SPL Set ID: 976f1b69-dd96-4815-b11b-839ce1c45633

Tacrolimus, previously known as FK506, is the active ingredient in tacrolimus capsules. Tacrolimus is a calcineurin-inhibitor immunosuppressant produced by Streptomyces tsukubaensis. Chemically, tacrolimus is designated as [3 S -[3 R *[ E (1 S*, 3 S*, 4 S* )],4 S*, 5 R*, 8 S*, 9 E, 12 R* ,14 R*, 15 S*, 16 R*, 18 S*, 19 S*, 26 aR* ]]-5,6,8,11,12,13,14,15,16,17,18,19,24,25,26,26a-hexadecahydro-5,19-dihydroxy-3-[2-(4-hydroxy-3-methoxycyclohexyl)-1-methylethenyl]-14,16-dimethoxy-4,10,12,18-tetramethyl-8-(2-propenyl)-15,19-epoxy-3H-pyrido[2,1-c][1,4]oxaazacyclotricosine-1,7,20,21(4H,23H)-tetrone, monohydrate. The chemical structure of tacrolimus is: Tacrolimus has a molecular formula of C 44 H 69 NO 12 •H 2 O and a formula weight of 822.03. Tacrolimus appears as white crystals or crystalline powder. It is practically insoluble in water, freely soluble in ethanol, and very soluble in methanol and chloroform. Tacrolimus capsules, USP are available for oral administration containing the equivalent of 0.5 mg, 1 mg or 5 mg of anhydrous tacrolimus. In addition, each capsule contains the following inactive ingredients: croscarmellose sodium, hypromellose, lactose monohydrate, and magnesium stearate. The tacrolimus capsule shell for 0.5 mg strength consists of gelatin, titanium dioxide and yellow iron oxide. The tacrolimus capsule shell for 1 mg strength consists of black iron oxide, gelatin, red iron oxide, titanium dioxide, and yellow iron oxide. The tacrolimus capsule shell for 5 mg strength consists of red iron oxide, gelatin, and titanium dioxide. Tacrolimus capsules, USP 0.5 mg, 1 mg and 5 mg are printed with edible black ink. The black ink is comprised of ammonia, black iron oxide, butyl alcohol, potassium hydroxide, propylene glycol, and shellac. USP Dissolution test 2 and Organic Impurities procedure 2 used.