Dynamic Release Of Tinidazole From The Degradable PLLA-tinidazole Blend Gel And The Gel' Zoology Study In Periodontitis' Curative Effect

The degradable poly-lactic acid (PLLA)-tinidazole blend gel is a recent periodontal local drug delivery. For determining the effective durative release time of tinidazole in blend gel in vitro and validating the slow release ability of the degradable poly-lactic acid,we had built high-performance liquid chromatography (HPLC) .And we experimentalized on zoology reseach to compare clinical indices and bacteriological parameters on the blend gel and PERIOCLINE.First part of this study:high-performance liquid chromatography (HPLC) analysis was conducted. The operating conditions were ODS-C18 column (250mm×4.6mm,5μm) , water-methanol-acetic acid (80:20:0.1) as mobile phase at a flow rate of 1.5 ml/min and a detection wavelength at 310 nm and a column temperature at 30℃.The results show that (1) The retention time of tinidazole wasabout 12 min. (2) There was good linear relationship between the concentrations of tinidazole in blend gel and their peak areas in the ranges of 5~ 500 u g/ml. The regression reaction was Y=0.836+8.4522X 10"5x (r=0.9986). RSD=0.2%. (3) Polylactic acid have no influence on the determination of tinidazole. The daily average release of tinidazole was 5.60%.Second part of this study: this was a randomized, single-blinded study.Beagle were selected as subjects in this study , first premolars of maxilla and mandible with probing depths3mm were selected as testing sites,so totally 48 teeth were included .The subjects were randomly divided into experiment groupI,group2 and control group. Local application were performed once a week for 4 weeks.Clinical indices and bacteriological parameters were recorded at the baseline and 1 week,2weeks,3weeks,4weeks respectively.The results show that (l)At the baseline, clinical indices and bacteriological parameters of 3 groups were no significant difference. After treatment compared with baseline, PD,BOP,GI and the amounts of P.gingivalis, P.intermedia, F.nucleatum of 3 groups all markedly reduced. (2)BOP and GI of 3 groups were no significant difference .PD between the blend gel 1 (containing 5% tinidazole) and PERIOCLINE was no significant difference, while a significant difference was observed between the blend gel 2(containing 2.5% tinidazole) and other 2 groups(/><0.05). 4 weeks later, GI of 3 groups had no significant difference was observed in 3 groups. (3)4 weeks later, the amounts of P.gingivalis and F.nucleatum of 3 groups were no significantdifference ,whil the amounts of P. intermedia between the blend gel 1 ,2 and PERIOCLINE was a significant difference(P<0.05).Results from this study indicated that (1) the in vitro drug release analysis is an useful method in evaluating the performance of local drug delivery system . (2) The degradable poly-lactic acid -tinidazole blend gels resembled PERIOCLINE in clinical indices and bacteriological parameters.In the 2 blend gels, the blend gel 1 (containing 5% tinidazole) was better than the blend gel 2(containing 2.5% tinidazole). It indicates local application with the degradable poly-lactic acid -tinidazole blend gel (containing 5% tinidazole) treatment as an adjunct to conventional therapy may lead to a more advantageous outcome for periodontitis.