Injectable thermosensitive lipo-hydrogels loaded with ropivacaine for prolonging local anesthesia

•Sustained local anesthetics system can improve the satisfaction of patient.•Poloxamer 407 can release drugs sustained but with higher initial burst release.•Ropivacaine loaded injectable liposome-in-gel had low initial burst release.•Ropivacaine loaded gel was useful for local anesthesia without systemic toxicity.