Also available in 10 mg 25 mg 50 mg 200 mg 500 mg 1 mL 10 mM (in DMSO) and bulk. Please contact Fisher for quotes. Tenofovir Disoproxil Fumarate (GS-1278 Disoproxil Fumarate) is a pro-drug fumaric acid salt form of tenofovir a nucleoside reverse transcriptase inhibitor analog of adenosine. Tenofovir disoproxil fumarate is prescribed to treat HIV and chronic hepatitis B virus (HBV) in adults. purity: 99%