[Studies on pulsatile release tablets of diltiazem hydrochloride in explosion way].
OBJECTIVE
To investigate the preparation of pulsatile release tablets, the release of the drug in vitro and the pharmacokinetics in vivo.


METHODS
Diltiazem hydrochloride (DIL) was used as model drug. The pulsatile release tablets were prepared by film-coated method using ethylcellulose and Eudragit L. The effect of formulation on pulsatile release of diltiazem hydrochloride was investigated under release rate test. The mechanism of pulsatile release of drug was proved by the test of water-uptake. The pharmacokinetic and bioavailability study in eight human subjects was performed by HPLC method.


RESULTS
The release of diltiazem hydrochloride effected by the formulation of the core tablets and the composition and thickness of the coating film. In vitro, the delayed-release time T10 was 4.4 h, the maximum release time Trm was 8.0 h and the pulsed-release time Trm-10 was 3.6 h. In vivo, the delayed-release time Tlag was 4.9 h, the peak time was 8.0 h and the pulsed-release time was 3.1 h. The relative bioavailability was 105%.


CONCLUSIONS
The release of drug from pulsatile release tablets of diltiazem hydrochloride was shown to be in pulsed way both in vitro and in vivo.
Fan
Tian-yuan
TY
Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing 100083, China. ty-fan@163.net
Wei
Shu-li
SL
Yan
Wen-wei
WW
Ding
Wu-xiao
WX
D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004110:Diltiazem / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D005466:Fluorocarbons / Q000737:chemistry; D006801:Humans; D008297:Male; D011109:Polymethacrylic Acids / Q000737:chemistry
D000959:Antihypertensive Agents; D003692:Delayed-Action Preparations; D005466:Fluorocarbons; D011109:Polymethacrylic Acids; C038300:methylmethacrylate-methacrylic acid copolymer; C012964:ethylcellulose perfluorobutyrate; D004110:Diltiazem