A COMPREHENSIVE REVIEW OF ADVANCES IN DRUG DELIVERY SYSTEMS FOR INFLAMMATORY DISEASES AND PAIN MANAGEMENT: INNOVATIONS, CHALLENGES, AND FUTURE DIRECTIONS

Inflammatory diseases such as rheumatoid arthritis (RA), osteoarthritis (OA), ankylosing spondylitis, and other chronic pain disorders impose a substantial global health burden, often leading to persistent pain, reduced mobility, disability, and diminished quality of life. Conventional pharmacological management relies heavily on non-steroidal anti-inflammatory drugs (NSAIDs), among which Diclofenac Sodium is widely prescribed due to its potent analgesic, anti-inflammatory, and antipyretic effects. Diclofenac Sodium achieves its therapeutic action primarily through inhibition of cyclooxygenase (COX-1 and COX-2) enzymes, leading to reduced synthesis of prostaglandins, the mediators of inflammation and pain. However, conventional formulations are associated with significant challenges, including gastrointestinal (GI) irritation, cardiovascular risks, hepatic metabolism-related variability, and the need for frequent dosing due to its short plasma half-life. Innovative drug delivery systems (DDS) have been developed to overcome these limitations and enhance therapeutic outcomes. Recent advances include sustained-release oral formulations, lipid-based nanoparticles, hydrogels, transdermal patches, and microneedle-based delivery systems. These technologies aim to maintain stable drug concentrations, improve patient compliance, target inflamed tissues directly, and reduce systemic side effects. This review discusses the pharmacological basis of Diclofenac Sodium therapy, examines recent DDS innovations for its delivery, highlights key challenges such as drug stability, scalability, and patient adherence, and outlines future directions, including smart and bio-responsive delivery platforms.