Formulation Development and Evaluation of Apremilast Nanoemulsion

Apremilast is a selective phosphodiesterase 4 inhibitor administered orally in the treatment of moderate-to-severe plaque psoriasis and active psoriatic arthritis. It is classified as class IV drug as per BCS classification so it indicates low solubility and lower permeability through the skin. Therefore the objective of the research is to improve permeability of Apremilast through the skin and improve solubility by using oil and surfactant by formulating Nanoemulsion. Nanoemulsion was prepared by selecting Captex 355, Cremophore RH 40, Labrafil and Propylene glycol as the oil, surfactant,co-surfactant and co-solvent respectively after solubility study. Pseudo-ternary phase diagrams were constructed to find out the optimum ratio of oil: Smix (surfactant: co-Surfactant). Simple lattice design was applied to the optimization of the prepared nanoemulsion. The nanoemulsion was evaluated for Physical parameter, pH, Droplet size, zeta potential, in-vitro diffusion study etc. Results of Droplet size measurements, zeta potential and % drug diffusion indicated A5 batch optimized batch than other formulation of the nanoemulsion. So, optimized formulation further tested for Skin irritation study and stability study.The Apremilast loaded stable Nanoemulsion system was prepared and various process variables were evaluated. Batch A5 was selected as an optimized batch containing 10 % Captex 355, 40 % Smix (Cremophore RH 40 and Labrafil) and 50% water. Optimized batch was found to be stable after three month at ambient condition of temperature and humidity, giving reproducible results when evaluated.