A mucoadhesive, cyclodextrin-based vaginal cream formulation of itraconazole

Abstract

The development of vaginal medications, especially antifungal medications, requires that the drug is solubilized as well as retained at or near the mucosa for sufficient periods of time to ensure adequate bioavailability. Itraconazole is a broad-spectrum antifungal agent, which has been used for some time orally and intravenously but for which a vaginal formulation has not yet been developed. We present here a novel itraconazole formulation intended for vaginal use based on hydroxypropyl-β-cyclodextrin (HPβCD), a functional excipient that increases drug solubility and generates a mucoadhesive system in the presence of other ingredients. An aqueous phase was prepared by solubilizing itraconazole with HCl in the presence of propylene glycol and then adding an aqueous solution of HPβCD. After pH adjustment, the itraconazole/HPβCD solution was added to the oil phase (paraffin oil, trihydroxystearate, and cetyl dimethicon copolyol) and the desired cream containing 1%, 2%, and 2.5% drug obtained by homogenization. Primary irritation studies and subchronic toxicity studies using a rabbit vaginal model indicated that the formulation was safe, well tolerated, and retained in the vaginal space. Clinical investigations indicated that application of 5 g of a 2% cream was very well tolerated and itraconazole was not systemically absorbed. Additional studies in women found that the itraconazole cream was highly effective in reducing or eliminating fungal cultures with few adverse effects. These studies suggested that an HPβCD-based, emulsified wax cream formulation was a useful and effective dosage form for treating vaginal candidiasis.