nsense Ltd. is a specialty wound care company that has developed a range of novel active hydrogel-based dressings, OxyzymeT and IodozymeT, which are capable of active delivery of oxygen, iodine and nitric oxide to a wound site
This innovative dressing is composed of a hydrogel bi-layer containing an active enzyme (glucose oxidase) and a number of other components including glucose substrate. On activation of the dressing, a biochemical reaction is triggered leading to active delivery of oxygen into the wound (Oxyzyme™) and generation of antimicrobial iodine (Iodozyme™) that kills infections and facilitates the healing of chronic wounds.
Challenge
The wound dressing must be sterilised by gamma radiation and requires a minimum of 2 years shelf life at 25°C. In initial experiments, the activity of the enzyme in the wound dressing was completely lost after sterilisation by 25-40 kGy of gamma radiation. Similarly, the enzyme activity was rapidly lost in the aqueous environment of the hydrogel dressing during storage at 25°C in a formulation optimised by conventional means.
Without considerable stabilisation the product could never be commercialised.
A combination of Arestat-R™ and Arestat-T™ technology were used to stabilise the glucose oxidase in the aqueous environment of the hydrogel and provide a wound dressing with a commercially viable shelf- life. A combination of specific excipients were included in the formulation, combined with adjustments of other formulation parameters based on underlying scientific principles of the Arestat™ technology. Consequently, the glucose oxidase in the wound dressing retained almost full activity immediately following irradiation and upon subsequent storage.
The product has been approved as a Class III medical device in the EU and Canada, and is awaiting an approval in the US. It has been granted a shelf life of three years at ambient temperature. This was the first commercial application of Arecor’s stabilisation technology.
