Research progress on the application of microneedle transdermal drug delivery system in dermatology

Transdermal drug delivery systems(TDDs)have the advantages on good local targeting,controlled and sustainable drug delivery.Hoewever,the stratum corneum,as the main skin barrier,severely limits the transdermal penetration of drugs and reduces bioavailability,which also limits their application.Microneedles(MNS)penetrate the stratum corneum and create several reversible microchannels in a minimally invasive manner to significantly improve the penetration of therapeutic agents,and are considered a milestone for effective transdermal drug delivery.As an emerging drug delivery modality,microneedle transdermal drug delivery systems have the advantages of being minimally invasive,safe,efficient,economical and convenient.In addition to the extensive research on microneedles for improving transdermal drug delivery,there is a growing interest in using them to manage and treat dermatological conditions.Being the largest organ in the human body,the skin acts as a barrier between the body and the external environment,while having an immense influence on appearance and self-confidence.Indeed,there is now a considerable body of evidence on how dermatological conditions can lead to psychological problems and a reduced quality of life.The utilisation of microneedle transdermal drug delivery systems for the management and treatment of dermatological conditions is of great therapeutic and commercial value.The principleof microneedle transdermal drug delivery systems and the progress of its clinical application in dermatology are reviewed here.

Applications and recent advances in transdermal drug delivery systems for the treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic,systemic autoimmune disease predominantly based on joint lesions with an extremely high disability and deformity rate.Several drugs have been used for the treatment of rheumatoid arthritis,but their use is limited by suboptimal bioavailability,serious adverse effects,and nonnegligible first-pass effects.In contrast,transdermal drug delivery systems(TDDSs)can avoid these drawbacks and improve patient compliance,making them a promising option for the treatment of rheumatoid arthritis(RA).Of course,TDDSs also face unique challenges,as the physiological barrier of the skin makes drug delivery somewhat limited.To overcome this barrier and maximize drug delivery efficiency,TDDSs have evolved in terms of the principle of transdermal facilitation and transdermal facilitation technology,and different generations of TDDSs have been derived,which have significantly improved transdermal efficiency and even achieved individualized controlled drug delivery.In this review,we summarize the different generations of transdermal drug delivery systems,the corresponding transdermal strategies,and their applications in the treatment of RA.

Expert consensus of the Chinese Association for the Study of Pain on pain treatment with the transdermal patch

Chronic pain lasting more than 3 mo,or even several years can lead to disability.Treating chronic pain safely and effectively is a critical challenge faced by clinicians.Because administration of analgesics through oral,intravenous or intramuscular routes is not satisfactory,research toward percutaneous delivery has gained interest.The transdermal patch is one such percutaneous delivery system that can deliver drugs through the skin and capillaries at a certain rate to achieve a systemic or local therapeutic effect in the affected area.It has many advantages including ease of administration and hepatic first pass metabolism avoidance as well as controlling drug delivery,which reduces the dose frequency and side effects.If not required,then the patch can be removed from the skin immediately.The scopolamine patch was the first transdermal patch to be approved for the treatment of motion sickness by the Food and Drug Administration in 1979.From then on,the transdermal patch has been widely used to treat many diseases.To date,no guidelines or consensus are available on the use of analgesic drugs through transdermal delivery.The pain branch of the Chinese Medical Association,after meeting and discussing with experts and based on clinical evidence,developed a consensus for promoting and regulating standard use of transdermal patches containing analgesic drugs.