Also available in 1 mg, 2 mg, 10 mg, 25 mg, 50 mg, 100 mg and bulk. Please contact Fisher for quotes.Fosamprenavir Calcium Salt (GW433908G) (GW433908G) is a phosphate ester prodrug of the antiretroviral protease inhibitor Amprenavir, with improved solubility. Fosamprenavir Calcium Salt has Anti-HIV infection. Purity 99.59%