Mucoadhesive Solid Lipid Microparticles (SLMs) for controlled release of a corticosteroid in the chronic obstructive pulmonary disease treatment

Therapeutic efficacy of inhaled drugs is limited by rapid clearance from the site of action due to absorption into systemic circulation or metabolic degradation by alveolar macrophages. Drug delivery systems offer new solutions to clinical problems especially in the treatment of pulmonary diseases. In particular, Solid Lipid Microparticles (SLM) in the range of 3-5 µm are suggested as systems for delivery of therapeutics to the lung as, because of their size, they are able to deposit into secondary bronchi, avoiding systemic absorption typical of alveolar regions. Here, we describe two novel different SLMs prepared with chitosan and alginate for sustained release of fluticasone propionate (FP). The presence of mucoadhesive polymers allows SLMs to adhere better to the mucous layer on the respiratory epithelium as compared with conventional carriers. We also studied the biocompatibility and the effectiveness of the drug-loaded SLM compared to the free drug in controlling senescence and inflammatory processes in cigarette smoke extracts (CSE). Data herein reported show that FP-loaded SLM are more effective than FP alone in controlling oxidative stress. Since lung inflammaging is an important contributing factor into the development of COPD, a therapeutic approach using FP loaded microparticles, could be a promising strategy for the treatment of this disease.