Novel Analgesic Drug Eluting Soy Protein Films as Wound Dressings

Background: To this day, pain management of cutaneous wounds remains a challenge for field level care-givers to face. The currently available wound dressings do not treat pain, and therefore systematic administration of analgesics is required, resulting in relatively low drug concentrations at the wound site. In our study, soy protein is used as a base material for drug eluting wound dressings which are biocompatible, plant-based, relatively cheap and provide controlled release of analgesic agents locally to the wound site.

Methods: Different formulations of wound dressings loaded with bupivacaine, an analgesic agent, were prepared. Cytotoxicity of the films was tested on human fibroblasts using Alamar Blue assay. Drug release profiles were characterized using HPLC.

Results: Cytotoxicity tests indicate good viability for all film formulations tested, with no significant difference amongst the various bupivacaine concentrations. Moreover, even the highest drug concentration showed excellent viability. Drug release profiles showed rapid release during the initial 24 hours and a continuous slower release for up to 1 week.

Conclusions: Our results indicate a safe and controlled release of bupivacaine over a period of more than 24 hours. Modification of the film formulation allows to adjust bupivacaine release rate and therefore the duration of the analgesic effect. Our technology presents a new concept in the field of pain management, already at first response care.