% protein bound; therefore, dialysis is unlikely to be of benefit.
11 DESCRIPTION
JALYN (dutasteride and tamsulosin hydrochloride) Capsules contain dutasteride (a selective inhibitor of both the type1 and type2 isoforms of steroid 5 alpha-reductase, an intracellular enzyme that converts testosterone to dihydrotestosterone (DHT) and tamsulosin (an antagonist of alpha1A-adrenoceptors in the prostate). Each JALYN Capsule contains the following:
One dutasteride oblong, opaque, dull-yellow soft gelatin capsule, containing 0.5mg of dutasteride dissolved in a mixture of butylated hydroxytoluene and mono-di-glycerides of caprylic/capric acid. The inactive ingredients in the soft-gelatin capsule shell are ferric oxide (yellow), gelatin (from certified BSE-free bovine sources), glycerin, and titanium dioxide.
Tamsulosin hydrochloride white to off-white pellets, containing 0.4mg tamsulosin hydrochloride and the inactive ingredients: methacrylic acid copolymer dispersion, microcrystalline cellulose, talc, and triethyl citrate.
The above components are encapsulated in a hard-shell capsule made with the inactive ingredients of carrageenan, FD&C yellow 6, hypromellose, iron oxide red, potassium chloride, titanium dioxide, and imprinted with “GS7CZ” in black ink.
Dutasteride: Dutasteride is a synthetic 4-azasteroid compound chemically designated as (5α,17β)-N-{2,5 bis(trifluoromethyl)phenyl}-3-oxo-4-azaandrost-1-ene-17-carboxamide. The empirical formula of dutasteride is C27H30F6N2O2, representing a molecular weight of 528.5 with the following structural formula:
Dutasteride is a white to pale yellow powder with a melting point of 242° to 250°C. It is soluble in ethanol (44mg/mL), methanol (64mg/mL), and polyethylene glycol 400 (3mg/mL), but it is insoluble in water.
Tamsulosin: Tamsulosin hydrochloride is a synthetic compound chemically designated as (-)-(R)-5-[2-[[2-(o-Ethoxyphenoxy)ethyl]amino]propyl]-2-methoxybenzenesulfonamide, monohydrochloride.
The empirical formula of tamsulosin hydrochloride is C20H28N2O5S•HCl. The molecular weight of tamsulosin hydrochloride is 444.97. Its structural formula is:
Tamsulosin hydrochloride is a white or almost white crystalline powder that melts with decomposition at approximately 234°C. It is sparingly soluble in water and slightly soluble in methanol, ethanol, acetone, and ethyl acetate.
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
JALYN is a combination of 2drugs with different mechanisms of action to improve symptoms in patients with BPH: dutasteride, a 5 alpha-reductase inhibitor, and tamsulosin, an antagonist of alpha1A-adrenoreceptors.
Dutasteride: Dutasteride inhibits the conversion of testosterone to dihydrotestosterone (DHT). DHT is the androgen primarily responsible for the initial development and subsequent enlargement of the prostate gland. Testosterone is converted to DHT by the enzyme 5 alpha-reductase, which exists as 2isoforms, type1 and type2. The type2 isoenzyme is primarily active in the reproductive tissues, while the type1 isoenzyme is also responsible for testosterone conversion in the skin and liver.
Dutasteride is a competitive and specific inhibitor of both type1 and type2 5 alpha-reductase isoenzymes, with which it forms a stable enzyme complex. Dissociation from this complex has been eva luated under in vitro and in vivo c |
