Study On The Preparation For Decoquinate Solid Dispersion And Its Effect Against Rabbit Coccidia

Rabbit coccidiosis is one of the most common and serious disease in rabbitindustry. It not only affects the production performance of rabbits, but also reduces orloses the value of rabbit as an experimental animal, thus to cause huge economic lossesto the rabbitry every year. Decoquinate as a new low toxicity and broad-spectrumanticoccidial drugs is almost insoluble in water. Currently, its dosage form in clinicalapplication in domestic and international is mainly for premix, but decoquinate premixis not convenient, clinical mixed feeding is uneven. The feed intake of livestock byEimeria infection decreased and limited the use of decoquinate, thereby affecting drugabsorption. During the feed additive production process, the drug composition, structureand other properties will be affected by high temperature and other factors on theanticoccidial effect. So solid dispersion technique is used to overcome the defect of thepoor hydrophilicity and not easily dispersed in water of decoquinate in this study. It cansolve the limited problem that decoquinate cannot be used in drinking water and greatlyincrease the range of clinical application. It is convenient to product, store and transportand use. It is expected to provide an exact curative effect, convenient use, high qualitynew anticoccidial drugs to farmers, to meet the urgent needs of breeding industry.In this study, decoquinate-PEG6000solid dispersant by the melting method wasprepared under the conditions of different proportions with surfactant dispersant andwithout it. The raw material drug, solid dispersant, physical mixture of decoquinate wascompared in vitro dissolution test. The result showed the dissolution of solid dispersantin different proportion and preparation methods had greatly improved compared withraw material medicine. Decoquinate-PEG6000solid dispersant in the dissolution hadgradually increased with the proportion of the carrier. Decoquinate-PEG6000-SDS soliddispersant with the proportion of the carrier increasing, the dissolution speeded up andthe dissolution in1:6:2had the most significant effect. Its vitro dissolution at60minwas29.8%, the corresponding physical mixture was10.45%, but the dissolution in1:8:2decreased insteadly. It indicated the addition of surfactant was helpful to improve thedissolution. So decoquinate-PEG6000-SDS in1:6:2was chose as the best preparation process. The stability study on solid dispersant in aqueous solution showed its goodstability. The preliminary stability in accelerated test showed the drug was basicallystable under the relative humidity of75±5%, room temperature and37°C, but someslight melting appeared under55°C and its content obviously decreased. After repeatedmeasurement, the percentage was determined as3.95%.To synthesize some indexes such as clinical symptoms, necropsy observation andintestinal lesions score, body weight gain, decrement of coccidia oocyst, decoquinatesolid dispersant and mixing raw material drug showed different degrees of anticoccidialactivity. The anticoccidial efficacy of toltrazuril group and were better than decoquinatemixture and solid dispersant groups. The anticoccidial efficacy of toltrazuril group wasthe best. Decoquinate solid dispersant could be used as a preventive anticoccidial drugsadministered into drinking water to match with mixture on anticoccidial level andanticoccidial effect was good so as to simplify the mode of administration. Preliminaryview is that changing the formulations of decoquinate to achieve the desired effect ofanticoccidial is feasible and can meet the need of production.To sum up, the study can provide some references and basis for decoquinate soliddispersant in preparation and anticoccidial efficacy.