Formulation and In Vitro Evaluation of Niosomal Gel of Loratadine: A Novel Topical Agent for Allergic Skin

Loratadine is an efficacious, non-drowsy antihistaminic molecule prescribed for allergic skin. The conventional oral dosage form is associated with various side effects, limited and variable absorption. The present study attempts to improve the effectiveness of the drug by formulating a niosome loaded hydrogel of loratadine for treating allergic skin. Ether injection method was used to prepare the niosomes of loratadine using Box Behnken design. Particle size analysis, surface charge, surface morphology (atomic force microscopy), compatibility (Fourier transform infrared spectroscopy), thermal (differential scanning calorimetry), and surface characteristics (powder X-ray diffraction) study were done to evaluate the drug-loaded niosomes. The optimized formulation was incorporated into two types of gelling systems. The nanogels were evaluated for rheological and mechanical properties, in vitro, ex vivo permeation and skin irritation studies. The Box Behnken design was found to be productive for the formulation of nano-sized (109.99 nm) and stable -37.5 mV niosomes of loratadine. The atomic force microscopy study revealed the formation of unilamellar niosomes, no incompatibility was detected between drug and excipients through Fourier transform infrared spectroscopy study. The differential scanning calorimetry and powder X-ray diffraction study reported the confinement of drugs in the niosomal core. The nanogels had good rheological and mechanical properties. The ex vivo study revealed the maximum penetration of the drug from the gel base of Xanthan gum, and no skin irritation was reported from the nanogel. The formulation and evaluation of niosomal gel of loratadine were found to have satisfactory permeation and can be a promising alternative approach for the administration of loratadine in the treatment of skin allergy.