Abstract:

Objective　To determine the dynamic release of tinidazole from the degradable poly-lactic acid (PLLA)-tinidazole blend gel (a periodontal local drug delivery) by high-performance liquid chromatography (HPLC)in vitroand to observe the poly- lactic acid (as a vector of tinidazole) howto affect the release of tinidazole.Methods　HPLC analysiswas conducted. The oper- ating conditions were C18-ODS-A column, water-methanol-acetic acid as mobile phase at a flowrate of 1·5 ml/min and a detection wavelength at 310 nm and a column temperature at 30℃.Results　①The retention time of tinidazole was about 12 min. ②There was good linear relationship between the concentrations of tinidazole in blend gel and their peak areas in the ranges of 5~ 500 mg/L. The regression reactionwasy=0·836+8·452 2×10-5x(r=0·998 6). RSDwas 0·2%.③Polylactic acid had no influence on the determination of tinidazole. The daily average release of tinidazole was 5·60%.The cumulative release of tini- dazole was about 78·40% in 14 days.Conclusion　Thein vitrodrug release analysis is an useful method in evaluating the per- formance of local drug delivery system. HPLC analysis is a simple and accurate method with good reproducibility.

Key words: high-performance liquid chromatography, poly-lactic acid, tinidazole