title: Biowaiver monographs for immediate release solid oral dosage forms: aciclovir.
abstract: Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing (biowaiver) for the approval of immediate release (IR) solid oral dosage forms containing aciclovir are reviewed. Aciclovir therapeutic use and therapeutic index, pharmacokinetic properties, data related to the possibility of excipient interactions and reported BE/bioavailability (BA) studies were also taken into consideration in order to ascertain whether a biowaiver can be recommended. According to the Biopharmaceutics Classification System (BCS) and considering tablet strengths up to 400 mg, aciclovir would be BCS Class III. However, in some countries also 800 mg tablets are available which fall just within BCS Class IV. Aciclovir seems not to be critical with respect to a risk for bioinequivalence, as no examples of bioinequivalence have been identified. It has a wide therapeutic index and is not used for critical indications. Hence, if: (a) the test product contains only excipients present in aciclovir solid oral IR drug products approved in ICH or associated countries, for instance as presented in this article; and (b) the comparator and the test product both are very rapidly dissolving, a biowaiver for IR aciclovir solid oral drug products is considered justified for all tablet strengths.
authors.affiliation: Facultad de Farmacia, Universidad de Valencia, Burjassot 46100, Valencia, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Arnal
authors.forename: I
authors.initials: I
authors.lastname: Gonzalez-Alvarez
authors.forename: M
authors.initials: M
authors.lastname: Bermejo
authors.forename: G L
authors.initials: GL
authors.lastname: Amidon
authors.forename: H E
authors.initials: HE
authors.lastname: Junginger
authors.forename: S
authors.initials: S
authors.lastname: Kopp
authors.forename: K K
authors.initials: KK
authors.lastname: Midha
authors.forename: V P
authors.initials: VP
authors.lastname: Shah
authors.forename: S
authors.initials: S
authors.lastname: Stavchansky
authors.forename: J B
authors.initials: JB
authors.lastname: Dressman
authors.forename: D M
authors.initials: DM
authors.lastname: Barends
mesh_terms: D000212:Acyclovir / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000284:Administration, Oral; D000998:Antiviral Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D001682:Biological Availability; D013810:Therapeutic Equivalency
chemical_list: D000998:Antiviral Agents; D000212:Acyclovir