Sildenafil Citrate

11 DESCRIPTION Sildenafil tablets, USP, an oral therapy for erectile dysfunction, is the citrate salt of sildenafil, a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5).​​​‍​​‍​​​​‍​​‍‍ Sildenafil citrate USP is designated chemically as 1-[[3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1 H -pyrazolo[4,3- d ]pyrimidin-5-yl)-4-ethoxyphenyl]sulfonyl]-4-methylpiperazine citrate and has the following structural formula: Sildenafil citrate USP is a white to off-white crystalline powder with a solubility of 3.5 mg/mL in water and a molecular weight of 666.7. Sildenafil tablets, USP are formulated as green, oval-shaped, beveled edge, biconvex, film-coated tablets equivalent to 25 mg, 50 mg and 100 mg of sildenafil for oral administration. In addition to the active ingredient, sildenafil citrate, each tablet contains the following inactive ingredients: microcrystalline cellulose, anhydrous dibasic calcium phosphate, croscarmellose sodium, magnesium stearate, colloidal silicon dioxide, hypromellose, hydroxypropyl cellulose, polyethylene glycol, titanium dioxide, FD & C Blue #1/brilliant blue FCF aluminum lake, D & C yellow # 10 aluminum lake. FDA approved dissolution test specifications differ from USP. str