Microneedle- based drug delivery systems: challenges and future perspectives

Microneedle (MN)-based drug delivery systems have emerged as a promising approach for transdermal drug administration by overcoming the barrier function of the stratum corneum. These minimally invasive systems offer several advantages, including improved drug permeation, reduced pain, enhanced patient compliance, and the potential for controlled drug release. This review discusses the classification of microneedles, including solid, coated, dissolving, hollow, and hydrogel-forming systems, along with their mechanisms of drug delivery. Various materials, such as metals, silicon, and biodegradable polymers, and fabrication techniques, including micromoulding, photolithography, and three-dimensional (3D) printing, are also explored. Furthermore, the review highlights important characterization parameters and pharmaceutical applications in vaccination, diabetes management, dermatological treatment, wound healing, cancer therapy, and biosensing. Recent innovations, including stimuli-responsive microneedles, bioinspired designs, wearable sensing devices, and personalized drug delivery platforms, may further expand their therapeutic potential. Despite these advances, challenges related to mechanical strength, drug loading, stability, dose accuracy, manufacturing scale-up, sterility, patient acceptability, and regulatory requirements remain. Overall, microneedle technology represents a promising platform for advanced drug delivery; however, further research, standardized evaluation, and clinical studies are necessary to establish its safety, efficacy, and successful commercial translation.