Preparation method of hollow polylactic acid microcapsules consisting of poly(L-lactic acid) and poly(D-lactic acid)

Abstract

The invention relates to a preparation method of hollow polylactic acid microcapsules consisting of poly(L-lactic acid) and poly(D-lactic acid). The method comprises steps as follows: adding a poly(L-lactic acid) solution or a poly(D-lactic acid) solution to calcium carbonate particles, and performing oscillation and centrifugal washing to obtain single-layer polylactic acid microspheres; adding the poly(D-lactic acid) solution or the poly(L-lactic acid) solution to the single-layer polylactic acid microspheres, and performing oscillation and centrifugal washing to obtain double-layer polylactic acid microspheres; repeating the steps to obtain multi-layer polylactic acid microspheres; adding an acid solution to the multi-layer polylactic acid microspheres, removing calcium carbonate, and performing centrifugal washing to obtain the hollow polylactic acid microcapsules. The assembly process is simple, the condition is mild, and no special equipment is required; the particle size distribution of the prepared polylactic acid microcapsules is uniform, the particle size and the capsule wall thickness can be controlled accurately, so that controlled release of substances carried in the microcapsules is realized, and the preparation method can be widely applied to fields of drug sustained release, cosmetics and the like.

Description

technical field [0001] The invention belongs to the field of preparation of microcapsules, in particular to a preparation method of polylactic acid hollow microcapsules composed of poly-L-lactic acid and poly-D-lactic acid. Background technique [0002] Microcapsule technology refers to the technology of encapsulating solid or liquid with film-forming materials to form tiny particles. When the microcapsule is formed, the capsule core and the outside world are separated by the capsule wall, and the properties of the capsule core can be completely preserved. Under appropriate conditions, the properties of the capsule wall material change, and the capsule core material can be released, thereby Get the effect of controlled release. Therefore, microcapsule technology has been widely used in various fields such as medicine, cosmetics, food and agricultural production. [0003] According to the properties of microcapsules and the formation mechanism of the capsule wall, the prepa...

AI Technical Summary

Problems solved by technology

[0009] Due to technical limitations, the above-mentioned traditional microcapsule preparation methods have some unavoidable shortcomings: (1) The particle size and wall thickness of the capsules obtained by the traditional microcapsule preparation methods cannot be precisely regulated, resulting in the basic properties of the capsules, such as The dispersion of microcapsule particle size is relatively large, and the sustained release rate cannot be precisely controlled; (2) The phenomenon of microcapsule agglomeration is relatively serious, because the surface free energy of the capsule increases sharply after the particle size of the capsule decreases, resulting in agglomeration; (3 ) In the preparation process of traditional microcapsules, the ability to adjust the microcapsules is limited, and the change of experimental conditions cannot directly change the properties of the capsules, such as particle size, capsule wall thickness, permeability, etc.

Because the molecular chain structure of polylactic acid is simple and uncharged, at present, traditional spray drying, solvent evaporation and other methods are basically used to prepare microcapsules, which cannot realize the regulation of the particle size and wall thickness of the microcapsules, resulting in microcapsules The sustained release rate of the drug coated in medium cannot be precisely regulated