The Study Of Encapsulated Cysteamine Release Evaluation With Gastric-small Intestine Simulated Digestion

Cysteamine hydrochloride?CSH?can promote the growth of animals by changing the disulfide bond of somatostatin.Due to its special physical and chemical properties,it is applied in the form of an enteric encapsulated.The release efficay in the digestive tract is generally evaluated by animal growth performance,which is time consuming and laborious.This experient aimed to evaluate the encapsulate effect of encapsulated cysteamine products by simulated gastric-small intestinal digestion,and to examine the effect of the encapsulated product on the growth performance of the broiler to validate the evaluation with simulated digestion.The objective was to establish a method to evaluate the release of the encapsulated product in the gastric-small intestine,which would provide reference for the improvement of the encapsulated technology and the quality control of encapsulated product for the enterprise.This experiment was divided into 4 parts.1)This experiment was conducted to improve the iodimetry for determination of CSH in diet,digesta,and excreta.2)Experiment 2 was conducted to establish HPLC-MS with pre-column derivatization for the determination of CSH concentration in digesta and excreta of rooster.N-ethylmaleimide was used as a derivatizing agent,and the separation was performed with C18 column.The mobile phases were acetonitrile?containing 0.1%formic acid?and water?containing 0.1%formic acid?.3)Experiment 3 was to evaluate the releasing process of 2 types of encapsulated CSH in simulated gastro-intestinal digestion for rooster.A single-factor completely randomized design was adopted to evaluate the releasing process of CSH.There were 4 levels of simulated gastric digestion time and 4levels of simulated small intestine digestion time.The release rate of encapsulated CSH in the simulated digestion was determined.In addition,the residues of the encapsulated products before and after simulated digestion were observed under a microscope to investigate the appearance change of encapsulated products during the release process.4)A single factor randomized block design was arranged with 6 replicates of 4 treatment.Each replicate contained 16 broilers.The first treatment was basal diet.Treatments 2,3or 4 were basal diet added 80mg/kg of type?encapsulated product,40mg/kg of type?encapsulated product or 80mg/kg of type?encapsulated product.It was conducted to validate the results of experiment 3 by comparison of the effect 2 encapsulated products on the growth performance of broilers.Results:1)The pretreatment with an appropriate amount of H₂SO₄ solution can improve the determination of CSH by eliminating the interference from diet,digesta or excreta.2)When determining the content of CSH in duodenal digesta,jejunal digesta and excreta by HPLC-MS,the recoveries of CSH was above 90%.In conclusion,the content of CSH in digesta and excreta can be determinated accurately by pre-column derivatization liquid chromatography.3)The release rates of type I encapsulated CSH product in gastric simulated digestion and small intestine simulated digestion was about5%and 20%,respectively.In addition,the release rates of type?encapsulated product in the gastric simulated digestion was about 72%,moreover,the CSH in type?encapsulated product can be completely released in the small intestinal simulated digestion.4)The average daily gain,21-day-old weight of the treatment 3 and 4 were significantly higher than those of the treatment 1?P<0.05?,especially in the treatment 3;A significant improvement of growth performance of broilers was not observed in treatment 2,which may be related to incomplete release of the type I encapsulated CSH product observed in experiment 3.In summary,this study established methods for the determination of CSH content in the background of digesta,and excreta.On this basis,the release characteristics of encapsulated CSH products were evaluated by gastro-small intestinal simulated digestion.In addition,the release results were validated by broiler growth performance,which would provide reference for the improvement of the encapsulated technology and the quality control of encapsulated product for the enterprise.