The majority of testosterone binds to sex hormone-binding globulin (SHBG) and is biologically inactive. Testosterone also circulates unbound as a free hormone and is considered biologically active.Testosterone is metabolized primarily in the liver and also in peripheral tissue. Dihydrotestosterone (DHT) and estradiol (E2) are products of testosterone metabolism.
DHT is produced by reduction through the action of the enzyme 5- alpha reductase, which is present in genital tissue and skin. DHT is further metabolized to 3-alpha and 3-beta androstanediol. DHT binds with greater affinity to SHBG than does testosterone. E2 is produced by aromatisation of testosterone. 90% of testosterone is excreted in the urine as glucuronide and sulphate conjugates of testosterone and its metabolites.
Following AndroFeme® application to the skin, serum testosterone begins to rise within an hour of application. A steady-state level is achieved within 2 weeks of initiating therapy. A single daily application of 1ml via measured applicator (10mg testosterone) of AndroFeme® to the inner aspects of the forearm results in a serum concentration profile in the upper range to that observed in healthy young females.
AndroFeme® 1% w/v testosterone cream is a transdermal drug delivery system consisting of a white vanishing cream intended for use in women. AndroFeme® 1% w/v testosterone cream contains dl-α- tocopherol acetate (vitamin E) and almond oil formulated to optimise systemic absorption of the active ingredient. Also contains cetomacrogol 1000, cetostearyl alcohol, butylated hydroxytoluene, anhydrous citric acid, triethanolamine, carbomer 940, B & J Phenonip® and purified water.