Dendrimer entrapped microsponge gel of dithranol for effective topical treatment

Dithranol is one of the important topical agents for the treatment of psoriasis, a chronic inflammatory skin disease with aberrant differentiation of keratinocytes. However, its application is troublesome and inconvenient because of its associated side effects, including staining, burning sensation, irritation, and necrotizing effect on the diseased cells as well as on the normal cells. The purpose of the current investigation was to explore the potential of poly(amido) amine (PAMAM) dendrimers in the topical delivery of dithranol through a novel microsponge based gel. Generation-4 (G4) dendrimers were incorporated into the microsponge based gel formulation by quasi-emulsion solvent diffusion method with varying concentration of polymers, and evaluated for the morphology of the formulation, encapsulation efficiency and skin irritation potential. Percentage yield of the formulation was found to be 66.28%, whereas encapsulation efficiency was ranged between 71.33% to 49.21%, and an average particle size was ranged between 28 ± 1.12 μm to 130 ± 1.01 μm. Surface morphology of developed microsponge was confirmed by scanning electron microscopy, revealed micro-porous nature. The optimized microsponge formulation was found to be stable and recorded non-irritant during cutaneous application of the experimental animals. Further, the pharmacokinetic outcomes of study were showed prolong penetration of the drug through the skin, equivalent to the marketed formulation of dithranol. Therefore, it could be conferred that the microsponge formulation of the PAMAM entrapped dithranol can produce prolonged efficacy without producing toxicities to the skin, and thus can effectively be projected in the treatment of diseases like psoriasis.