Microemulsion-based hydrogel formulation for transdermal delivery of dexamethasone

Abstract

T he purpose of this study was to construct a microemulsion-based hydrogel formulation for the transdermal delivery of dexamethasone. Almond oil, olive oil, linseed oil, and nutmeg oil were screened as the oil phase. A microemulsionbased system was chosen due to its good solubilizing capacity and skin permeation capabilities. The pseudoternary phase diagrams for microemulsion regions were constructed using various oils, egg lecithin as the surfactant, isopropyl alcohol (IPA) as the cosurfactant, and distilled water as the aqueous phase. Microemulsion gel formulations were prepared using Carbopol and filled into a reservoir-type transdermal system. The ability of various microemulsion formulations to deliver dexamethasone through the rat skin was evaluated in vitro using Keshary Chien diffusion cells. In order to enhance permeation, the skin was treated with an abrading gel (apricot seed powder in hydrogel base). The in vitro permeation data showed that microemulsions increased the permeation rate of dexamethasone compared with the control. The optimum formulation consisting of 0.1% dexamethasone, 10% olive oil, 70% egg lecithin:IPA (2:1), and water showed a permeation rate of 54.9 µg/cm 2 /h. The studied microemulsion-based hydrogel was stable toward centrifugation test and was nonirritating to the skin. The pharmacodynamic studies indicated that microemulsion based on nutmeg oil demonstrated a significantly (P < 0.05) higher anti-inflammatory potential. The nutmeg oil-based transdermal microemulsion gel system demonstrated 73.6% inhibition in rat paw edema. Thus, microemulsion-based transdermal systems are a promising formulation for dermal delivery of dexamethasone.

Microemulsion-Based Oxyresveratrol for Topical Treatment of Herpes Simplex Virus (HSV) Infection: Physicochemical Properties and Efficacy in Cutaneous HSV-1 Infection in Mice

“…The selected ME was o/w type, and this was in accordance with previous studies. It was reported that o/w ME type showed high conductivity in the range of 10-100 μS/cm while w/o type showed lower conductivity levels (32,40,41). For the stability test, the HPLC peak of OR did not show any degradation peaks.…”

“…This may be affected by the ME formula with a permeation enhancer in reducing the diffusion barrier (32,40,41). As a commonly used transdermal enhancer, isopropyl myristate has been supposed to be able to increase permeation by fluidizing intercellular lipids in the stratum corneum or to increase drug solubility at the lipid part of the stratum corneum (42,43).…”

“…Receiver solution samples, 1.0-ml aliquots, were withdrawn periodically for 6 h (0, 0.25, 0.5, 0.75, 1, 2, 3, 4, 5, and 6 h) through the receiver compartment. The cells were refilled with receiver solution to keep the volume in the receiver compartment constant during the experiment (7,32). The content of OR in the receiver solution at each sampling time was measured for UV absorbance at 310 nm using a spectrophotometer.…”

Preparation and Microstructural Characterization of Griseofulvin Microemulsions Using Different Experimental Methods: SAXS and DSC

“…In some cases, the capacity of the ME to solubilize large amounts of lipophilics drugs can be advantageous as well. 16 The dispersed phase of a ME, aqueous or lipidic (o/w or w/o types) potentially serve as reservoir of both water-soluble and fat-soluble drugs which may be partitioned in external and internal phases. 13 Various techniques have been employed to study the size, shape and interactions of ME droplets.…”

Submicron polymeric particles prepared by vibrational spray-drying: Semisolid formulation and skin penetration/permeation studies

“…On the other hand, the same group described that Transfersomes ® with DEX and hydrocortisone were able to deliver the drug to viable skin layers allowing the reduction of the required dose 4 to maintain its efficacy compared to conventional vehicles [20]. More recently, Chandra, Sharma & Irchhiaya [21] developed microemulsions prepared with several oils and lecithin as surfactant and isopropyl alcohol as co-surfactant for transdermal delivery of DEX. Formulation based on olive oil showed the best in vitro drug permeation, while the microemulsion based on nutmeg oil showed higher in vivo anti-inflammatory activity.…”