Study Of Preparation Of Praziquantel Emulsive Diluents For Rabies Vaccine

Rabies and some taeniasis, for instance cystic echinococcosis (CE), are important zoonoses of livestock and humans, and they affect livestock production seriously and also threaten public health. The dog is the main infective sources of the rabies, whilst it also acts as the definitive host of CE. Hence, it will probably have great clinical practical significance to develop a compound preparation of rabies vaccine and anthelmintics of tapeworms, with which we could achieve the goals of controlling rabies by immuning and deworming the tapeworms, especially for CE, at the same time. Therefore, on the basis of previous work, the compound preparation of praziquantel emulsive diluent for rabies vaccine was further studied and improved.First of all, in order to investigate the carrying rates of rabies virus and tapeworms in stray dogs, we checked the rabies antigens and dog tapeworm infection status in Hohhot. The results showed that the carrying rate of rabies virus in the stray dog was 13.4%, while the tapeworm infection rate was 52.6%.Secondly, in order to solve the problem that the vaccine is water soluble but praziquantel can only be dissolved in organic solvents, the emulgator, antifreeze and viscosity regulator were screened, and their contents were determined. The stable praziquantel water emulsion was successfully prepared, then the preparation technique was also optimized by response surface method. Later, we analyzed the praziquantel water emulsion quality, and the results showed that praziquantel concertration is 20±0.02mg/mL. The stability of compound preparation was good, and it met the various requirements of the product.Furthermore, we have tested the stability, pharmacokinetics and toxicity of the compound preparation of rabies vaccine and praziquantel aqueous diluent. The results revealed that the plasma concentration of the compound preparation could reach peak 120 min post drug injection, and its median lethal dose (LD50) was 232mg/kg. The stimulation test proved that there was little irritation to the animals and no damage to the liver and kidney of the animals.The results from clinical trials showed that the worm reduction rate was 92.8%, while the rabies antibodies producting rate was 89.3%. Those proved that the compound preparation could prevent rabies and deworm tapeworms at the same time.