Medium molecular weight hydroxyethyl starch and its purifying method

Abstract

The invention provides a purifying method of medium molecular weight hydroxyethyl starch. The method comprises the following steps: 1, mixing an aqueous solution of medium molecular weight hydroxyethyl starch obtained in an ultrafiltration step of a medium molecular weight hydroxyethyl starch preparation technology with C1-C3 monohydric alcohol to precipitate the medium molecular weight hydroxyethyl starch from the aqueous solution; and 2, separating the medium molecular weight hydroxyethyl starch precipitated in step 1 to obtain purified medium molecular weight hydroxyethyl starch. The invention also provides the medium molecular weight hydroxyethyl starch obtained through the method. The method has industrialized values and can improve the internal quality of a product. The method has the advantages of reduction of the bacterial endotoxin and glycol level of the finished product, economy, energy saving, environmental protection and energy consumption reduction, and is suitable for real needs of the industrialized mass production.

Description

technical field [0001] The invention belongs to the field of pharmacy, and in particular relates to a method for purifying medium-molecular-weight hydroxyethyl starch and the medium-molecular-weight hydroxyethyl starch obtained by the method. Background technique [0002] Medium molecular weight hydroxyethyl starch is a new blood volume expander, its molecular weight distribution is 15,000-400,000 Daltons, the weight average molecular weight is 110,000-150,000 Daltons, the range of substitution degree is 0.36-0.45, and the substitution mode is 9:1. The optimized combination of the above three makes it compared with 706, gelatin, low-molecular dextran and other older generation products, middle molecular hydroxyethyl starch has been obtained with its stable expansion effect, lower side effects and better clinical safety. It is favored by the majority of clinical anesthesia, surgery and ICU doctors, showing a good application prospect. [0003] For example, a conventional med...

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Problems solved by technology

[0007] However, the above-mentioned production process has the following major defects: First, the feed liquid after ultrafiltration is directly spray-dried (spray drying). Toxins and ethylene glycol are two indicators that have a greater impact on patients; secondly, and more importantly, the equipment and facilities required by the direct spray drying method and the cost of operation, maintenance, and use are relatively high. For small and medium-sized enterprises , this approach will lead to consequences that outweigh the gains

Among them, although activated carbon adsorption has a good effect on adsorbing bacterial endotoxin and reducing the content of bacterial endotoxin in the liquid medicine, the adsorption will eventually reach a certain saturated adsorption capacity (≤75%), and if it is necessary to absorb more bacterial endotoxin The method of adding more activated carbon for the purpose of removing toxins will also cause the loss of the main drug components and affect the yield. Therefore, to reduce the bacterial endotoxins in the drug solution to a lower level, this method has its limitations.

Although ultrafiltration can remove a large amount of bacterial endotoxin, for medium molecular weight hydroxyethyl starch, due to the molecular weight distribution of the product (15000-400000) and the molecular weight distribution of bacterial endotoxin (thousands to hundreds of thousands) Larger parts overlap, so this method is also extremely inappropriate for removing bacterial endotoxins in liquid medicine

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