LIPOSOMES AND SOLID LIPID NANOPARTICLES AS LIPID-BASED NANOCARRIERS FOR TARGETED AND CONTROLLED DRUG DELIVERY

Lipid-based nanoparticles have emerged as promising drug delivery systems for achieving targeted and controlled drug release. Conventional drug delivery systems often suffer from several limitations such as poor bioavailability, systemic toxicity, rapid drug degradation, and lack of site-specific targeting. Nanotechnology-based carrier systems, particularly lipid-based nanoparticles such as liposomes and solid lipid nanoparticles (SLNs), have been developed to overcome these challenges and improve therapeutic outcomes. Liposomes are vesicular carriers composed of phospholipid bilayers capable of encapsulating both hydrophilic and lipophilic drugs, whereas solid lipid nanoparticles consist of solid lipid matrices that provide enhanced stability and controlled drug release. Various preparation methods including thin film hydration, reverse phase evaporation, highpressure homogenization, and solvent evaporation are used to produce lipid nanoparticles with desirable characteristics. Characterization techniques such as particle size analysis, zeta potential measurement, drug entrapment efficiency, and electron microscopy are essential for evaluating nanoparticle quality and stability. Lipid nanoparticles enable targeted drug delivery through passive and active targeting mechanisms and provide controlled drug release at the desired site of action. These nanocarriers offer several advantages including biocompatibility, biodegradability, reduced toxicity, improved bioavailability, and enhanced therapeutic efficacy. Lipid-based nanoparticles have wide applications in cancer therapy, gene delivery, vaccine delivery, antimicrobial therapy, and brain targeting. Recent advances such as PEGylated liposomes, nanostructured lipid carriers, and stimuli-responsive nanoparticles have further improved drug delivery efficiency. Future developments in personalized medicine and large-scale production are expected to enhance their clinical applications.