title: Development and evaluation of a monolithic floating drug delivery system for acyclovir.
abstract: Acyclovir (ACV), a model drug for this study, is one of the most effective drugs against viruses of the herpes group. Absorption of orally administered ACV is variable and incomplete, with a bioavailability of ca. 15-30%. The drug is absorbed in the duodenum after oral administration and hence, preparation of a floating drug delivery system (FDDS) for ACV may increase oral absorption of the drug. ACV matrix tablets (200 mg) containing an effervescent base (sodium bicarbonate and citric acid) and a binary combination of hydroxypropyl methylcellulose (HPMC) K4M with carbopol or sodium carboxymethyl cellulose (Na CMC) or polyvinylpyrrolidone (PVP) and/or sodium alginate were prepared by the direct compression method. The tablets were evaluated for physicochemical properties and in vitro floating ability (floating lag-time and duration), bioadhesiveness and drug release. The drug release studies were carried out in 0.1 N HCl (pH 1.2) at 37±0.5°C. At appropriate time intervals, samples were withdrawn and assayed spectrophotometrically at λ(max)=259 nm. The floating test showed tablets containing 15% effervescent base had a floating lag time of 10-30 s and a duration of floating time of 24 h. The formulations containing HPMC-PVP, HPMC-Na CMC, HPMC-carbopol, and HPMC-sodium alginate released about 60-90% of their drug content during a 12-h period. Increasing carbopol caused slower drug release. We concluded that the proposed tablets with 15% effervescent base, 20-30% HPMC, 30% Na CMC (and/or 20% PVP or 20% sodium alginate) showed good floating and drug release properties in vitro, and should be considered as FDDS for ACV.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Naser
authors.initials: N
authors.lastname: Tavakoli
authors.forename: Jaleh
authors.initials: J
authors.lastname: Varshosaz
authors.forename: Farid
authors.initials: F
authors.lastname: Dorkoosh
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Motaghi
authors.forename: Lana
authors.initials: L
authors.lastname: Tamaddon
mesh_terms: D000212:Acyclovir / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000998:Antiviral Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D001682:Biological Availability; D016503:Drug Delivery Systems / Q000592:standards*; D013607:Tablets / Q000008:administration & dosage / Q000737:chemistry
chemical_list: D000998:Antiviral Agents; D013607:Tablets; D000212:Acyclovir