STUDY　ON　PRAZIQUANTEL　SUSTAINED　RELEASE PREPARATIONS　IN　CANINE　ECHINOCOCCOSIS

Tian　Guangfu,Liu　Jinfeng,Jia　Wanzhong,Liu　Bailin,Liu　Wei,Zhang　Jun(Lanzhou　Veterinary　Institute,CAAS,Lanzhou 730046)

Echinococcosis,Dog,Praziquantel　sustained　release　preparation,PHLPC

n　this　paper,4　kinds　of　antiechinococcosis　sustained　release　preparations　were　investigated　in　our　laboratory.The　experimental　infection　indicated　that　praziquantel　sustained　release　implant　No.3(PSRI　No.3)which　contained　about　1.5　gram　praziquantel　in　three　capsules　had　98.46%　and　97.72%　protection　rate(P<0.01)7　and　8　month　post　implantation　respectively.38　out　of　133　dogs　in　pilot　area　were　examinated　with　an　arecoline　purgation　method,and　they　had　no　worm　burden　of　Echinococcus　granulosus　8　or　14　month　post　implantation　while　control　dogs　had　20%　infection　rate(P<0.05).At　the　same　time,the　praziquantel　concentrations　in　the　blood　of　dogs　were　measured　with　reverse　high　performance　liquid　chromatography.The　average　praziquantel　content　in　the　blood　of　dogs　was　0.81μg/ml　from　1　to　7　month　after　being　given　PSRI　No.3,0.12　μg/ml　1　to　6　month　after　being　given　praziquantel　sustained　release　injection　No.3(PSRInj　No.3)and　1.18　μg/ml　1　to　8　hour　after　being　given　the　conventional　pesticide　dose　of　praziquantel　orally.These　results　showed　that　the　blood　praziquantel　concentration　of　dogs　given　PSRI　No.3　was　as　2/3　as　that　of　dogs　taking　the　standard　dose　orally,and　that　PSRI　No.3　had　97.72%　prophylaxis　rate.On　the　other　hand,the　concentration　of　dogs　given　PSRInj　No.3　was　only　as　10.17%　as　that　of　dogs　taking　the　oral　dose,and　PSRInj　No.3　had　55.65～65.11%　prophylaxis　rate.These　results　have　confirmed　that　PSRI　No.3　have　a　strong　efficacy　for　dogs　against　E.granulosus　infection.