FORMULATION AND EVALUATION OF LINEZOLID LOADED SOLID LIPID NANOPARTICLES AS TOPICAL GEL

Linezolid loaded Solid Lipid Nanoparticles (SLN) were prepared and then incorporated in a topical gel as a carrier. The formulation was prepared by solvent injection method followed by probe sonication for reducing particle size. Excipients like lipids (Phospholipon 90H, Lipoid S-100, and Lipoid S-75) and emulsifier (Tween-80, Span-20, and poloxamer-407) were optimized using Taguchi L9 orthogonal design of an experiment. The optimized formulations were based on entrapment efficiency and were further evaluated for particle size, polydispersity index, zeta potential, in-vitro and ex-vivo studies. SLN4, SLN5, and SLN6 were optimized as their entrapment was more compared to other formulations. The results obtained were 93.05 nm of particle size, 0.252 is PDI, and -13.0 mV of zeta potential. From the in-vitro studies, it has been found that SLN5 with 2% of lipid is showing sustained-release followed by SLN4 (1.5%) and SLN6 (1%), and hence SLN5 was selected for evaluations like ex-vivo studies, and stability studies of gel. Ex-vivo permeation studies have shown sustained release of drugs with a flux of 11.22 ± 0.10 µg/cm² /hr. Skin retention was found to be 88.93 ± 0.6%. Stability studies were performed for one month at 4 °C ± 2 °C and evaluated for entrapment efficiency (%), drug content (%), appearance, and pH. Stability results suggested that the formulation was stable for one month. Linezolid loaded SLN for topical use was prepared successfully, and from the results, it was concluded that the prepared formulation can be used for localized bacterial infections, showing sustained drug release.