Famciclovir, 泛昔洛韦

Famciclovir is an orally bioavailable prodrug form of the antiviral guanosine analog penciclovir. Famciclovir is rapidly deacetylated and oxidized in vivo to form penciclovir, which is active against clinical isolates of herpes simplex virus 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV) in a plaque reduction assay with IC50 values of 1.6, 6, and 12 μM, respectively. Both famciclovir and the product of its deacetylation, 6-deoxypenciclovir, are oxidized in vitro by human, guinea pig, and rat liver aldehyde oxidase, with 6-deoxypenciclovir being converted to penciclovir. Peak plasma concentrations of penciclovir (mean 3.5 μg/ml) are reached 0.5 hours after oral administration of famciclovir (40 mg/kg) in rats. Famciclovir (25 mg/kg) has a longer half-life in dogs, with peak concentrations of penciclovir (mean 4.4 μg/ml) in plasma occurring after 3 hours.

Famciclovir is an antiviral drug, which is predominantly used in the treatment of herpes virus infection. It is an inactive prodrug, which on administration, undergoes rapid biotransformation to penciclovir.

Pharmaceutical secondary standards for application in quality control, provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards.

Famciclovir is a diacetyl 6-deoxy prodrug analog of the antiviral agent penciclovir. Orally administered, famciclovir in vivo is converted to penciclovir triphosphate, which is active against the Herpes viruses, including herpes simplex 1 and 2 and varicella-zoster. This agent inhibits the replication of viral DNA by interfering competitively with DNA polymerase. (NCI04)

Famciclovir is a nucleoside analogue and antiviral agent used in therapy of herpes zoster and simplex virus infections. Famciclovir is associated with a low rate of mild-to-moderate serum ALT elevations during therapy, but has not been associated with instances of clinically apparent liver injury.

Famciclovir, also known as famvir or BRL-42810, belongs to the class of organic compounds known as purines and purine derivatives. These are aromatic heterocyclic compounds containing a purine moiety, which is formed a pyrimidine-ring ring fused to an imidazole ring. Famciclovir is a drug which is used for the treatment of acute herpes zoster (shingles). also for the treatment or suppression of recurrent genital herpes in immunocompetent patients and treatment of recurrent mucocutaneous herpes simplex infections in hiv infected patients. Famciclovir exists as a solid, slightly soluble (in water), and an extremely weak acidic (essentially neutral) compound (based on its pKa). Famciclovir has been detected in multiple biofluids, such as urine and blood. Within the cell, famciclovir is primarily located in the cytoplasm.

Famciclovir is the orally available form of penciclovir. Penciclovir is an antiviral agent and acyclic guanine derivative. Penciclovir has proven efficient in the treatment of Herpes Simplex type 1 and 2 (HSV1 and HSV2) infection. Penciclovir is transformed by the virus into an active derivative able block the deoxyguanosine triphosphate substrate binding site of the HSV polymerase.

Title: Famciclovir

CAS Registry Number: 104227-87-4

CAS Name: 2-[2-(2-Amino-9H-purin-9-yl)ethyl]-1,3-propanediol diacetate (ester)

Additional Names: 9-[4-acetoxy-3-(acetoxymethyl)but-1-yl]-2-aminopurine; FCV

Manufacturers' Codes: BRL-42810

Trademarks: Oravir (SKB); Famvir (SKB)

Molecular Formula: C14H19N5O4

Molecular Weight: 321.33

Percent Composition: C 52.33%, H 5.96%, N 21.79%, O 19.92%

Literature References: Prodrug of penciclovir, q.v. Prepn: M. R. Harnden, R. L. Jarvest, AU 85 47560; eidem, US 5246937 (1986, 1993 both to Beecham); M. R. Harnden et al., J. Med. Chem. 32, 1738 (1989). HPLC determn in plasma and urine: J. R. McMeekin et al., Anal. Proc. 29, 178 (1992). Review of metabolism and mode of action: R. A. Vere Hodge, Antiviral Chem. Chemother. 4, 67-84 (1993). Series of articles on pharmacology and pharmacokinetics: ibid. Suppl. 1, 37-68 (1993). Review of clinical efficacy in herpes zoster and genital herpes: R. Circelli et al., Antiviral Res. 29, 141-151 (1996).

Properties: White shiny plates from ethyl acetate-hexane, mp 102-104°. uv max (methanol): 222, 244, 309 nm (e 27500, 4890, 7160). Sol in water (25°): >25% w/v initially; rapidly ppts as sparingly sol monohydrate (2-3% w/v). Freely sol in acetone, methanol; sparingly sol in ethanol, isopropanol.

Melting point: mp 102-104°

Absorption maximum: uv max (methanol): 222, 244, 309 nm (e 27500, 4890, 7160)

Therap-Cat: Antiviral.

Keywords: Antiviral; Purines/Pyrimidinones.