Abstract
Testosterone is integral to men's sexual and overall health, but there is a gradual decline in the ageing male. The topical administration of testosterone is a valuable option as a supplement (replacement) therapy to alleviate hypogonadal symptoms. The clinical efficacy of a compounded testosterone 5% topical gel was assessed retrospectively in a male patient in his seventies by evaluating the laboratory testing of the serum total testosterone and the results of a validated androgen deficiency questionnaire. After treatment, the patient's hypogonadal symptoms improved and the serum total testosterone level achieved was considered clinically optimal. The skin permeation of the testosterone topical gel (biological testing) was evaluated in vitro using the Franz finite dose model and human cadaver skin, and it is shown that testosterone can penetrate into and through ex vivo human skin. Testosterone therapy is often prescribed for extended periods, and consequently, it is crucial to determine the beyond-use date of the compounded formulations. The analytical testing involved a valid, stability-indicating assay method for compounded testosterone 0.5% and 20% topical gels. This multidisciplinary study shows evidence supporting topically applied testosterone's clinical efficacy and the compounded formulations' extended stability. Personalized, topical testosterone therapy is a promising alternative in current therapeutics for hypogonadal patients.