Transdermal Delivery of Bioidentical Progesterone with a Steroid 5α-Reductase Inhibitor (Dutasteride): a Pilot Study

Abstract

Purpose: Bioavailability of transdermal progesterone is low and variable. This may be attributed to transdermal metabolism by the 5α-reductase enzymes or the direct transport to the saliva. The objective of the current study was to evaluate the effect of enzyme inhibition on the bioavailability of transdermal progesterone. Serum and salivary progesterone levels were evaluated to gain a better insight into the mechanism progesterone transport across the skin. Method: Twenty postmenopausal women with a Follicle Stimulating Hormone > 40iu/L were recruited to take part in the study. The subjects were randomly allocated to either dutasteride (n=10) or placebo (n=10). Each group applied either 500mg of non ionic cream or dutasteride cream (2mg/g) to the right arm for 2 weeks. This was followed by applying 500mg of progesterone or progesterone dutasteride cream (equivalent to 40mg of progesterone) for a further 2 weeks. On day 30 blood and saliva were collected for over 12 hours and progesterone concentration was measured. Results: The baseline progesterone concentration on day zero was 0.1 ng/ml. On day 30 baseline progesterone levels increased significantly (p

The Potential of Pharmaceutical Hydrogels in the Formulation of Topical Administration Hormone Drugs

“…However, ready-touse hydrogel-based vaginal formulations of progesterone are available (Table 2). Research is currently underway to develop a hydrogel preparation that will ensure the stability of Prog during its passage through the skin [142]. The subject of analysis by Valenta et al [35] was the evaluation of the effect of permeation enhancers such as propylene glycol, urea and laurocapram on the percutaneous absorption of progesterone (Prog) from carbopol hydroalcoholic gels.…”

Update on medical and regulatory issues pertaining to compounded and FDA-approved drugs, including hormone therapy

“… 64 , 65 Administering progesterone orally or transdermally at a high enough dose to ensure sufficient bioavailability is challenging. 66 , 67 Many CBHT regimens incorporate nonoral progesterone, yet no adequate RCTs have established any delivery method of progesterone besides oral as effective or capable of protecting the endometrium from estrogen's effects. 7 , 32 , 60 , 68…”