Glucosamine sulphate endorsed ibuprofen nanocrystals burdened polymeric gel demonstrated multidimensional anti-inflammatory and cartilage protective potential in experimental knee osteoarthritis: In vitro and in vivo studies

Osteoarthritis (OA) is a chronic degenerative musculoskeletal condition associated with progressive loss of hyaline cartilage, subchondral bone remodelling, and inflammation. Despite ongoing research, no United States Food and Drug administration (USFDA) approved drugs for OA are available. The current investigation explores the potential of glucosamine sulphate endorsed ibuprofen nanocrystals loaded polymeric gel (IBU-GS-NCs gel) for its anti-inflammatory and disease-modifying capabilities in the osteoarthritic rat model. IBU-GS-NCs were engineered by using the anti-solvent precipitation method that later exhibited particle size 34.57 ± 0.79 nm, zeta (ζ) potential −2.81 ± 0.6 mV, and drug content 7.05 ± 0.19 %. On the other hand, IBU-GS-NCs gel demonstrated 0.507 ± 0.029 % drug loading with spreadability and viscosity close to marketed diclofenac emulgel. Next, the amount of IBU infused through the rat skin in ex vivo permeation study from IBU-GS-NCs gel and IBU gel was calculated to be 479.59 ± 6.28 µg/cm² and 255.91 ± 4.44 µg/cm², respectively after 24 h with 1.87-fold increment. Steady-state flux and permeability coefficient for IBU-GS-NCs gel through rat skin were 31.70 ± 0.11 µg/cm²h and 63.41 ± 0.23×10^-3 cm/h, respectively. In contrast to the positive control, the representative radiograph for IBU-GS-NCs gel-treated osteoarthritic rats indicated regeneration of articular cartilage with the absence of osteophytes. Histological evaluation of IBU-GS-NCs gel illustrated marked recovery in articulate cartilage thickness as well as glycosaminoglycan (GAG) level. Western blot analysis for synovial tissue of positive control displayed a 9.01, 2.66, 2.51 and 5.75-fold increase in COX-2, TNF-α, and IL-1β, Col2a1 respectively as compared to normal control. In contrast, IBU-GS-NCs gel-treated rats demonstrated 6.28, 4.06, 2.81 and 5.54-fold reduction in COX-2, TNF-α, IL-1β, and Col2a1 respectively compared to positive control. These findings advocate for improved anti-inflammatory and cartilage protective potential of IBU-GS-NCs gel. In conclusion, IBU-GS-NCs gel may be a potential candidate for translating into a clinically viable product to offer effective treatment for knee OA.