Topically applied opioids are an option to induce efficient analgesia in patients with severe skin wounds. For ongoing pain reduction, the vehicle should provide sustained drug release in order to increase the intervals during the regular wound dressing changes. In addition, the formulation should not impair wound healing. Hydrogels provide a moist wound environment, which is known to facilitate the healing process.
Methods and results
Investigating poloxamer hydrogels as a carrier system for morphine in terms of release behavior and (per-)cutaneous absorption, poloxamer 407 25 wt.% hydrogel sustained morphine release up to 24 h. The drug release rate decreased with increasing concentration of the gel forming triblock copolymer. Poloxamer 407 25 wt.% hydrogel retarded morphine uptake into reconstructed human skin and percutaneous drug absorption compared to a hydroxyethyl cellulose reference gel.
The results of our in vitro study indicate that the thermosensitive poloxamer 407 25 wt.% hydrogel is an appropriate carrier system for the topical application of morphine with regard to sustained drug release and ongoing analgesia.