# A novel anti-pruritic: Topical co-administration of high molecular weight hyaluronan (HMWH) with protamine, a transdermal transport enhancer

## TL;DR

A new topical treatment combining hyaluronan and protamine effectively reduces itching in rats by targeting itch-sensing neurons.

## Contribution

The study introduces a novel anti-pruritic formulation using HMWH and protamine for topical application.

## Key findings

- Topical HMWH with protamine significantly reduced scratching behavior in rats induced by serotonin.
- The formulation effectively reverses pruriceptor sensitization associated with itch.
- The treatment shows potential for both inflammatory and neuropathic itch conditions.

## Abstract

Pruritis, the sensation of itch, is produced by multiple substances, exogenous and endogenous, that sensitizes specialized sensory neurons (pruriceptors and pruri-nociceptors). Unfortunately, many patients with acute and chronic pruritis obtain only partial relief when treated with currently available treatment modalities. We recently demonstrated that the topical application of high molecular weight hyaluronan (HMWH), when combined with vehicles containing transdermal transport enhancers, produce potent long-lasting reversal of nociceptor sensitization associated with inflammatory and neuropathic pain. In the present experiments we tested the hypothesis that the topical formulation of HMWH with protamine, a transdermal transport enhancer, can also attenuate pruritis. We report that this topical formulation of HMWH markedly attenuates scratching behavior at the nape of the neck induced by serotonin (5-hydroxytryptamine, 5-HT), in male and female rats. Our results support the hypothesis that topical HMWH in a transdermal transport enhancer vehicle is a strong anti-pruritic.