Sustained-releasing praziquantel (SRP) tablet was designed for single dose treatment regimen of clonorchiasis. A previous pre-clinical study confirmed its sustained-releasing characteristics and a better cure rate than conventional praziquantel (PZQ). In this clinical study, the pharmacokinetics of this SRP tablet were investigated in human volunteers (phase 1; 12 volunteers), and its curative efficacy was examined in clonorchiasis patients (phase 2; 20 volunteers). In the phase 1 clinical study, blood concentrations of both tablets showed wide individual variation. The AUC(last) of SRP was 497.9+/-519.0 ng.hr/ml (mean+/-SD) and PZQ of 628.6+/-695.5 ng.hr/ml, and the AUC(inf) of SRP was 776.0+/-538.5 ng.hr/ml and of PZQ 658.6+/-709.9 ng.hr/ml. C(max) values of SRP and PZQ were 90.7+/-82.2 ng/ml and 214.9+/-251.9 ng/ml, and T(max) values were 3.42+/-1.43 hr and 1.96+/-1.23 hr, respectively. SRP tablets showed similar AUC values, but lower C(max) and longer T(max) values than PZQ. In the phase 2 study, SRP at 30 mg/kg (single dose) achieved a 60% cure rate and a 95.5% egg reduction rate. The cure rate of a single dose SRP was unsatisfactory compared with that of the conventional PZQ dose, but much better than that achieved by a single dose PZQ.
*Praziquantel/adverse effects/pharmacokinetics/therapeutic use ; Parasite Egg Count ; Male ; Humans ; *Delayed-Action Preparations/pharmacokinetics/therapeutic use ; Clonorchis sinensis/*drug effects/isolation & purification ; Clonorchiasis/*drug therapy ; Area Under Curve ; *Anthelmintics/adverse effects/pharmacokinetics/therapeutic use ; Animals ; Adult

Adrenergic beta-2 Receptor Agonists ; administration & dosage ; pharmacokinetics ; therapeutic use ; Asthma ; drug therapy ; Bronchitis ; drug therapy ; Bronchodilator Agents ; administration & dosage ; therapeutic use ; Child ; Child, Preschool ; Delayed-Action Preparations ; Drug Synergism ; Drug Therapy, Combination ; Glucocorticoids ; administration & dosage ; therapeutic use ; Humans ; Infant ; Leukotriene Antagonists ; administration & dosage ; therapeutic use ; Respiratory Sounds ; drug effects ; Terbutaline ; administration & dosage ; analogs & derivatives ; pharmacokinetics ; therapeutic use ; Transdermal Patch

OBJECTIVETo develop a colon-specific prodrug of Indomethacin microbially triggered, carry out in vitro/in vivo evaluation of drug release, and appraise its inhibitory effect on liver metastasis from colon cancer.

METHODSIndomethacin prodrugs were synthesized and characterized by FTIR and NMR, and dissolution test simulating gastrointestinal tract was employed to screen the colon-specific prodrug. Then, the pharmacokinetic profile of portal vein and peripheral blood in Sprague-Dawley rats was studied. Lastly, the inhibitory effect on liver metastasis from colon cancer in nude mice was observed.

RESULTSThe chemical structure characterized by FTIR and NMR demonstrated that six kinds of indomethacin-block-amylose with different drug loading (IDM-AM-1-6) were synthesized, among which IDM-AM-3 was degraded 1.3%, 9.3% and 95.3%, respectively, in simulated gastric fluid for 4 h, small intestine for 6 h, and colon for 36 h. The pharmacokinetic test of IDM-AM-3 showed that absorption was delayed significantly (P < 0.01), peak time [(11.35 + or - 2.45) h], elimination half-life [(16.74 + or - 4.04) h] and mean residence time [(22.27 + or - 0.52) h] were significantly prolonged (P < 0.01), as well as peak serum concentrations [(9.69 + or - 2.40) mg/L] and AUC(0-t) [(236.7 + or - 13.1) mg x L(-1) x h] were decreased markedly (P < 0.01) as compared with those of IDM regarding to portal vein. Additionally, its AUC(0-t) in peripheral blood was remarkably lower than that in Portal vein (P < 0.01). The tumor suppression observation showed that it could remarkably reduce the number of liver metastases in contrast to IDM (P < 0.05).

CONCLUSIONColon-specific IDM-AM-3 possesses advantage of sustained release in portal vein providing some experimental basis for colon-specific delivery system applied to sustained release in the portal vein.

Amylose ; administration & dosage ; chemical synthesis ; pharmacokinetics ; therapeutic use ; Animals ; Colon ; metabolism ; Colonic Neoplasms ; pathology ; Delayed-Action Preparations ; Drug Delivery Systems ; HT29 Cells ; Humans ; Indomethacin ; administration & dosage ; chemical synthesis ; pharmacokinetics ; therapeutic use ; Liver Neoplasms ; prevention & control ; secondary ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Prodrugs ; administration & dosage ; chemical synthesis ; pharmacokinetics ; therapeutic use ; Random Allocation ; Rats ; Rats, Sprague-Dawley