Modulation of Anti-Inflammatory Activity via Diclofenac Sodium-Based Nanostructured-Lipid Carriers: Physical Characterization and <i>In Vivo</i> Assessment.

<i>Diclofenac sodium (DS) is categorized under the nonsteroidal anti-inflammatory class of drugs that also belongs to biopharmaceutical classification system (BCS) class II. It has limited dissolution parameters which also resist the total bioavailability but it has a good transdermal permeability characteristic and the pharmacokinetic parameters of DS make it suitable for the formulation of nanostructured-lipid carrier (NLC)-based gel transdermal delivery. The research aimed to design and develop a drug-delivery system (DDS), i.e., DS-NLCs incorporated in gel to modulate its anti-inflammatory action via skin. The formulation was optimized using Taguchi's approach and the resultant NLCs were thoroughly characterized, including assessments for zeta potential, particle size, and morphological evaluation. Furthermore, particular investigations were carried out for DS-NLCs, including drug encapsulation efficiency, <i>ex vivo</i> release properties in Phosphate Buffer Saline at pH 7.4, and an <i>in vivo</i> skin irritation test. DS-NLCs had a mean size of 339 ± 25 nm and were spherical-shaped particles. With an encapsulation effectiveness of 84%, the NLCs were found to have effectively loaded drugs. Moreover, these NLCs demonstrated a sustained release characteristic that persisted for a maximum of 24 h, suggesting their potential for gradual and regulated drug release. Lipid components demonstrated good stability over 90 days and were biocompatible with the DS. Furthermore, compared with the usual formulation, topical gel loaded with NLC (GNLC) containing DS considerably suppresses edema in the <i>in vivo</i> result, suggesting that the developed formulation has superior anti-inflammatory efficacy. These NLCs provide prolonged release and better drug solubility, both of which boost therapeutic outcomes and control the drug's anti-inflammatory potential. The study's conclusion emphasizes DS-NLC's potential as a cutting edge and effective medication delivery technology. The results indicate the need for more preclinical research, which presents an effective direction for developing a more potent and well-tolerated therapeutic strategy.</i>