Preparation of Phenytoin Sodium Carboxymethyl Chitosan Microsphere and Its Bacteriostasis Experiment Research on Periodontal Common Pathogenic Bacteria

OBJECTIVE To optimize the preparation of phenytoin sodium carboxymethyl chitosan microspheres (PHT-CMCS-MS) using orthogonal test method, and to analyze the components' bacteriostatic effects of two common pathogenic bacteria of periodontal. METHODS The preparation of PHT-CMCS-MS used emulsion chemical cross-linking method and orthogonal test method, with drug loading and entrapment efficiency as index, preparation technology was optimized. Then surfaces of the microspheres were observed, release property and preliminary stability of the microspheres was determined. The bacteriostatic test with common periodontal pathogens (Pg and Aa) was carried out by hole-plate method. The effect of drug was analyzed by comparing the diameter of antibacterial circle. RESULTS The morphologic results showed that the PHT-CMCS-MS appearance in round shape and the particle size distribution range was 0.8-12 µm. The drug-loading rate was 8.2% and entrapment efficiency was 48.9%. The PHT-CMCS-MS in PBS (pH=7.3) had obvious sustained-release effect in solution. The results of in vitro antibacterial test showed that higher concentration of carboxymethyl chitosan, phenytoin and its sustained release microspheres had different bacteriostatic effects on the growth of Pg and Aa. CONCLUSION Combined with biological activity and antimicrobial effect of phenytoin sodium and carboxymethyl chitosan, PHT-CMCS-MS showes a good sustained release effect. It can be combined with surgery or local injections of auxiliary used in periodontal treatment, achieve the goal of periodontal tissue regeneration.