A novel hydrogel-thickened microemulsion of dapsone for acne treatment: Development, characterization, physicochemical stability and ex vivo permeation studies

Abstract

Acne vulgaris is a common inflammatory skin condition, which has been reclassified as a chronic disease. The spectrum of topical acne treatments has expanded substantially in recent years and various topical medications including topical dapsone are available. Dapsone has special physicochemical properties that make its topical formulation challenging. The aim of this study was preparing a hydrogel-thickened microemulsion as a topical delivery system for dapsone. The microemulsions composed of dapsone (5%), isopropyl myristate, tween 80, diethylene glycol monoethyl ether, ethanol and water were prepared. The optimum microemulsion was modified with carbomer 940. Droplet size, pH, refractive index, conductivity, rheology of the optimized formulation, and skin permeation of dapsone through rat skin were evaluated. The optimized formulation significantly increased the skin permeation of dapsone in comparison to that of control gel. Although incorporation of menthol increased the particle size, the flux of microemulgel consisting of menthol (5%) was 2.51 times higher than that of the control. However, the skin absorption of the drug was less than 3%. Six month accelerated studies proved the physicochemical stability of microemulgels. The results of this research indicate that menthol based hydrogel-thickened microemulsion system could be a promising vehicle for topical delivery of dapsone.

Foray into Concepts of Design and Evaluation of Microemulsions as a Modern Approach for Topical Applications in Acne Pathology

“…By contrast with the anterior case, menthol was added as a penetration enhancer, while Carbomer 940 changed the rheological profile from liquid ME with Newtonian behaviour, through non-Newtonian ME which influenced the spreadability and skin dynamics. In accordance with the data presented in the Table 4, the addition of menthol 2.5-5% sustains the superior profile of the designed ME [314].…”

Effect of monoterpenes on ex vivo transungual delivery of itraconazole for the management of onychomycosis

“…Therefore, our hypothesis regarding negative effect of monoterpenes on itraconazole delivery to the nail was rejected. However, natural terpenes possess proved enhancement activity through skin . As skin infection and inflammation are caused by the dermatophytes associated with onychomycosis, the marketed topical dosage forms like PENLAC ® nail lacquer recommend the application of topical formulation over the entire nail plate and 5 mm of surrounding skin.…”

“…However, natural terpenes F I G U R E 1 Typical chromatograms of (1, black curve) itraconazole after extraction from nail; (2, red curve) blank sample; and (3, blue curve) a calibrator (2.0 µL mL −1 ) possess proved enhancement activity through skin. 27,28 As skin infection and inflammation are caused by the dermatophytes associated with onychomycosis, the marketed topical dosage forms like PENLAC ® nail lacquer recommend the application of topical formulation over the entire nail plate and 5 mm of surrounding skin. It is therefore important to consider drug delivery into the nail folds (skin surrounding the nail) to ensure complete topical treatment.…”

Exploring Acne Treatments: From Pathophysiological Mechanisms to Emerging Therapies

“…Topical dapsone, a sulfone medication, offers antimicrobial, anti-inflammatory, and potentially immunomodulatory actions for treating acne [153,154]. It is available as a 5% or 7.5% gel and reduces both inflammatory and non-inflammatory acne lesions [155,156].…”