The Study Of Quality Consistency Evaluation Of Generic Drug Nifedipine Sustained Release Tablets ?

Generic drugs are non-original drugs,which completely imitate the main ingredients of the original drug.The active ingredients,dosage forms and routes of administration of Generic drugs must be consistent with the original drug.And the bioequivalent between the generic drugs and original drugs is the most critical thing.China is a large country in generic production and use,but most of the generics produced in China are not up to the original drug efficacy.Under this situation,China put forward and began to implement the task of consistency evaluation for generic drugs.The generic drug of this experiment is Nifedipine,which was first developed and listed by Bayer.By now its production of Adalat(nifedipine sustained release tablets)takes the highest market share and is imitated by others mostly.At present there are seven pharmaceutical companies in China imitating the Adalat,some of the production sale well,however the efficacy of these generic drugs are not satisfied.This experiment was taken for the quality consistency evaluation of Chinese generic drug nifedipine sustained release tablets ?.By establishing a complete consistency evaluation method in vitro,including the evaluation of safety,equivalence and quality of the process,the experiment compared the reference formulation with the generic drug to investigate whether the generic nifedipine sustained-release tablets II are consistent with original drug.To evaluate the safety,it tests the relevant substances and impurities of the preparation.High performance liquid chromatography was selected as the method.The method was sensitive and accurate.It was suitable for the determination of related substances in nifedipine sustained release preparation.Test results showed that substances of the reference preparation and domestic generic are within the scope of quality standards,but the total amount of domestic generic drugs was high.In equivalence studies,the determination of in vivo bioequivalence was replaced by in vitro dissolution behavior test.Experiment selected p H1.2,p H4.5,p H6.8 and water as the dissolution medium by referencing Japanese orange book and added 0.3% Tween 80 as surfactant.Dissolved content determination method used high performance liquid chromatography.Sampling time extended to 24 h.Finally we draw four different p H dissolution curves,and compare the similarity between generic drugs and reference preparation.The method was verified,stable and accurate,suitable for the determination of dissolution curves of nifedipine sustained release tablets.The results showed that the dissolution curves of generic drugs A were not similar to the reference preparation.The dissolution curves of generic drugs B were similar to those of the reference preparation,but the similarity was not high.To evaluate the quality of the process,the experiment took the crystal form of the raw material and the content of the preparation as the evaluation method.X-ray powder diffraction was used as the detection method for crystal form determination and the APIs of reference preparations and domestic generic preparations were determined by high performance liquid chromatography.The results showed that the crystal form of the reference preparation raw materials may be different from the generic drugs.And results showed that the content of domestic generic drugs similar to the reference preparation.Through the evaluation,the conclusion is that though the content and the relevant substances control of domestic generic drugs are similar to the reference preparation,the in vitro equivalence is not meet the requirements.The similarity of the in vitro dissolution behavior was not high.This is the reason why the efficacy of our generic drugs which are totally meet the quality requirements of pharmacopoeia is worse than original drugs.China's generic drugs are just the simple and crude imitation of the original drugs that caused the final poor efficacy and bad equivalent.There are many problems in China's generic drugs.In order to truly improve the quality of generic drugs,we must strictly adhere to the standard of this consistency evaluation,eliminate the low-quality generic drugs,and build some innovative pharmaceutical companies,and enhance the abilities of China's pharmaceutical companies in the international market competitiveness.