ABSTRACT
Insulin is a therapeutic protein widely used for diabetes mellitus management, being used as insulin replacement in Type 1 diabetes mellitus (T1DM) patients or adjuvant of oral antidiabetic agents in Type 2 diabetes mellitus (T2DM). It is preferably administered by subcutaneous (SC) injection because of limited pharmacokinetics (PK), especially due to low absorption caused by high molecular weight and hydrophilicity. However, the big challenge of achieving a worthy bioavailability (BA) through noninvasive formulations remains. It is crucial that a new insulin delivery system presents a BA high enough to overcome the bias related to an unconventional therapeutic compared to a well-established route of administration, such as SC insulin injection. The noninvasive method offers continuous and pulsatile drug delivery, being able to be combined with microneedles in order to have a synergic effect for insulin delivery as described in an in vitro and in vivo study published by Chen et al.
