Famciclovir is a synthetic antiviral active pharmaceutical ingredient (API) and an orally administered prodrug of penciclovir. It is used for the treatment of infections caused by herpes viruses, including herpes zoster (shingles), herpes simplex infections, and recurrent genital herpes, according to applicable approved indications.
After oral administration, Famciclovir is rapidly converted to penciclovir, which inhibits viral DNA replication.
Famciclovir is a nucleoside analogue antiviral prodrug. Its active metabolite, penciclovir, selectively inhibits herpesvirus DNA polymerase and interferes with viral DNA synthesis.
CAS Number: 104227-87-4
Molecular Formula: C₁₄H₁₉N₅O₄
Molecular Weight: 321.34 g/mol
Famciclovir is converted in vivo to penciclovir. Penciclovir is phosphorylated preferentially in virus-infected cells and its active triphosphate form inhibits herpesvirus DNA polymerase.
Its antiviral effects include:
Famciclovir is used in pharmaceutical formulations for:
The exact indication, dosage and treatment duration depend on the approved formulation and applicable regulatory labeling.
Famciclovir is a small-molecule antiviral API with defined chemical and physicochemical characteristics. Pharmaceutical-grade material requires appropriate control of identity, assay, related substances and other quality attributes.
Typical quality evaluation may include:
Pharmaceutical-grade Famciclovir should comply with the applicable approved specification and relevant regulatory requirements.
A qualified supplier should provide Certificate of Analysis (CoA), specification sheet, SDS/MSDS, batch traceability and applicable regulatory documentation.
Store Famciclovir in a tightly closed container, protected from excessive moisture, heat and direct light, according to the manufacturer's approved storage and stability requirements.
| Parameter | Specification |
|---|---|
| Appearance | White to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | NLT 98.0% by HPLC |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.2% |
| Heavy Metals | NMT 10 ppm |
| pH (1% Solution) | 2.0 – 4.0 |
| Individual Impurity | ≤ 0.5% |
| Total Impurities | ≤ 1.5% |
| Water Content | NMT 0.5% |