49 results about "Drug Impurity" patented technology

The invention provides a preparation method for an N-nitrosamine genotoxic impurity of varenicline tartrate. The preparation method comprises the following steps: with ammonium formate as a hydrogen donor, carrying out reduction reaction on dinitrate under the catalysis of palladium carbon to obtain a diamino compound, carrying out a cyclization reaction on the diamino compound and an aqueous glyoxal solution to obtain a cyclization product, carrying out a hydrolysis reaction on the cyclization product under the action of sodium hydroxide, removing trifluoroacetyl to obtain free alkali, and finally, subjecting the free alkali to reacting with sodium nitrite under the catalysis of protonic acid to obtain the N-nitrosamine impurity. According to the invention, the technical vacancy of preparation methods for the impurity at present is filled in, the prepared high-purity impurity can be applied as a control sample to the drug impurity research and production quality control process of varenicline tartrate, and a guarantee is provided for the genotoxicity research and comprehensive quality control of a varenicline tartrate bulk drug.

The invention relates to a cefpodoxime proxetil impurity, namely cefpodoxime dipivoxil and a preparation method thereof, belonging to the technical field of drug impurity synthesis. The invention aims to provide a novel impurity with high purity and quality. According to the invention, the method comprises the following steps: adding raw materials including cefpodoxime proxetil and 1-iodoethyl isopropyl carbonate into a non-water-soluble benign organic solvent, adding organic alkali to control the pH value of the system to be 8.0-10, carrying out condensation reaction under the condition that a temperature is controlled to be 20-45 DEG C, and obtaining the corresponding product cefpodoxime proxetil impurity, namely cefpodoxime dipivoxil after the reaction is ended. The novel impurity provided by the invention can be used for impurity control of cefpodoxime proxetil synthesis, and has the advantages of high yield and product purity of 93% or more.

The invention belongs to the technical field of chiral drug impurity preparation, and mainly relates to a resolution method of a chiral drug levocetirizine hydrochloride impurity (R)-1-((2-chlorphenyl)-(phenyl)-methyl)-piperazine. The resolution method comprises the steps that racemic 1-((2-chlorphenyl)-(phenyl)-methyl)-piperazine and a resolution agent (S)-(-)-alpha-methylbenzyl isocyanate are dissolved into an organic solvent and react to generate precipitate of (R)-1-((2-chlorphenyl)-(phenyl)-methyl)-piperazine-(S)-(-)-alpha-methylbenzyl isocyanate salt, the precipitate is filtered and washed with acetone to obtain the (R)-1-((2-chlorphenyl)-(phenyl)-methyl)-piperazine-(S)-(-)-alpha-methylbenzyl isocyanate salt, the (R)-1-((2-chlorphenyl)-(phenyl)-methyl)-piperazine-(S)-(-)-alpha-methylbenzyl isocyanate salt is dissolved by adding water, the pH is regulated with a saturated sodium carbonate solution to be 8.0, extraction is conducted by adding ethyl acetate, and drying, filtering and concentrating are conducted to obtain (R)-1-((2-chlorphenyl)-(phenyl)-methyl)-piperazine. The resolution method has the advantages that the product purity is high, the reaction time is short, the reaction temperature is low, and the yield is high; in addition, the solvents are acetone and ethyl acetate and are easy to obtain, free of toxicity, easy to recycle and little in environmental pollution.

The invention relates to a drug impurity detection method based on tenofovir alafenamide fumarate tablets, comprising, step S1, preparing a solution to be tested, the solution to be tested includes a sensitivity solution, a control solution, a system adaptability solution and a sample solution; Step S2, start the detection system to detect the content of each component in the solution to be tested. If the sensitivity of the current detection system does not meet the preset standard, the central control unit will store the last detection result in the information storage module to perform a test on the gradients of each stage set in the detection system. Adjust the phase content and elution time, start the cleaning device installed in the chromatography column, and the central control unit obtains the cleaning frequency to clean the chromatography column according to the last detection result stored in the information storage module; step S3, the central control unit cleans the chromatography column according to the Measure the chromatogram of the solution to obtain the amount of each impurity in tenofovir alafenamide fumarate tablets. Among them, the central control unit compares the amount of each impurity with the preset amount of impurities to determine the quality of the current tenofovir alafenamide fumarate tablet. Make a judgment.

The invention provides an avanafil impurity D as well as a synthesis method and application thereof. According to the novel avanafil impurity and the synthesis method thereof, the structure of the impurity is determined by synthesizing and characterizing the impurity, the drug impurity spectrum of avanafil is perfected, and the obtained product is high in purity and can be used as a reference substance for drug quality control research.

The invention provides an environment-friendly preparation method of an ibuprofen impurity H, and belongs to the technical field of preparation of drug impurity standard substances. The method comprises the following steps: step 1, reacting a compound shown as a formula (I) with a compound shown as a formula (II) under the catalytic action of NaOC2H5 to prepare a compound shown as a formula (III);and step 2, reacting the compound shown in the formula (III) in the presence of CH3MgBr to prepare the ibuprofen impurity H. The method has the advantages of simplicity in operation, short preparation period, few byproducts, easiness in purification, high yield and environmental friendliness; the prepared ibuprofen impurity H is high in purity and free of obvious impurity points and meets the requirements of impurity reference substances and can be used as an ibuprofen impurity H standard substance to be applied to qualitative and quantitative research and detection of the ibuprofen impurityH so as to improve the accuracy of the detection method.

The invention relates to the field of piperaquine phosphate impurity control, and specifically relates to a control method of piperaquine phosphate impurity. The control method of piperaquine phosphate impurity comprises the following steps: 1), adding a non-polar solvent into a piperaquine phosphate crude product, stirring and filtering; 2), adding a polar solvent, conducting reflux, stirring and filtering; 3), adding a water / polar mixed solvent, stirring and dissolving at 90-110 DEG, adding activated carbon for decoloring and filtering to obtain a filtrate, cooling, crystallizing, filtering, washing and drying. The steps 1) 2) and 3) are not in a particular order. The control method of piperaquine phosphate impurity provided by the invention has the advantages of simple process, and extensive equipment and reagent sources, thus indirectly reducing cost for drug impurity removal, and can be widely applied to preparation of piperaquine phosphate.

The invention provides a preparation method of a phenylephrine hydrochloride impurity standard substance, which comprises the following steps: putting an phenylephrine hydrochloride bulk drug under anillumination condition to generate impurities, and obtaining chromatographically pure target impurities by preparative chromatography; in the presence of ketoreductase KRED and reduced coenzyme II NADPH, taking nitromethane and m-hydroxybenzaldehyde as raw materials to react to obtain a concentrate; and finally, recrystallizing the concentrate by using an isopropanol-n-propyl acetate-acetonitrilemixed solution, adding chromatographically pure target impurities neutralized by alkali in the recrystallization process, and salifying to obtain the phenylephrine hydrochloride impurity standard substance (impurity A) which is high in product yield and purity and meets the requirements of drug impurity standard substances.