Chronic pain management remains a significant global health challenge, with current approaches heavily reliant on opioids and systemic NSAIDs that carry serious risks of dependence and toxicity. This study presents a novel multi-population microencapsulated topical analgesic system designed to offer sustained, dual-action pain relief through entirely natural, low-cost resources.

Capsaicin, extracted from locally sourced Scotch Bonnet peppers (Capsicum chinense), was paired with methyl salicylate and co-encapsulated via gelatin–gum acacia complex coacervation into four distinct microcapsule populations of graded wall thickness (0.5:0.5 → 2:2). This architecture was deliberately engineered to create a staged, multi-phase release profile , thinner-walled populations providing rapid onset relief, while thicker-walled populations sustain action over extended periods. Encapsulation efficiency progressively improved from 52.7% to 60.4%, and drug loading remained consistently high at 429-479 mg g⁻¹ across all batches.

Comprehensive characterisation through FTIR, XRD, and GC-MS confirmed successful encapsulation, wall integrity, and amorphous drug dispersion within the polymer matrix ; all favourable for enhanced bioavailability. DPPH antioxidant and protein-denaturation anti-inflammatory assays further validated the retained bioactivity of the encapsulated actives.

All four microcapsule populations were incorporated into a thermosensitive Pluronic F-127 gel, which transitions from liquid to semi-solid at body temperature, offering a highly patient-friendly application experience. By simultaneously targeting TRPV1-mediated neuropathic and inflammatory pain through a single transdermal application, this system represents a meaningful step toward opioid-sparing, accessible pain management  directly supporting the United Nations Sustainable Development Goal 3 for good health and well-being.