Rifabutindrug info

Rifabutin capsules, USP for oral administration contain 150 mg of the rifamycin antimycobacterial agent rifabutin, USP, per capsule, along with the inactive ingredients, microcrystalline cellulose, sodium lauryl sulfate, colloidal silicon dioxide, magnesium stearate, gelatin, red iron oxide, titanium dioxide, shellac, and potassium hydroxide. The chemical name for rifabutin is 1',4-didehydro-1-deoxy-1,4-dihydro-5'-(2-methylpropyl)-1-oxorifamycin XIV (Chemical Abstracts Service, 9th Collective Index) or (9 S,12 E,14 S,15 R,16 S,17 R,18 R,19 R,20 S,21 S,22 E, 24 Z )-6,16,18,20-tetrahydroxy-1'-isobutyl-14-methoxy-7,9,15,17,19,21,25-heptamethyl-spiro [9,4-(epoxypentadeca[1,11,13]trienimino)-2 H -furo[2',3':7,8]naphth[1,2-d] imidazole-2,4'-piperidine]-5,10,26-(3 H,9 H )-trione-16-acetate. Rifabutin has a molecular formula of C 46 H 62 N 4 O 11, a molecular weight of 847.02 and the following structure: Rifabutin is a red-violet powder soluble in methanol and slightly soluble in alcohol and water. Its log P value is 4.493±1.556 (at 25˚C). FDA approved dissolution test specifications differ from the USP. Chemical Structure