Co-delivery of drugs by adhesive transdermal patches equipped with dissolving microneedles for the treatment of rheumatoid arthritis

In this study, a dosage form consisting of dissolving (D) microneedles (M) and an adhesive (A) transdermal patch (P; DMAP) was designed and pre-clinically evaluated for the treatment of rheumatoid arthritis (RA). The tip of the dissolving microneedles (DMNs) was loaded with the macromolecular drug melittin (Mel@DMNs), this to treat joint inflammation and bone damage, while the adhesive transdermal patches contained the low molecular weight drug diclofenac sodium (DS; DS@AP) for pain relief. Mel@DMNs and DS@AP were ingeniously connected through an isolation layer for compounding Mel-DS@DMAP for the simultaneous delivery of the drugs. In vitro and in vivo experiments showed that DS@AP did not affect the mechanical properties and dissolution process of Mel@DMNs while the pores formed by the microneedles promoted the skin penetration of DS. Treatment of rats suffering from RA with Mel-DS@DMAP reduced paw swelling and damage of the synovium, joint and cartilage, suggesting that the 'patch-microneedle' dosage form might be promising for the treatment and management of RA.

Automated summary

In this study, a novel dosage form consisting of dissolving microneedles and an adhesive transdermal patch was developed for the treatment of rheumatoid arthritis. In vitro and in vivo experiments demonstrated that the combination of drugs delivered by this dosage form effectively reduced joint inflammation and damage.