UKZN scientists develop insulin skin patch

IN 2010, UKZN’s Prof Cephas Musabayane and Mark Tufts reported the discovery of a new method to administer insulin into the bloodstream via a skin patch. Hailed as an innovative finding, Musabayane and his team have now built on the previous study and have reported the development of insulin-containing dermal patches capable of sustained controlled delivery of insulin into the bloodstream.

The study, conducted by scientists in UKZN’s Discipline of Human Physiology with Prof Musabayane as principle investigator, was designed to establish whether application of pectin insulin-containing dermal patches sustain controlled release of insulin into the bloodstream of streptozotocin (STZ) induced diabetic rats as well as alleviate some diabetic symptoms.

The scientists found that after five weeks of daily treatment with insulin-containing dermal patches, neither inflammation nor necrosis was detected in the skin of the rats. The density of phosphorylated insulin receptor substrates (IRS) in skin tissues by immunohistochemical staining was also investigated. It was found that the widespread localization of IRS in cell bodies of the dermis, collagen and subcutaneous layer evoked by PI-containing dermal patches suggested that the pectin hydrogel insulin patch has the potential to deliver insulin across the skin and into the blood stream.

The findings are of considerable importance because application of insulin-containing dermal patches would free diabetic patients from daily bolus injections needed to maintain a constant insulin concentration. The pectin insulin (PI)-containing dermal hydrogel matrix patch would also provide patients with pain-free self-administration of insulin thereby improving compliance.

Musabayane said: “A PI hydrogel matrix patch formulation will be easy to use and will not require elaborative devices to prevent drug leakage as in solution formulations. The pectin hydrogel matrix cocktail comprised of low methoxy (LM) pectin gelled with calcium ions, insulin, a transdermal transfer enhancing agent and an antioxidant. The patch concoction did not show any detrimental effects on the morphology of underlying tissues of the skin as evidenced from histological observations.”

He said he believed the findings were significant and paved the way for diabetic patients to control their insulin levels in a pain-free manner with reduced negative side effects.

“The pectin insulin-containing dermal patches delivered physiologically relevant amounts of pharmacologically active insulin,” he said.