Mucoadhesive polymeric systems for vaginal drug delivery: a systemic review / Sistemas poliméricos mucoadhesivos para la liberación vaginal de fármacos: revisión sistemática

ABSTRACT Intravaginal drug administration has many advantages in comparison to other delivery routes: its local and systemic effect, lower dosages, and easiness of administration. Furthermore, makes it a reliable and comfortable way of therapy. This route can be used to prevent and treat a wide range of conditions including, sexually transmitted infections (STIs), hormonal treatment, birth control, and cancer treatment. The dosage forms may vary from ovules, tablets, rings, gels, creams, films and many more; lately adding the mucoadhesiveness to the characteristics to reduce the waste of active molecules. This review focuses on the way mucoadhesive polymeric systems have been applied in vaginal delivery. This review presents a bibliographical compilation of results from various investigations published in scientific databases: Science Direct, SciELO, and PubMed Central. Results compiled demonstrate that the intravaginal drug administration can be an alternative form of medication for women with more stable and prolonged results than traditional routes requiring lower doses and avoiding the first-pass effect.

RESUMEN La administración de fármacos por vía intravaginal cuenta con múltiples ventajas a comparación de otras rutas, puede lograr un efecto tanto local como sistémico, las dosis requeridas son menores, facilidad de administración entre otras, hacen que esta forma de administración sea confiable y cómoda. Esta vía de administración puede ser empleada para prevenir y tratar diferentes trastornos, como enfermedades de transmisión sexual, desordenes hormonales, anticonceptivos y tratamiento contra el cáncer. La presentación de las dosis puede variar, desde óvulos, tabletas, anillos, geles, cremas, películas entre otros, agregando a esta, en los últimos tiempos, la característica de mucoadhesividad para reducir el desecho de moléculas activas. Este trabajo se enfoca en las aplicaciones que han tenido los sistemas poliméricos mucoadhesivos en la vía intravaginal. La bibliografía recolectada se obtuvo de bases de datos como Science direct, SciELO, y PubMed Central. Los resultados obtenidos demuestran que la administración de fármacos por vía intravaginal puede ser una forma alternativa para medicación en mujeres, con resultados más estables y prolongados que otras rutas, requiriendo menores dosis y evitando el efecto de primer paso.

Thermosensitive In Situ Gel Of Tinidazole In Treatment Of Bacterial Vaginosis: Formulation And Evaluation

Bacterial Vaginosis (BV) is the leading cause of vaginal discharge. Because of its big surface area, wealthy blood supply, avoidance of the first-pass effect and high permeability to many drugs, the vagina offers a promising location for local impact as well as systemic drug delivery. In situ gels give several benefits, such as ease of administration in the respective body cavities, elevated spreadability at certain temperatures, reduced administration frequency, improved patient compliance and comfort compared to standard dosage forms. Tinidazole (TNZ) can give effective treatment over the BV. In situ gel of TNZ containing polaxomer 407and HPMC E100 or carbopol 941NF was optimized on the basis of various evaluation parameters. Gelation temperature (Tgel) and pH of all batches was found in range of 36.6 to38.0 ºC and 4.20 to 5.03, viscosity was found in range of 1100-2050 cps at 25ºC and 4800-6530 cps at 37ºC. The Spredability was found in range of 16-20 cm. From these evaluation parameters we selected best combination for the mucoadhesive property, antimicrobial study, in vitro drug release and for HET CAM irritation study. The optimized formulation gives satisfactory results. In this study we also compare the performance of two mucoadhesive polymer. Based on maximum desirability and cost effectiveness, in situ vaginal gel containing 20% polaxomer and 0.5% HPMC E100 could be considered as a highly promising treatment for bacterial vaginosis.

Vaginal Mucosa – A Promising Site for Drug Therapy.

The vagina provides a promising site for local effect as well as systemic drug delivery because of its large surface area, rich blood supply, avoidance of the first-pass effect, relatively high permeability to many drugs and self-insertion. The pharmaceuticals currently used for vaginal delivery includes those that provide protection against viral infections, including Acquired Immune Deficiency Syndrome (AIDS) and other sexually transmitted infection (STDs). The anti infectives used in treatment of vulvovaginal infection, and vaginitis includes chemicals, for example, clotrimazole, miconazole, clindamycin, sulfonamide and probiotics. Currently, there is a variety of pharmaceutical products available on the market designed for intravaginal therapy (tablets, creams, suppositories, pessaries, foams, solutions, ointments, intravaginal rings, films and gels). However, their efficacy is often limited by a poor retention at the site of action due to the self-cleansing action of the vaginal tract. The vaginal cell lining is covered with a viscous and elastic gel. The physicochemical properties of this gel can influence the rate of diffusion from the bulk to the site of absorption. The choice of absorption model depends totally on the questions to be answered with respect to the test compound being studied. Having studied this review, thus one should able to: understand the anatomy and physiology of the vagina as site of drug administration; understand the pharmaceuticals preferred for administration via vagina; understand the different vaginal delivery system; understand the in vitro models to study vaginal permeability.