摘要
Verapamil is a calcium channel blocker drug which reduces heart rhythm and blood pressure in high blood pressure patient.The steady state of this drug has to be continually controlled to obtain optimal efficacy.In addition,patient compliance needs to be considered.Therefore,controlled release tablet of verapamil hydrochloride was essentially developed using hydrophilic matrix polymer,namely hydroxypropylmethyl cellulose(HPMC)and sodium alginate,and compared to marketed product[1].HPMC,a pH-independent polymer,hydrates to form a gel layer at the surface of the tablet to sustain the drug release.Sodium alginate,a pH-dependent gelling polymer,converts to insoluble alginic acid after exposure to acidic condition in stomach.
