02 February 2018

Inhale enkephalin

Opioid painkillers were suggested to be replaced with a nasal spray

Natalia Pelezneva, Naked Science

A group of British and American researchers have proposed an alternative to traditional forms of opioid analgesics. The analgesic component is the opioid peptide ley-enkephalin, "packed" in microscopic capsules made of a decomposable polymer. The polymer protects the substance from destruction, allowing it to reach the patient's brain. Scientists plan to test the drug on a group of healthy volunteers.

Ley-enkephalin is an endogenous opioid peptide, it is present in the brain of many mammals, including humans. Its function is not completely clear: it is believed that it can soften the perception of pain and regulate intestinal activity. Researchers have suggested that ley-enkephalin will cause a lower degree of addiction than the usual opioid analgesics.

Although enkephalins have an analgesic effect, it is difficult to use them as analgesics, these components are effective only in the brain itself. Getting into the bloodstream with an injection, enkephalins are destroyed faster than they manage to get into the brain. The form of tablets is also not suitable: due to the "first pass effect" (first pass effect), the effectiveness of the drug may fall even before the drug enters the bloodstream. This happens when the drug is rapidly destroyed in the liver. To avoid this, the researchers suggested "packing" the drug into nasal spray microcapsules. Passing quickly through the nasal passages, the capsules are exposed to less aggressive effects. The shell was made of decomposable polymer GCPQ.

Leu-enkephalin.jpg

The spray was tested on laboratory rats. The pain level was measured using the hot plate test method, in which the animal is placed on a uniformly heated plate, and an estesiometer – an instrument that determines the degree of skin sensitivity. Scientists have found out that the analgesic spray successfully and quickly relieves pain. At the same time, the drug did not cause addiction in animals – the behavior of rats receiving the spray was compared with a group of animals receiving morphine.  

Researchers believe that this form will help prevent the development of addiction and reduce the number of overdoses. Scientists plan to test the drug on humans, healthy volunteers will become participants in the trials. If the study is successful, the method will be offered to people suffering from "breakthroughs" of severe pain – for example, cancer patients.

The study was published in the Journal of Controlled Release (Godfrey et al., Nanoparticulate peptide delivery exclusively to the brain produces tolerance free analgesia).

Portal "Eternal youth" http://vechnayamolodost.ru


Found a typo? Select it and press ctrl + enter Print version