Pharmacokinetic study of novel drug delivery systems for insulin administration in diabetic patients

Abstract

Diabetes requires constant insulin delivery systems, but the current methods like subcutaneous injections and insulin pumps are not ideal as they are slow and have erratic absorption profiles. Other newer forms of insulins that have been developed are oral insulin, trans-dermal insulin, insulin inhaler, and implantable insulin delivery systems; all of which have the aim of enhancing the pharmacokinetics of insulin. In this paper, these new delivery systems were compared with the conventional delivery systems based on bioavailability, onset of action, and patient compliance, and the idea of gene therapy was also presented as a revolutionary concept. The research was a four-arm, randomized crossover clinical trial on 50 diabetic patients with 30 Type 1 and 20 Type 2 patients where the patients were administered subcutaneous injections, microneedle patches, oral insulin capsules, and inhalable insulin in a cross-over design with wash-out periods. The study showed that all the novel systems improved the bioavailability and the absorption rates and of all the systems inhaled insulin was the fastest acting with the (Tmax 0. Microneedle patches were also effective; however, conventional injections provided better glycaemic control and longer durability. In the future, it is possible to reduce or even exclude the external insulin requirement due to gene therapy, in other words, modification of patient cells to produce insulin. From these findings, we can conclude that although new systems have considerable benefits gene therapy might be the direction for long-term diabetes management.