Fosamprenavir Calcium Salt

• CAT Number: I002734
• CAS Number: 226700-81-8
• Molecular Formula: C25H34N3O9PS • Ca
• Molecular Weight: 623.7
• Purity: ≥95%
• Synonyms: calcium;[(2R,3S)-1-[(4-aminophenyl)sulfonyl-(2-methylpropyl)amino]-3-[[(3S)-oxolan-3-yl]oxycarbonylamino]-4-phenylbutan-2-yl] phosphate
• Target: HIV Protease
• Solubility: 10 mM in H2O
• Storage: Store at -20°C
• InChIKey: PMDQGYMGQKTCSX-HQROKSDRSA-L

GW433908 is a phosphate ester prodrug of the antiretroviral protease inhibitor amprenavir, with improved solubility over the parent molecule and a potential for reduced pill burden on current dosing regimens; GW433908G is the calcium salt of the prodrug.IC50 Value:Target: HIV Proteasein vitro: There were no significant changes in buprenorphine or PI plasma levels and no significant changes in medication adverse effects or opioid withdrawal. Increased concentrations of the inactive metabolite buprenorphine-3-glucuronide suggested that darunavir-ritonavir and fosamprenavir-ritonavir induced glucuronidation of buprenorphine[1].in vivo: Fosamprenavir-ritonavir administered with methadone did not alter plasma amprenavir pharmacokinetics compared with historical control data; nor did it alter the unbound R-methadone at 2 and 6 hours after methadone dosing. Pharmacodynamic indexes remained essentially unchanged after adding fosamprenavir-ritonavir to methadone [2]. After a high-fat meal compared with fasting, (1) the bioavailability of GW433908G suspension was decreased by 20% and Cmax by 41%, and (2) for GW433908G tablets, there was no influence on AUC(12% lower Cmax). After a low-fat meal compared with fasting, (1) there was bioequivalence for GW433908G tablets, but (2) bioavailability was decreased by 23% for amprenavir capsules (Cmax was also lower, by 46%) [3].Clinical trial: Study of an Investigational Regimen Including FDA Approved HIV Drugs In HIV-Infected Pediatric Subjects. Phase 2

Reference

[1]. Gruber VA, Rainey PM, Moody DE, Interactions between buprenorphine and the protease inhibitors darunavir-ritonavir and fosamprenavir-ritonavir. Clin Infect Dis. 2012 Feb 1;54(3):414-23.

[2]. Cao YJ, Smith PF, Wire MB, Pharmacokinetics and pharmacodynamics of methadone enantiomers after coadministration with fosamprenavir-ritonavir in opioid-dependent subjects. Pharmacotherapy. 2008 Jul;28(7):863-74.

[3]. Falcoz C, Jenkins JM, Bye C, Pharmacokinetics of GW433908, a prodrug of amprenavir, in healthy male volunteers. J Clin Pharmacol. 2002 Aug;42(8):887-98.