Topical delivery of doxepin using liposome containing cream: An emerging approach in enhancing skin retention

• Published in: Pakistan journal of pharmaceutical sciences 2023-09, Vol.36 (5), p.1497-1506
• Main Authors: Asl, Ainaz Didevar, Bohlooli, Shahab, Dadkhah, Masoomeh, Shirmard, Leila Rezaie
• Format: Article
• Language: English
• Subjects: Atopic dermatitis; Complications and side effects; Doxepin; Drug therapy; Patient outcomes
• ISSN: 1011-601X
• DOI: 10.36721/PJPS.2023.36.5.REG.1497-1506.1

Conventional formulation of topical doxepin has similar antihistaminic effects as oral doxepin; however, its efficacy is limited due to poor localized effects on the skin. This study was designed to compare the ex vivo permeation and retention of two topical doxepin formulations; liposomal cream and plain cream. Methods: Doxepin-containing liposomes were prepared with the thin-film hydration method and assessed for size, size distribution, morphology, entrapment efficiency (EE%) and stability Using rat skin specimens in a Franz diffusion cell. Doxepin concentration in skin and receptor fluid was quantified by a validated HPLC method. The optimized liposomal formulation represented a uniform shape with narrow size distribution and an average diameter of 208.7 [+ or -] 5.6nm. EE% of doxepin was 79 [+ or -] 1.3 and the liposomes were stable at least for six weeks at 4[degrees]C. Ex vivo studies showed that while a significantly higher amount of doxepin has passed through the skin and entered the receptor compartment from conventional dosage form (47.06 [+ or -] 2.5 [micro]g/cm2vs 11.20 [+ or -] 0.6 [micro]g/[cm.sup.2] for liposomal formulation), liposomal doxepin favoured accumulation in dermis and epidermis. These results suggest that the liposomal doxepin cream is an effective and easy-to-use formulation and may improve the cutaneous retention of doxepin, thus decreasing its systemic side effects. Keywords: Doxepin, liposome, ex vivo study, atopic dermatitis.