Sustained-release metformin hydrochloride pellets and preparation method thereof

The invention belongs to the field of medicinal preparations and discloses sustained-release metformin hydrochloride pellets and a preparation method thereof. The sustained-release metformin hydrochloride pellet comprises a drug-containing pellet core and a sustained-release coating coated on the drug-containing pellet core. The drug-containing pellet core comprises 75 to 100 parts by weight of metformin hydrochloride and 0 to 25 parts by weight of one or more excipients, wherein the sum of the part numbers of metformin hydrochloride and the one or more excipients is 100 or the part numbers are increased or decreased based on a certain ratio, and also comprises one or more surfactants and one or more wetting agents, wherein the weight of the one or more surfactants is 0.1 to 8% of the total weight of metformin hydrochloride and the one or more excipients; and the weight of the one or more wetting agents is 0.1 to 30% of the total weight of metformin hydrochloride and the one or more excipients. Through the preparation method, the sustained-release metformin hydrochloride pellets having low friability, a high yield, small particle sizes and smooth surfaces are obtained and are convenient for further processing. In the invention, the drug-containing pellet cores are coated with the sustained-release coatings to form the sustained-release metformin hydrochloride pellets; and a bioavailability experiment is carried out and proves that the sustained-release metformin hydrochloride pellets has the characteristics of controllable quality and good stability in vitro, and has the characteristic of sustained release in vivo.