The Improvement Of Analgin Preparation

Analgin is a kind of anti-inflammatory drugs, which was developed at the beginning of 20th century, and it has been produced for 60 years in China. It is an important export product in pharmaceutical industry. The manufacturing process is relatively developed, but the manufacturing route is long, there are many separation and post-treatment process, which take up a lot of equipments, facilities and human resources.This dissertation is a study of the feasibility for analgin production process improvement. The proposed method is not only simple and suitable for industrial scale production, but also it can improve the quality of analgin, reduce manufacturing costs, and improve the market competitiveness of analgin.This dissertation discusses the improvement for the manufacturing process of analgin. Firstly, the impurities of intermediates formed in the first three steps were determined through using high performance liquid chromatography. Second, on the basis of a large number of experimental results obtained and the different physicochemical properties between 4-aminoantipyrine sulfate and its impurities, 4-aminoantipyrine sulfate was purified effectively through using extraction method after the hydrolysis of this step. The improved process can effectively eliminated the impurities of 4-aminoantipyrine. Therefore, the post-treatment process of 4-formamidoantipyrine mother liquor is simplified, the crystallization yeilds of 4-formamidoantipyrine and analginum were obviously increased, analgin liquor of the original process and was reduced greatly. Consequently, the whole manufacturing process is more simple and reasonable, resulting in reducing the operation personnel, equipment investment, materials and power costs, as well as further decreasing the waste emissions. This has important environmental significance, and playes a great role in promoting dipyrone products in a clean and sustainable way. With this manufacturing process, the quality of analgin intermediate:4-aminoantipyrine, 4-formamidoantipyrine,4-methylaminoantipyrine and the recovery of crude antipyrine has been strikingly upgraded. The qualification rate of antipyrine products for export has been increased from 60% to 100%, and five million yuan of raw material and energy cost for the company have been saved.