Pharmacokinetics Of Active Metabolite Of Prulifloxacin In Healthy Chinese

Prulifloxacin(NM441 or AF3012) was a novel forth generation fluoroquinolone antibacterial developed by Nippon Shinyaku and Meiji Seika(Japan) and not yet launched in China.It is the lipophilic prodrug of NM394,the active metabolite which absciscd 4-[(5-methyl-2-oxo-1,3-dioxol-4-yl)methyl]moiety on C₇ of prulifloxacin by dioxygen enzyme in portal vein and liver after absorbed in the small intestine.Prulifloxacin has a board antibacterial spectrum,including Gram-negative bacteria,Gram-positive bacteria, Anaerobian,Legionella,Chlamydozoan and Mycoplasma.It is generally more active than other fluoroquinolones and antibiotics against Gram-negative bacteria,especially to aeruginosus Bacillus.Studies published abroad showed the drug has little accumulation in vivo after multiple administration.Unlike the other fluoroquinolones with various unexpected toxicity problems(phototoxicity,cardiotoxicity,hepatotoxicity),the rate of adverse effect of it is rare.In order to understand the pharmacokinetics profiles of domestic prulifloxacin tablet developed by Chengdu Kelun Institutes of pharmaceutical research in healthy chinese volunteers,NM394(ulifloxacin)-the active compound was as target in this study.Based on established an RP-HPLC method,the NM394 pharmacokinetics in blood plasma and urine samples were analyzed,so as to get the results for its reasonable clinic use in the future.Methods:1.RP-HPLC method of prulifloxacin assay Investigation of the best conditions of NM394 in plasma and urine samples preparation and chromatography separation.2.Pharmacokinetics of prulifloxacin after single oral administration in healthy volunteers 9 healthy male volunteers were divided into 3 groups according the random chiasm design and orally given 200,300 and 400mg(NM394 content) prulifloxacin tablets for single dose.The plasma and urine samples were collected according to programmed schedul and assayed by RP-HPLC.The pharmacokinetic parameters and the dependability of deference dose were calculated by DAS2.0 software.At the same time the adverse reactions were recorded.3.Pharmacokinetics of prulifloxacin after multiple oral administration in healthy volunteers Other 9 healthy volunteers were enrolled with multiple oral administration of prulifloxacin tablets 300mg(NM394 content) twice daily for 13 times.The plasma and urine samples were collected according to programmed schedule.The pharmacokinetic parameters assay and safety observation were the same as described above.Results:1.A sensitive and selective high performance reversed phase liquid chromatographic method was developed for determination of NM394 in human plasma and urine samples.NM394 was well seperated and there was no significant interferential peak.In plasma samples,the method exhibited a good linearity in 5～5 000ng/mL of NM394 with the lowest detection limit of 2ng/mL.The deviation of recovery ratio was found in the range of 100.64%～101.00%and the standard curve was A= 1.92×10³C+8.97×10²(r=0.9999).Both RSD between days and within day were all lower than 5%.Meanwhile in urine samples,a good linearity in the range of 50～5 000ng/mL and the lowest detection limit of 10ng/mL were obsrerved.The standard curve was calculated to be A=1.11×10³C+3.67×10³(r=0.9999) and the deviation of recovery ratio to be 97.20%～100.20%.And RSD between days or within day were similar to that in plasma samples. These results showed the method established in the study is specific for determination of NM394 and could be used in researching drug pharmacokinetics.2.Pharmacokinetics of prulifloxacin after single oral administration Prulifloxacin is rapidly metabolized into ulifloxacin(NM394) after absorption.The pharmacokinetics of NM394 were fitted in a two-compartment open model following oral administration of single dose of 200,300 and 400mg.The mean peak concentrations(detecting figure)in plasma were 1.488,2.077 and 2.399 mg/L with the mean t_max of 1.167,1.5 and 1.444 h, respectively.Being 9.786,12.903 and 15.22 h·mg/L of the mean area under the concentration-time curve(AUC_0-∞),t_1/2β was found to be 9.00～10.00h.There was a significant correlation was observed between the mean peak concentrations and AUC_0-t. Within 48 h after an oral dose of 200,300 and 400 mg,there 56.9%,54.16%and 44.88%of the doses were excreted in urine,respectively.3.Pharmacokinetics of prulifloxacin after multiple oral administration The pharmacokinetic parameters after the last dose were almost the same as in the single dose. The peak concentration of 2.595 mg/L reached at 1.111h after dosing and t_1/2β was 10.63h. The mean peak concentrations and AUC_0-∞ were higher than that in single dose group.By the matched t-test between the multiple and single dose group,there was a significant difference(P＜0.05) was found in AUC_0-∞,but not in the mean accumulate discharge rate(48h) in urine(P=0.572).Furthermore,C_av,DF and R were 1.089mg/L,1.936 and 1.275. respectively.4.Records of adverse reactions In generally,no serious adverse reactions and significant clinical changes were observed in the period of study.Records of adverse reactions as follows:One volunteer after single oral administration of 400mg showed a slight cardiopalmus and with a feeling of sore waist.And there were cardiopalmus,xerosis cutis,itch,salivary secretion be increased,muscles of lower limb soreness and dry stool found on some volunteer after multiple oral administration.Among them,one volunteer had a transient anosmia lasting 1h at morning and night during 4th～6th day after the drug administration,this symptom recovered completely after test without any medication.And in the laboratory tests a slight rise of AST or ALT with no clinic significance were found and recovered to normal by themselves.Conclusions:1.The established method of RP-HPLC is shown to be simple,rapid,accurate, repetitive and suitable for the clinical pharmacokinetic studies of NM394.2.At the single oral dose of 200,300 and 400mg(NM394 content) prulifloxacin,there was a excellent linear correlation between C_max,AUC and dose.That over 40%of NM394 be excreted in urine within 48h showed it was the main discharge route. 3.No accumulation was found after multiple oral dose of 300mg prulifloxacin.4.The trial was in success and all volunteers were in good compliance.Prulifloxacin administrated orally with single and multiple doses in the study could be tolerable in all volunteers.There were no serious adverse reactions were found and no volunteer dropped out for any reasons during the whole trial.