The Correlation Research On The Pharmacokinetics Of Cefoperazone, Pazufloxacin And Ornidazole Concentration In Saliva, Gingival Crevicular Fluid And Plasma

Orofacial infection is usually mixed infection of aerobic and anaerobic bacteria, the current antibiotics against those pathogenic bacterium include both wide-spectrum antibiotics and those which have strong antibacterial action specific against gram-positive and gram-negative bacillus or coccus. With the growing abuse of antibiotics, the drug adverse reaction and drug resistance are receiving more and more attention. Therapeutic drug monitoring is to messure the drug concentration in blood or other body fluid by morden analytical technology, providing the renferences for doctors to select and adjust drug regim, to prevent and decrease the drug adverse reaction and drug resistance. At present, some research have proved that persistent and predictable correlation exist between the saliva concentration and serum concentration for certain drugs, for these drugs, the saliva can replace serum to monitor the serum concentration, this method is simple, non-invasive, and easy for patient to accept. More and more researches have now focused on this area. Cefoperazone (CPZ), pazufloxacin (PAZ), ornidazole (ONZ) are three new antibiotics used against orofacial infection, their distribution in saliva and gingival crevicular fluid (GCF) remain unclear, furtherly it is still unknown whether saliva can be used to mornitor the drug concentration for these three antibiotics. Besides, the past research about the distribution of these drugs in GCF and drug serum concentration monitoring with GCF are scared, based on those status, this research aimed to investigate the distribution of CPZ, PAZ and ONZ in saliva, GCF and serum to determine the feasibility of monitoring drug serum concentration with saliva and GCF, the whole research have two parts:The construction HPLC method for three antibioticsObjective: To set up high-performance liquid chromatography (HPLC) method for detecting CPZ, PAZ and ONZ in saliva, GCF and serum. Method: Chromatography was carried out on a reversed-phase column (Agilent Zorbax SB-C₁₈ ;5μm, 150mmx4.6mm) for CPZ and ONZ, Agilent Zorbax SB-C₁₈ (5μm, 250mmx4.6mm) for PAZ. The mobile phase for CPZ consisted of acetonitrile and 0.02mol/L KH₂PO₄(1:6); the mobile phase for PAZ was a mixture of acetonitrile and 0.5% phosphoric acid containing 1% triethylamine (155:850); the mobile phase for ONZ was methanol-water (25:75). 20μl of the resulting solution was injected into the HPLC system at a flow rate of 1.0ml/ min, and the wavelength was seted at 254, 245 and 316 nm, respectively. The samples were deproteinised with acetonitrile, then extracted with methylene dichloride for CPZ; for PAZ, methanol was used to precipitate the impurity in the samples; samples were extracted with isopropanol-chloroform (5: 95) for ONZ. Results: The CPZ, PAZ and ORN in saliva and serum were separated on the baseline, the calibration curves showd favorable linear regression (r>0.999). The coefficients of variation for within-day and between-day performance were found to be all less than 5%; the recovery rates were all above 80%. Conclusion: The HPLC methods for messureing the concentration of cefoperazone, pazufloxacin and ornidazole had a high sensitivity, the precision and recovery rates were high and stable. These methods could be applied for the detections of these drugs in saliva, GCF and serum.The distribution of three antibiotics in saliva and GCFObjective: To observe the distribution of three antibiotics in saliva and GCF, and to determine the feasibility of monitoring serum drug concentration with saliva and GCF. Method: Twenty healthy volunteers were divided into three groups: 1) cefoperazone 1.5g; 2) pazufloxacin 0.3g; 3) ornidazole 0.6g, all the subjects were intervenously administrated antibiotics in 30 min. The concentrations of CPZ, PAZ and ONZ in saliva, GCF, and serum were assayed by HPLC, analysis of the correlation of the drug concentration in saliva or gingival crevicular fluid to that in serum was then performed. Results: 1. The concentration of ORN in saliva was strongly associated with plasma concentration (r=0.825～0.969), the ratio of saliva-to-plasma concentration (S/P) of ONZ was 0.99±0.13. The concentration of all the three antibiotics in GCF had no significant association with plasma concentration, both the concentration of CPZ and PAZ in saliva and GCF had no significant association with plasma concentration. 2. The distribution of all the three antibiotics in GCF could not achieve suitable compartment model because of obvious individual differences. 3. The Cmax of CPZ in samples decreased in order of serum (110.40±32.66μg/mL), GCF (38.98±29.23μg/mL), saliva (0.41±0.51μg/mL), for PAZ that is serum (9.46±3.38μg/mL), GCF (1.68±1.03μg/mL), saliva (0.40±0.13μg/mL), the Cmax of CPZ and PAZ in three samples were all significantly different (p<0.05); the highest Cmax of ONZ was in saliva (6.89±1.50μg/mL), next is serum (6.45±1.21μg/mL), the lowest was in GCF (5.61±1.24μg/mL). The distribution of ORN in saliva corresponded to three compartment model. The pharmacokinetic parameters were as follows: Cmax(7.05±1.36)μg/mL, t1/2β(15.13±2.63) h,AUC0-∞(80.58±17.2)μg.h/ml, AUCO-t (68.26±13.79)μg.h/ml; the distribution of PAZ in saliva of partial subjects corresponded to three compartment model, the pharmacokinetic parameters were as follows: Cmax(0.46±0.13μg/mL), t1/2β(1.21±1.03h), AUC0-∞(0.53±0.13μg.h/ml), AUC0-t(0.46±0.17μg.h/ml). For great individual differences of CPZ in saliva and GCF, no favorable compartment model could be achieved. Conclusion: 1. While ORN determined in saliva seems to be suitable for therapeutic drug monitoring, it could not be applied for CPZ and PAZ. 2. All the three antibiotics determined in GCF seems to be unsuitable for therapeutic drug monitoring. 3.ORN could rapidly distribute to saliva, and had highest concentration in saliva and relative longer elimination time, and the concentration of CPZ and PAZ in saliva and GCF were low.