Local application of danazol-loaded hyaluronic acid hydrogel to endometriosis in a rat model

Objective: To evaluate the efficacy of a drug delivery system composed of danazol-loaded hyaluronic acid for local application to endometriosis. Design: Prospective, randomized Study. Setting: Academic research unit of the department of obstetrics and gynecology in a university hospital. Patient(s): Adult female Sprague-Dawley rats. Intervention(s): Danazol-loaded hyaluronic acid hydrogel (DZ-HA gel) was injected into the rat endometriosis model. Main Outcome Measure(s): Size and histological changes in experimental endometriosis, the concentration of danazol in the cyst wall and plasma, and estrous cycles were examined. Result(S): Histologically, DZ-HA gel-treated cysts displayed marked atrophy of the endometrial epithelium. Increased numbers of apoptotic cells and decreased numbers of proliferative cells were noted with 10 mg/mL DZ-HA gel. Size of treated cysts decreased to approximately 60% at 9 weeks after injection. The estrous cycles were not disturbed during DZ-HA gel treatment. Conclusion(S): Local injection of DZ-HA gel achieved endometrial atrophy of an experimental model of endometriosis without disturbing the sexual cycle. These results suggest that local application of DZ using this drug delivery system may prove useful for treating endometriosis.