Exploring the potential of vaginal drug delivery: innovations, efficacy, and therapeutic prospects

Vaginal drug delivery has gained significant interest due to its numerous advantages, such as good blood flow, bypassing the first-pass effect, low systemic side effects, and potential for sustained release of pharmaceuticals. Initially targeting contraception and local effects from antibacterial, antifungal, and antiviral agents, recent advancements have broadened its scope. Notably, microbicide formulations showed promise against sexually transmitted diseases, offering superior protection and effective hormone therapies due to the vagina's large surface area and high permeability. The main agents used in vaginal delivery include contraceptives, prostaglandins, steroids, and antimicrobial substances, administered through tablets, suppositories, ointments, gels, creams, and vaginal rings. However, challenges such as slow dissolution and short residence time necessitate novel delivery systems. Mucoadhesive polymers are particularly valuable for enhancing drug absorption and extending treatment options. Comparative studies indicate that vaginal absorption of drugs like human growth hormone and insulin surpasses other parenteral routes. The development of standardized in vitro and in vivo testing methods remains crucial due to the diverse drug systems. While vaginal drug delivery offers benefits, such as high vascularization, low enzymatic activity, and increased bioavailability, it also faces drawbacks, including limited drug compatibility, sensitivity to vaginal pH, patient compliance issues, and potential local irritation. This review aims to elucidate the pathway, propose standardized methods for specific therapeutic areas, and highlight novel formulations like hydrogels and lipid nanoparticles for treating various diseases.