Tamsulosin hydrochloride is an antagonist of alpha1A adrenoceptors in the prostate.
Tamsulosin HCl is (-)-( R)-5-[ 2-[[ 2-( 0-ethoxyphenoxy) ethyl] amino] propyl]-2-methoxybenzenesulfonamide, monohydrochloride. Tamsulosin HCl occurs as white crystals that melt with decomposition at approximately 230 C. It is sparingly soluble in water and in methanol, slightly soluble in glacial acetic acid and in ethanol, and practically insoluble in ether.
The empirical formula of tamsulosin HCl is C20H28N2O5S . HCl. The molecular weight of tamsulosin HCl is 444.98.
Each FLOMAX capsule for oral administration contains tamsulosin HCl 0.4 mg, and the following inactive ingredients: methacrylic acid copolymer, microcrystalline cellulose, triacetin, polysorbate 80, sodium lauryl sulfate, calcium stearate, talc, FD& C blue No. 2, titanium dioxide, ferric oxide, gelatin, and trace amounts of shellac, industrial methylated spirit 74 OP, n-butyl, alcohol, isopropyl alcohol, propylene glycol, dimethylpolysiloxane, and black iron oxide E172.