A colon-targeted pH-sensitive hydrogel and its preparation method and application

Abstract

The invention discloses a colon targeting pH sensitive hydrogel, a preparation method and applications thereof. The hydrogel is prepared by the following steps: mixing konjac glucomannan and xanthan gum, then coating a layer of glycerin on the surface of the mixture, the covering the whole system with a certain amount of sodium alginate, and finally drying so as to obtain the hydrogel. By taking the in vitro drug release behavior as a reference, the affects of hydrogel preparation temperature, drug adding sequence, material ratio, glycerin amount, and drug dosage on the release behaviors of drugs which have been respectively put into an artificial gastric fluid for two hours, an artificial intestinal fluid for two hours, and an artificial colon fluid for four hours are studied, optimum hydrogel for in vitro drug release behavior is selected, and the optimum hydrogel provides the closest in-vivo pH change situation. The colon targeting pH sensitive hydrogel solves the problem that in the prior art natural polysaccharide is taken as the drug carrier, the drug is released in advance and cannot reach the colon, so the drug effect is affected in a certain degree; furthermore the operation is simple, the materials are available, the credibility of the selected screening index is high, and the amount of drugs which can reach the colon accounts for about 80%.

Description

technical field [0001] The invention belongs to the technical field of pharmaceutical preparations, and relates to a preparation method and application of a colon-targeted pH-sensitive hydrogel Background technique [0002] Oral colon-specific drug delivery system (OCDDS) uses a drug delivery system to prevent the drug from being released in the upper gastrointestinal tract after oral administration, and then disintegrate or erode and release the drug after it is delivered to the ileocecal region of the human body. , and play a local or systemic therapeutic effect in the large intestine; as a new drug delivery system, colon-targeted drug delivery has become a research hotspot in recent years. A variety of targeting materials have been gradually developed and utilized. [0003] According to the drug release mechanism of different drug delivery systems, OCDDS can be divided into five categories. [0004] (1) pH-dependent OCDDS, pH-dependent OCDDS is based on the physiologica...

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