Deoxycholate hydrogels of betamethasone-17-valerate intended for topical use: In vitro and in vivo evaluation

Gelation of Sodium-Deoxycholate: Influenced by the Presence of a CorticosteroidBetamethasone-17-Valerate

“…In our previous study, the flow properties of just blank Na-DOC gels were reported [8]. The results of oscillation stress sweep tests indicated that blank and BMV incorporated gels showed a linear viscoelastic regimen (LVR) up to 0.6 Pa therefore the tests were conducted at 0.5 Pa.…”

“…At the end of 5 min, TEWL values obtained from 0.1% BMV incorporated gel (F2) applied rats, were higher than commercial cream and 0.05% BMV having formulation. In our previous study it was shown that, the release of drug from 0.1% BMV gel was significantly higher than (approximately 20 fold) commercial gel [8]. This might explain relatively lower values obtained with commercial cream.…”

“…Na-DOC is a low molecular weight polymer (414.5) with advantages as low melt viscosity, potential biocompatibility, biodegradability and the absence of toxic impurities [4] (Valenta et al, 1999). Na-DOC has been used as a penetration enhancer in various administration routes [5][6][7] and in our previous study Na-DOC has been optimized for the improvement of the skin delivery of betamethasone-17-valerate (BMV) [8]. BMV is the gold standard of topical corticosteroids and it is used as a reference in the clinical studies for the registration of new glucocorticosteroids [9].…”

“…BMV is a medium potency glucocorticoid, and it can be found as topical dosage forms like cream, ointment, lotion and foam all with a strength at 0.1 % w/w of betamethasone base [10]. In our previous study the enhanced in vitro flux and higher in vivo pharmacodynamic responses in rats were determined, in comparison with a commercial product of BMV [8].…”

“…Na-DOC is able to form gels due to the formation of the helical macromolecular complex from the bile acid steroid when in contact with excess buffer system [4,8]. BMV has a steroid ring also and it is susceptible to an acid and base catalyzed isomerization in aqueous and semi-solid formulations resulting in an acyl group migration from position C17 to the more stable C21 position of the steroid ring system [11].…”