title: Preparation and investigation of a novel levobupivacaine in situ implant gel for prolonged local anesthetics.
abstract: In this study, levobupivacaine (LBP) was successfully incorporated into implant application based on the concept of in situ gel (PECE). The physicochemical characterization (preparation, phase transition temperature, in vitro release) were investigated. The results of viscosity measurement showed that the preparations behaved like a fluid but formed a rigid gel when exposed to increasing temperature (37 °C). In vitro release, LBP was graduated released from the gels as time lapsed, suggesting that LBP was well entrapped in PECE in situ gels. As is shown in pharmacokinetic parameters, the half-life of LBP injection (2.7 h) was shorter than that of LBP in situ gels (23.9 h), suggesting that LBP injection was taken up by other tissues more rapidly than gels. The area under the curve of LBP in situ gels was 2.18 times the size of that of LBP injection (P< 0.05). In pharmacodynamic test, even after nine hours of injection, gel group could still maintain rather good anesthesia effect and rats' stinging reaction maintained at a relatively low level, which had obvious statistical differences compared to injection group.
authors.affiliation: a Department of Anesthesia , Shanghai Pulmonary Hospital, Tongji University of Medicine , Shanghai , China.
authors.forename: Yanjing
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: b Emergency Department , Xin Hua Hospital, Shanghai Jiao Tong University of Medicine , Shanghai , China.
authors.forename: Luocheng
authors.initials: L
authors.lastname: Zhou
authors.affiliation: a Department of Anesthesia , Shanghai Pulmonary Hospital, Tongji University of Medicine , Shanghai , China.
authors.forename: Ji
authors.initials: J
authors.lastname: Liu
authors.affiliation: a Department of Anesthesia , Shanghai Pulmonary Hospital, Tongji University of Medicine , Shanghai , China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: a Department of Anesthesia , Shanghai Pulmonary Hospital, Tongji University of Medicine , Shanghai , China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.affiliation: a Department of Anesthesia , Shanghai Pulmonary Hospital, Tongji University of Medicine , Shanghai , China.
authors.forename: Hong
authors.initials: H
authors.lastname: Shi
mesh_terms: D020341:Absorbable Implants; D000779:Anesthetics, Local / Q000097:blood / Q000493:pharmacokinetics*; D000818:Animals; D002045:Bupivacaine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D003692:Delayed-Action Preparations / Q000737:chemistry*; D065546:Drug Liberation; D005260:Female; D005782:Gels; D006168:Guinea Pigs; D006207:Half-Life; D007279:Injections, Subcutaneous; D000077554:Levobupivacaine; D008297:Male; D044367:Phase Transition; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013696:Temperature; D014783:Viscosity
chemical_list: D000779:Anesthetics, Local; D003692:Delayed-Action Preparations; D005782:Gels; D011091:Polyesters; C502908:poly(ethylene glycol)-poly(caprolactone)-poly(ethylene glycol); D011092:Polyethylene Glycols; D000077554:Levobupivacaine; D002045:Bupivacaine
keywords: Characterization; in situ gel; in vitro release; levobupivacaine; pharmacodynamics; pharmacokinetic