Design and In Vivo Evaluation of Acitretin Solid Lipid Nanoparticles Loaded Gel for Topical Delivery

Solid lipid nanoparticles (SLNs) are very potential formulations for topical delivery of antifungal drugs. The main objective for this investigation is to develop and optimize the SLNs of Acitretin for the effective topical delivery. Acitretin loaded SLNs were prepared by hot homogenization followed by the ultra sonication using Taguchi’s design and based on the results further investigation was made using central composite design (CCD). The lipid Dynasan-116, surfactant poloxomer-188 and co surfactant egg lecithin resulted in better percent drug loading and evaluated for particle size, zeta potential, TEM, drug entrapment efficiency, in vitro drug release and stability. All parameters were found to be in an acceptable range. In vitro drug release of optimized SLN formulation (F2) was found to be 95.63±1.52%, whereas pure drug release was 30.12 after 60 min. The optimized formulation was incorporated into the gel. The drug content of Acitretin gel formulation was found to 99.86 ± 0.012% and the diameter of gel formulation was 6.9 ± 0.021 cm and that of marketed gel was found to be 5.7 ± 0.06 cm, indicating better spreadability of SLN based gel formulation. The viscosity of gel formulation at 5 rpm was found to be 6.1 x 103± 0.4 x 103 cp. The release rate (flux) of Acitretin across the membrane and excised skin differs significantly. It is assumed that SLN based gel due to its appropriate physicochemical properties, high skin permeation ability, higher accumulative uptake in skin and improved skin tolerability may be more suitable as a novel regime for topical administration of Acitretin. This topically oriented SLN based gel formulation could be useful in providing site-specific dermal treatment of psoriasis with minimal drug systemic availability and high skin tolerability.