title: Design and development of microemulsion drug delivery system of acyclovir for improvement of oral bioavailability.
abstract: The main purpose of this work was to develop an oral microemulsion formulation for enhancing the bioavailability of acyclovir. A Labrafac-based microemulsion formulation with Labrasol as surfactant and Plurol Oleique as cosurfactant was developed for oral delivery of acyclovir. Phase behavior and solubilization capacity of the microemulsion system were characterized, and in vivo oral absorption of acyclovir from the microemulsion was investigated in rats. A single isotropic region, which was considered to be a bicontinuous microemulsion, was found in the pseudoternary phase diagrams developed at various Labrasol:Plurol Oleique:Labrafac ratios. With the increase of Labrasol concentration, the microemulsion region area and the amount of water and Labrafac solubilized into the microemulsion system increased; however, the increase of Plurol Oleique percentage produced opposite effects. The microemulsion system was also investigated in terms of other characteristics, such as interfacial tension, viscosity, pH, refractive index, diffusion, and bioavailability. Acyclovir, a poorly soluble drug, displayed high solubility in a microemulsion formulation using Labrafac (10%), Labrasol (32%), Plurol Oleique (8%), and water (50%). The in vitro intraduodenal diffusion and in vivo study revealed an increase of bioavailability (12.78 times) after oral administration of the microemulsion formulation as compared with the commercially available tablets.
authors.affiliation: Drug Delivery Research Laboratory, MS University of Baroda, Pharmacy Department, Vadodara, India.
authors.forename: Pradip Kumar
authors.initials: PK
authors.lastname: Ghosh
authors.forename: Rita J
authors.initials: RJ
authors.lastname: Majithiya
authors.forename: Manish L
authors.initials: ML
authors.lastname: Umrethia
authors.forename: Rayasa S R
authors.initials: RS
authors.lastname: Murthy
mesh_terms: D000212:Acyclovir / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000284:Administration, Oral; D000818:Animals; D000998:Antiviral Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers; D016503:Drug Delivery Systems; D004655:Emulsions / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D051381:Rats; D012995:Solubility
chemical_list: D000998:Antiviral Agents; D004337:Drug Carriers; D004655:Emulsions; D000212:Acyclovir