Transdermal Insulin Delivery Emphasizing on Microneedle Delivery System: A Review

People with type 1 diabetes require insulin therapy to control their blood glucose levels, and advanced type 2 diabetes patients frequently take it as well. The traditional method of delivering insulin is subcutaneous injection with a hypodermic needle or pump-mediated infusion, although these methods may cause pain, needle anxiety, poor adherence, and an increased risk of infection. Transdermal insulin administration has so been extensively researched as a desirable alternative to subcutaneous techniques for the management of diabetes in recent years. Transdermal methods that deliver controlled, continuous insulin release and limit insulin breakdown may be preferable for patients and improve adherence and glycemic results. Due to the protein drug's high molecular weight, passive insulin absorption via the skin is inefficient, which presents a problem for transdermal insulin delivery. In this review, we concentrate on the many transdermal insulin administration strategies, including chemically promoted, electrically enhanced, mechanical force-triggered, and microneedle-assisted ones, along with their corresponding benefits and drawbacks.