The Drug Release Investigation Of Calcium Sulfate Combined With MTX In Vitro

Objective: To investigation the character of drug release of calcium sulfate combined with MTX in the circumstance of Tris-buffered natural saline. Methods: The drug particles combined with 20 mg MTX, 4% in weight percentage, were made manually, as the calcium sulfate (OSTEOSET?) for the carrier. The experiment was carried under the condition of 37℃in temperature, rotation rate 50rpn. The mimesis of body fluid was Tris-buffered natural saline. The extraction method was adopted. Samples were collected every 2 hours in the first 24hours and everyday in the next 20 days. The drug concentration of each sample was analyzed through high performance liquid chromatogram. Results: Twenty-five particles were put into the experiment, and twenty were observed throughout the experiment. The average drug concentration of the first two hours was 10.535mg/L, the highest of the first twenty-four hours, and maintains between 4 mg/L and 6mg/L latterly. There was an exponential relation between the accumulative drug concentration and the square root of time. The drug release maintains stably for 18 days, under the rate of 4～6﹪. In the early period, the drug release rate was the highest, from 10 to 11 percent.Conclusion: The drug particles of calcium sulfate (OSTEOSET?) combined with MTX release stably, and the calcium sulfate (OSTEOSET?) was a better carrier of drug implants.