A Novel Intrauterine Device for the Extended Tissue-Specific Release of Estradiol and Norethindrone to Treat the Genitourinary Syndrome of Menopause

The genitourinary syndrome of menopause (GSM) is a prevalent condition impacting a substantial number of women globally. Presently, the management of GSM typically entails the administration of estrogen via oral, dermal, or vaginal routes for a prolonged period of time. This study involves the development of a polymer-based hollow cylindrical delivery system loaded with estradiol hemihydrate (E2) for prolonged delivery to the uterine cavity (EPHCD) combined with a norethindrone acetate (NETA)-loaded polymeric matrix (NLPM), with both units placed onto an intra-uterine device to form a multi-component drug delivery system for the management of GSM (MCDDS). In developing EPHCD, a central composite design (CCD) was employed to evaluate and optimize the impact of formulation factors on EPHCD release and unit weight loss. The optimized EPHCD was further assessed for its chemical integrity, surface morphology, hydration characteristics, release behavior, ex vivo permeation and cytocompatibility. The optimized EPHCD, which featured a high drug load (10%) and low ethyl cellulose-to-polycaprolactone ratio (EC-to-PCL, 10%), demonstrated favorable attributes with a cumulative drug release and weight loss of 23.78 ± 0.84% and 2.09 ± 0.21%, respectively, over a 4-week testing period. The release kinetics were further noted to obey the Peppas-Sahlin model. Evaluation of MCDDS revealed an in vitro drug release comparable to the individual units, with permeation studies displaying an initial increase in the rate of flux for both drugs during the first 2 h, followed by a subsequent decrease. Moreover, the MCDDS components showed good cytocompatibility against NIH/3T3 cells, with cell viability of more than 70%. Upon evaluation of the MCDDS system, the results of this study highlight its potential as a viable sustained-release intrauterine platform for the treatment of GSM.