Preliminary Studies on Solid Lipid Microparticles of Loratadine for the Treatment of Allergic Reactions via the Nasal Route

Abstract

Purpose: To formulate solid lipid microparticles (SLM) of loratadine (LRT) for the treatment of allergic reactions via the nasal route.Methods: Microparticles were prepared by emulsion congealing technique. The drug content of microparticles was analysed. Drug/excipient compatibility and crystallinity characteristics of microparticles were investigated by Fourier Transform Infrared Spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Particle size distribution was determined by laser diffraction (LD). Drug release from microparticles was compared to that from conventional vehicles (O/W emulsion, gel andoleageneous cream) using Franz-type diffusion cells.Results: Drug content of microparticles was > 87.96 %. FT-IR and DSC analysis indicated that the drug and excipients were compatible for at least 6 months at room temperature after production. Microparticle size was between 86 ± 5.63 ìm and 184 ± 13.21 ìm while mean droplet size of O/Wemulsion was 76 ± 3.45 ìm. Release profiles of LRT from microparticles were significantly different from those of O/W emulsion, gel and oleageneous cream (p < 0.05). In the case of conventional vehicles,increase in the hydrophilicity of the vehicles led to increase in drug release rate. Drug release fitted generally to zero order kinetics as well as Korsmeyer-Peppas model for one of the SLM formulations, indicating non-Fickian drug release (super case II transport).Conclusion: SLM provided LRT release for a longer period than the conventional vehicles. However, in vivo studies are required to ascertain the effectiveness of the formulations.Keywords: Loratadine, Solid lipid microparticles, Allergy, Controlled drug delivery, Transnasal delivery