Background: Rheumatoid arthritis (RA) is a systemic autoimmune disease that significantly impacts the quality of life of those affected. Owing to the complex pathophysiology of RA, it is not possible for any singular treatment to entirely impede the progression of the disease. Hence, the current study aimed to adopt a holistic and synergistic approach towards the management of RA by means of a co-delivery strategy involving methotrexate (MTH), a conventional slow-acting anti-rheumatic drug, and baicalin (BCN), a bioactive phytochemical using a transethosomal (TRS) gel formulation.Purpose: The present study aims to evaluate the potential benefits of administering MTH and BCN in nanoparticulate form, which may lead to improved stability and solubility, as well as enhanced penetration into the arthritic tissues of interest.Methods and results: The MTH-BCN-TRS that were synthesised exhibited small particle size of 151.3 nm and polydispersity index of 0.125, as well as a favourable zeta potential of -32.22 mV. Additional assessments were conducted, including a pharmacokinetic analysis, TEM, skin permeation analysis and confocal microscopy. According to the Confocal laser scanning microscopy (CLSM) study, the formulated MTH-BCN-TRS gel exhibited superior MTH and BCN permeation through the skin layers when compared to the MTH-BCN suspension gel. The MTT experiment on Raw 264.7 and SW982 cell lines revealed a considerable reduction (p < .05) in the IC50 value of the MTH-BCN-TRS formulation (9.2 mM and 43.2 mM, respectively) in comparison to the drug suspension. According to the findings of the in vivo study, it was found that the MTH-BCN-TRS gel exhibits significantly promising anti-arthritic properties when compared to the conventional diclofenac gel. This was demonstrated through histopathological studies and radiographic analysis. Furthermore, skin irritation investigation on Wistar albino rats confirmed that the formulated MTH-BCN-TRS is a safe option for topical treatment on the skin. The present study has confirmed that the formulated TRS vesicles are a valuable carrier for the transdermal delivery of MTH and BCN, which may be used for the management of rheumatoid arthritis.
Keywords: Baicalin; Box–Behnken design; combinatorial nanomedicine; methotrexate; rheumatoid arthritis; transdermal delivery; transethosome.