The Journal of pharmacy and pharmacology
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J. Pharm. Pharmacol. · Nov 2008
Comparative StudyPharmacological and local toxicity studies of a liposomal formulation for the novel local anaesthetic ropivacaine.
This study reports an investigation of the pharmacological activity, cytotoxicity and local effects of a liposomal formulation of the novel local anaesthetic ropivacaine (RVC) compared with its plain solution. RVC was encapsulated into large unilamellar vesicles (LUVs) composed of egg phosphatidylcholine, cholesterol and alpha-tocopherol (4:3:0.07, mole %). Particle size, partition coefficient determination and in-vitro release studies were used to characterize the encapsulation process. ⋯ Treatment with RVC(LUV) increased the duration (P < 0.001) and intensity of the analgesic effects either on sciatic nerve blockade (1.4-1.6 fold) and infraorbital nerve blockade tests (1.5 fold), in relation to RVC(PLAIN). Regarding histological analysis, no morphological tissue changes were detected in the area of injection and sparse inflammatory cells were observed in only one of the animals treated with RVC(PLAIN) or RVC(luv) at 0.5%. Despite the differences between these preclinical studies and clinical conditions, we suggest RVC(LUV) as a potential new formulation, since RVC is a new and safe local anaesthetic agent.