Injectable Liposomal Formulations for Sustained Release of Anticancer Drugs

Liposomal formulations have been a lot of interest as an improved drug delivery system to overcome the key drawbacks of traditional chemotherapy namely low solubility, premature metabolism, nonspecific biodistribution, and overwhelming systemic toxicity. Liposomes increase the stability of anticancer drugs like doxorubicin and topotecan, extend plasma circulatory time and offer targeted and steady drug delivery by entrapping these drugs within lipid bi-layers. These formulations take advantage of passive targeting using the increased permeability and retention (EPR) effect of tumor vasculature and can be further refined using active methods that include PEGylation or ligand conjugation to allow selective tumor accumulation. Preclinical experiments show that liposomal encapsulation enhances intratumoral drug concentrations, therapeutic efficacy, and off-target toxicity and permits increased effective dose. Besides, the safety assessment in animals showed reduced cardiotoxicity, nephrotoxicity, and hematological toxicity, which points to their good safety profile. Regardless of the issues surrounding batch-to-batch variability, premature release, or burst release of drugs and the lack of consistency in large-scale production, recent studies on lipid composition optimization, multifunctional surface modification, and standardized production protocols highlight how liposomal formulations can be translated to clinical use. Altogether, injectable liposomal systems offer a flexible, convenient, and efficient system of advanced cancer therapy with better pharmacokinetics, greater tumor targeting, lower systemic toxicity, and combination therapy, which can be used to achieve optimal anticancer effects.