Topical Administration of Mometasone Furoate - A Combined Impedance Spectroscopy and In Vitro Drug Diffusion Study

Although TGs have been shown to be efficient in treatment of various skin diseases, their use can result in both local and systemic side effects. Some of the local side effects are skin atrophy, rosacea, and corticoid acne, while the major systemic side effects are hypothalamic-pituitary-adrenal-axis suppression along with diabetes mellitus and hypertension [1,7-9]. Mometasone furoate (MF) is a potent steroid (according to the European Union classification system) with relatively low risk of systemic side effects [1]. The low risk of side effects is largely due to the high lipophilicity (lg P 4.5), resulting in low solubility in aqueous fluids such as blood. Systemic uptake is further reduced by the ability of MF to degrade in aqueous solvents at pH values above 4.9 [10]. For topical formulations, factors such as their ability to hydrate the skin, drug solubility, and release rate of the drug can also affect the bioavailability of the steroid and are therefore important to consider [11]. In this study we evaluate topical application of two different types of MF creams, both containing the same amount of drug (i.e. Elocon® 0.1% cream, Merck, Sharp & Dohme B.V., the Netherlands (Cream A) and Ovixan® 1mg/mL cream, Galenica AB, Malmo, Sweden (Cream B)). According to SWEDIS 2007 [12], Cream A is water-in-oil (w/o) emulsion with white soft paraffin (54 wt %) as the main component of the continuous oil phase. Only 3 wt% of the cream consists of water, and hexylene glycol (12 wt %) is used as co-solvent for MF. In contrast, Cream B is an oil-in-water (o/w) emulsion with coconut oil (8 wt %) dispersed in the continuous aqueous phase. This cream contains approximately 50 wt% water and propylene glycol (25 wt %) is used as a co-solvent for MF. A previously reported clinical study [13] showed that use of these two different types of formulations gave similar vasoconstrictive properties and equal clinical response.