From co-delivery to synergistic anti-inflammatory effect: Studies on chitosan-stabilized Janus emulsions having chloroquine phosphate and flavopiridol in Complete Freund's Adjuvant induced arthritis rat model

For the first time, the co-delivery of chloroquine phosphate and flavopiridol by intra-articular route was achieved to provide local joint targeting in Complete Freund's Adjuvant-induced arthritis rat model. The presence of paired-bean structure onto the dispersed oil droplets of o/w nanosized emulsions allows efficient entrapment of two drugs (85.86–96.22 %). The dual drug-loaded emulsions displayed a differential in vitro drug release behavior, near normal cell viability in MTT assay, better cell uptake (internalization) and better reducing effect of mean immunofluorescence intensity of inflammatory proteins such as NF-κB and iNOS at in vitro RAW264.7 macrophage cell line. The radiographical study, ELISA test, RT-PCR study and H & E staining also indicated a reduction in joint tissue swelling, IL-6 and TNF-α levels diminution, fold change diminution in the mRNA expressions for NF-κB, IL-1β, IL-6 and PGE2 and maintenance of near normal histology at bone cartilage interface respectively. The results of metabolomic pathway analysis performed by LC-MS/MS method using the rat blood (plasma) collected from disease control and dual drug-loaded emulsions treatment groups revealed a new follow-up study to understand not only the disease progression but also the formulation therapeutic efficacy assessment.