Chitosan coated clove oil-based nanoemulsion: An attractive option for oral delivery of leflunomide in rheumatoid arthritis

Rheumatoid arthritis (RA), a distressing inflammatory autoimmune disease, is managed mainly by Diseasemodifying antirheumatic drugs (DMARDs), e.g. leflunomide (LEF). LEF (BCS class II) has limited solubility and adverse effects following its systemic exposure. The appealing antirheumatic properties of both clove oil and chitosan (CS) were exploited to design oral leflunomide (LEF)-loaded nanoemulsion (NE) system to augment the therapeutic action of LEF and decrease its systemic side effects as well. Different LEF-NEs were prepared using clove oil, Tween & REG; 20 (surfactant), and PEG 400(co-surfactant) and characterized by thermodynamic stability, percentage transmittance, cloud point, size analysis, and drug content. Optimized LEF-NE was subjected to CS coating forming LEF-CS-NE that exhibited nanometric size range, prolonged drug release, and good physical stability. In vivo anti-rheumatic activity of pure LEF, market LEF, and LEF-CS-NE was assessed utilizing a complete Freund's adjuvant (CFA) rat model. Treatment with LEF-CS-NE reduced edema rate (48.68% inhibition) and caused a marked reduction in interleukin-6 (IL-6) (510.9 & PLUSMN; 2.48 pg/ml), tumor necrosis factor- & alpha; (TNF-& alpha;) (397.3 & PLUSMN; 2.53 pg/ml), and rheumatoid factor (RF) (42.58 & PLUSMN; 0.49 U/ml). Furthermore, LEF-CS-NE reduced serum levels of glutamic pyruvic transaminase (GPT) to (83.19%) and glutamic oxaloacetic transaminase (GOT) to (40.68%) compared to the control + ve group. The effects of LEF-CS-NE were also superior to both pure and market LEF and showed better results in histopathological studies of paws, liver, kidney, lung, and heart. The remarkable therapeutic and safety profile of LEF-CS-NE makes it a potential oral system for the management of RA.