Dissolving microneedles in transdermal drug delivery: A critical analysis of limitations and translation challenges.

Microneedles (MNs) have emerged as an innovative approach for transdermal drug delivery, offering an efficient and minimally invasive alternative to conventional injections and oral delivery systems. While their potential has been widely recognized and extensively studied, the translation of MN technology into clinical practice remains limited. Despite the vast amount of published research, much of it involves over-complexification without addressing the core barriers to practical application. For example, dissolving/degradable MNs face key limitations such as poor drug loading capacity, low dosing consistency, and challenges in delivering effective therapeutic concentrations. These constraints restrict their utility to niche applications, such as vaccination or delivering potent drugs that require minimal doses. Additionally, the lack of standardized quality control measures, the complex manufacturing processes, and the high costs associated specifically with sterile/aseptic production further impede clinical translation. Regulatory frameworks for MNs remain vague, slowing the development of products that meet approval standards. This review critically examines the fundamental barriers to dissolving/degradable MN commercialization, as the most studied type of MN, while exploring promising strategies to overcome them. Advances in formulation science, fabrication techniques, and material engineering have demonstrated potential in enhancing drug loading efficiency and delivery consistency. Moreover, the establishment of clearer regulatory guidelines and scalable production strategies could significantly accelerate the commercialization of MN technology. By shifting focus toward pragmatic and clinically relevant solutions, this review aims to bridge the gap between research innovations and real-world applications, paving the way for broader implementation of MN technology in medicine.