Study On The Optimization Of Prescription And Preparation Characteristics Of Ornidazole Injection

Aim:The aim of this project was to develop ornidazole injection with low content of propylene glycol and ethanol and good stability,so as to reduce the incidence of clinical side effects.To this end,we had established a new formulation of ornidazole anhydrous injection without propylene glycol and low ethanol concentration.The effect of moisture on the stability of the formulation was small,and in this prescription,ornidazole had high solubility and good stability.The preparation process of the new prescription was optimized,and then compared with the original ornidazole injection,including the preliminary study of pharmaceutical behavior in vivo and in vitro and the stability study,in order to obtain a stable,safe and effective new ornidazole injection.Methods:1.Prescription selection of new ornidazole injectionAccording to the original formulation of ornidazole injection and ornidazole injection in China,the dissolution system of ornidazole was divided into water system and non-water system.After the injections of the two systems were prepared,the properties of the injections,pH,and related substances were used as evaluation indicators to screen out a better ornidazole dissolution system.A UV spectrophotometric method for determining the content of ornidazole was established.By measuring the absorbance of ornidazole in different mixed solvents,the solubility of ornidazole was calculated,and the mixed solvent with the highest solubility of ornidazole was screened to reduce the amount of organic solvents.The goal was to determine the content of ornidazole and related substances through a 10-day high-humidity experiment,investigate the stability of ornidazole in different mixed solvents,and select the best mixed solvent that had a high solubility in ornidazole and was less affected by moisture.Ornidazole was dissolved in the best selected mixed solvent,and different volumes of ornidazole solution were prepared.The physical stability of each solution was investigated at4℃,so as to determine the specification volume of new ornidazole injection.2.Study on the preparation of neoornidazole injectionThe molecular weight of the related substances in ornidazole injection was determined by LC-MS,and the molecular structure of the related substances was confirmed with reference to the literature,providing the basis for the control of the related substances in the preparation process of new ornidazole injection.The water in ornidazole injection mainly came from the water in the prescription and the water introduced in the production and storage process.By adding different content of water to ornidazole injection,the content of ornidazole and related substances were determined to control the water content in a certain level.Taking pH value,content and related substances as evaluation indexes,the preparation process of ornidazole injection was optimized,including the selection of solution temperature,storage time after solution preparation,amount of activated carbon,treatment time of activated carbon and sterilization time,to explore the influence of different preparation processes on the stability of ornidazole injection.3.Stability of new ornidazole InjectionThe stability of new ornidazole injection was compared with that of original research ornidazole injection.Taking the properties,pH value,visible foreign matter,content and related substances as stability investigation items,the freeze-thaw test,high temperature test,high humidity test,light test,accelerated test and long-term test were used to study the stability differences between the two injections.4.Study on the compatible stability of neoornidazole injectionAccording to the administration route of original research orignazole injection,the injection should be diluted properly before application,and then intravenous drip.Taking the properties,pH value,visible foreign matters,content and related substances as evaluation indexes,the compatibility tests of new ornidazole injection and original research ornidazole injection with 0.9%NaCl injection,5%glucose injection and 10%glucose injection were carried out respectively.The differences of compatibility stability between the two injection were compared,and the best compatibility solvent was selected.5.Preliminary study of ornidazole in vivo and in vitro pharmaceutical behaviorCompared with the original research ornidazole injection,the pharmacological behavior of neoornidazole injection liquid was studied in vitro and in vitro.The in vitro pharmacological behavior of the two injections was investigated by in vitro release test,hemolysis and coagulation test.The pharmacokinetics of SD rats was used to study the in vivo pharmacological behavior of the two injections.Results:1.312nm was determined as the maximum absorption wavelength for determining the content of ornidazole,and the regression equation was determined by linear fitting with the concentration of ornidazole as the abscissa and the absorbance as the ordinate to obtain A=0.0522C-0.0842 and R²=0.9998.The system adaptability and repeatability test results showed that the method was feasible.Compared with the ornidazole water system,the non-aqueous system had a higher content of ornidazole and a lower content of related substances,so the non-aqueous system was selected as the ornidazole dissolution system.The results of solubility test showed that the solubility of ornidazole was the highest when the ratio of PEG400 ethanol,PEG600/ethanol,glycerin/ethanol and DMAC/ethanol were 3:2,4:1,3:2 and 3:2,respectively.Compared with other three mixed solvents,ornidazole had the highest solubility in PEG400/ethanol with a mixture ratio of 3:2.The results of high humidity test showed that the impurity content of ornidazole in PEG400/ethanol mixed solvent was the lowest and there was no significant increase compared with the other three mixed solvents,indicating that the stability of ornidazole in PEG400/ethanol mixed solvent was the highest.According to the results of solubility test and high humidity test,PEG400/ethanol with a mixture ratio of 3:2 was selected as the best mixed solvent for neoornidazole injection.According to the original specification of ornidazole injection（3m L:0.5g）,the fixed amount of ornidazole was 0.5g.When the volume of PEG400/ethanol solution of ornidazole was prepared into 1.5m L,the physical stability of the solution was good.Therefore,the standard volume of neoornidazole injection was 1.5m L.2.The molecular structure of three related substances in Ornidazole injection could be confirmed by LC-MS,which were 2-methyl-5-nitroimidazole and 1-（2’,3’-dihydroxypropyl）-2-methyl-5-nitroimidazole,1-（2’,3’-epoxypropyl）2-methyl-5-nitroimidazole.As the moisture content in the prescription increases,the impurity content of the homemade preparation and the original development agent would increase,but the impurity content and impurity growth rate of the homemade sample were lower than the original research sample.Therefore,the homemade preparation was less affected by the water and more stable than the original development agent.The experimental results of the introduction of trace moisture during the formulation process showed that the stability of neoonidazole injection was good when the moisture content was controlled to less than 1%.Taking the dissolution time,the content of the main drug and related substances as evaluation indicators,the solution temperature was selected to be 40℃,and the solution was stable within 8 hours of the solution preparation.Taking the pH value and the content of the main drug as the evaluation indicators,the amount of activated carbon was selected to be 0.1%and the activated carbon treatment time was 15minutes.Taking the pH value,main drug content and related substances as evaluation indicators,the sterilization time was screened for 15 minutes.3.The stability of the new ornidazole injection was compared with that of the original ornidazole injection.The two injections had good stability in low temperature freeze-thaw,light,acceleration and long-term experiment.Under the condition of high temperature,the related substances of the two injections increased slightly.After 10 days of high humidity,the total impurity content of the new ornidazole injection and the original ornidazole injection increased to 0.012%and 0.190%,respectively.The stability of the new ornidazole injection was better.4.When the new ornidazole injection and the original ornidazole injection were combined with 0.9%sodium chloride injection,5%glucose injection and 10%glucose injection respectively,the properties,visible foreign matters,ornidazole content and related substances of the solution met the requirements,and the pH value was stable.5.The results of in vitro release showed that the curves of in vitro release oforiginal ornidazole injection and new ornidazole injection were similar,and they could be released completely in a short time.The results of hemolysis and coacervation test in vitro showed that no hemolysis and coacervation were observed within 3 hours,indicating that ornidazole injection was safe.The HPLC method for the determination of ornidazole in plasma samples was verified by methodology,and the specificity,linearity,accuracy and precision were all in line with the requirements of biological sample analysis method.The elimination half-life t_1/2of original research and self-made ornidazole injection was 1.53±0.05 and 1.85±0.08μg/m L*h,the average residence time MRT_0-twas 1.98±0.16 and 2.55±0.18h,AUC_0-∞was 31.81±3.67and 42.33±2.58μg/m L*h,the clearance CLwas 0.63±0.06 and 0.47±0.03L/h/kg,and the apparent volume of distribution V was 1.39±0.15 and 1.26±0.12L/kg,respectively.Conclusion:Aiming at a series of clinical safety issues caused by the stability of the original research ornidazole injection affected by moisture and the large amount of organic solvent,through the prescription screening and preparation process optimization,a new ornidazole injection with better solubility to ornidazole,less water influence and less organic solvent consumption was obtained.Through stability test,it was shown that the new ornidazole injection was more stable than the original ornidazole injection.New ornidazole injection had no hemolysis and condensation in vitro,and its release in vitro was similar to that of original ornidazole injection.Compared with the original ornidazole injection,the concentration of ornidazole in the plasma of the new ornidazole injection was high and it was not easy to be removed,and the retention time in the body was long.Therefore,the new ornidazole injection had the advantages of good stability,small amount of organic solvent,long-lasting effect in vivo and potential to reduce clinical side effects.