Establishment Of Quality Standard And Determining Methodology Of Eprinomectin Sustained-release Injection

Eprinomectin（EPR）is a member of the avermectin family and consists of a mixture of two similar molecules B1a and B1b.The EPR sustained-release injection has the advantages of less administration times and long efficacy time.This paper intends to establish the quality standard via studying the quality of self-developed EPR sustained-release injection.The thesis intends to establish quality standards via studying the quality of the self-released EPR sustained-release injection.The pharmaceutical equivalence of self-developed and original EPR sustained-release injection was studied through the dissolution of self-developed and original-developed sustained-release agents for injection.The effects of EPR sustained release injection on subcutaneous tissue and muscle tissue of Japanese white rabbits were studied via studying the subcutaneous and muscle irritation of EPR sustained release injection on Japanese white rabbits.A method for the determination of EPR in bovine serum by HPLC-FLD was established.This method has been proved to be suitable for the detection of EPR in bovine plasma.1.The appearance,viscosity,pH,moisture,density,endotoxin,content and related substances of the self-researched EPR sustained-release injection were detected.The chromatographic column of the content and related substances is Phenomenex Luna 5μ-C8-100A 250×4.60 mm 5 micron.The detection method was as followed:acetonitrile-0.1%aqueous perchloric acid solution with gradient.The results showed that the appearance of the self-developed EPR sustained-release injection was clear and transparent,the average relative viscosity was 46.45 m Pa?s,the average p H was 6.88,the preparation contained no water,the density was 1.13 g/cm³,the endotoxin met the limit of no more than0.1 EU/mg,the content was 1.03 times of the mark amount,and the amount of related substances was no more than 5%.The test results all met the requirements of the injection preparation.2.The pharmacoequivalence of the self-developed EPR sustained-release injection and the original EPR sustained-release injection was compared under the condition of 37℃with a speed of 50 r/min and 0.5%SDS in PBS buffer.The chromatographic column was ZORBAX Eclipse Plus C18 column（2.1 mm×50 mm,1.8μm）.The detection conditions were mobile phase:formic acid∶water∶acetonitrile（0.04 m L∶40 m L∶60 m L）,flow rate:0.4 m L/min,detection wavelength:245 nm,column temperature∶35℃,and injection volume∶2μL.After 31 days of release under the same condition,the cumulative release of both EPR sustained-release injections exceeded to 80%,and the similarity factor（f₂）between the self-researched and the original were greater than 50.3.The method of self-comparison between the left and right sides of the same body was adopted,subcutaneous and intramuscular injection of Japanese white rabbits.After conversion,the administration dose of EPR sustained-release injection was 0.131 m L/kg,and the same volume of 9mg/m L sodium chloride injection was used as the control.The results showed that,one week after subcutaneous injection,the EPR sustained-release injection had no obvious irritation to subcutaneous tissue.After intramuscular injection,the muscle was severely degenerated and necrotic.Pathological observation of muscle tissue showed obvious muscle necrosis,edema,inflammatory cell infiltration,obvious vascular hemorrhage,and the degree of injury is severe.4.The bovine serum added with EPR standard solution was pretreated,dried,derivatized and fixed volume,and the samples were detected by HPLC-FLD detector.The determination volume was a ZORBAX Eclipse Plus C18 column（2.1 mm×100 mm,1.8μm）.The detection conditions were mobile phase of formic acid:water:acetonitrile（0.01 m L:10 m L:90 m L）.The flow rate was 0.4 m L/min,the excitation wavelength was 365 nm,the detection wavelength was 463 nm,the column temperature was35℃,and the injection volume:20μL.The results showed that the method has high specificity,high recovery,and high stability.The method was suitable for the detection of EPR in bovine serum.In conclusion,the quality standards of EPR sustained-release injection according to the Veterinary Pharmacopoeia of the People’s Republic of China was established,and the self-developed EPR sustained-release injection had pharmacological equivalence.In irritant study,both self-developed and original EPR sustained-release injection for intramuscular injection had strong stimulating effects on the muscles of Japanese white rabbits and for subcutaneous injection no obvious irritation to subcutaneous tissue,so it is suitable for subcutaneous injection.The method for the detection of EPR in bovine serum had been proved to be suitable for the detection of EPR in bovine serum.