Preparation of brushite calcium phosphate cement for controlled drug delivery and its property of drug loading

Yang Di-cheng; Zhong Jian; Liu Tao; Yan Ce; He Dan-nong

doi:10.3969/j.issn.2095-4344

Abstract：BACKGROUND:Compared with other calcium phosphate cemenst, brushite calcium phosphate cement has better biodegradabilityin vivo, as it can be quickly absorbed, which also causes a decrease of its mechanical characters. And it also suffers in application from its fast setting reaction and poor injectability. <br> OBJECTIVE:To cooperate β-tricalcium phosphate used as the main part of the solid phase with appropriate liquid phase to prepare a new brushite calcium phosphate cement formulation so as to improve the solidification properties and observe the controled drug-releasing capabilities. <br> METHODS:β-tricalcium phosphate was synthesized by calcining calcium carbonate and calcium hydrogen phosphate. The liquid phase was prepared by mixing citric acid, phosphorylated chitosan, gelation and hydroxypropyl methyl celulose in anaqueous solution. The solid phase which consisted of β-tricalcium phosphate and monocalcium phosphate was mixed with the liquid phase to acquire brushite calcium phosphate cement. Microstructure, composition, particle size and distribution, setting time, compressive strength and drug-releasing capability of the prepared brushite calcium phosphate cement were detected. <br> RESULTS AND CONCLUSION:β-tricalcium phosphate powder was a micro/nano blending system, with diameters of (2.24±0.38) μm in micron particle and (334.95±151.62) nm in nanoscale particle. Brushite belongs to lamelae tightly accumulated. The main component of the calcium phosphate cement powder was brushite, while a part of unreactedβ-tricalcium phosphate also existed. For the brushite calcium phosphate cement, the setting time was (6.20 ±1.30) minutes and the compressive strength was (22.90±3.13) MPa. The drug releasing experiment indicated that the brushite calcium phosphate cement also has certain controled-releasing capability.