nairobi, P.O Box 19676-00202, Nairobi, Kenya
Lucy J Tirop Department of Pharmaceutical Chemistry, Pharmaceutics and Pharmacognosy, Faculty of Health Sciences, University of Nairobi, P.O Box 19676-00202, Nairobi, Kenya
Shital M Maru Department of Pharmaceutical Chemistry, Pharmaceutics and Pharmacognosy, Faculty of Health Sciences, University of Nairobi, P.O Box 19676-00202, Nairobi, Kenya
Dennis S B Ongarora
Alex Mwangi Department of Pharmaceutical Chemistry, Pharmaceutics and Pharmacognosy, Faculty of Health Sciences, University of Nairobi, P.O Box 19676-00202, Nairobi, Kenya
Agnes Mathenge Department of Pharmaceutical Chemistry, Pharmaceutics and Pharmacognosy, Faculty of Health Sciences, University of Nairobi, P.O Box 19676-00202, Nairobi, Kenya

Keywords: Acyclovir, gastroretentive floating; bioavailability; simplex lattice mixture design; controlled drug release; dissolution models

Abstract

Acyclovir is a thymidine kinase enzyme inhibitor used in the management of herpes zoster. Doses above 400mg exhibit poor bioavailability necessitating frequent administration to achieve the required therapeutic serum concentrations. This study aimed to design, formulate, and characterize floating tablets with enhanced bioavailability due to improved gastric retention time. The simplex lattice mixture design was employed to guide polymer proportions. Independent variables included polymers HPMC K100M, HPMC K4M, and Carbopol. The dependent variables were the floating lag time, total floating time and the cumulative drug release at 3, 6, and 8 hours, respectively. Formulation F2 exhibited the most desirable profile with a floating lag time and total floating time of 142 seconds and 14 hours, respectively and cumulative drug release at 3, 6, and 8 hours of 38.3%, 66.0% and 81.2 %, respectively. The findings indicate the feasibility of fabricating a commercially viable floating acyclovir tablet exhibiting extended gastric retention time and a controlled drug release profile.