SUSTAINED RELEASE EVALUATION INDEXES(SREI)-A NOVEL METHOD TO EVALUATE SUSTAINED RELEASE PREPARATIONS
Cao De · Chinese Journal of Pharmaceuticals · 1991
The SREI are composed of 4 parameters:(1)The sustained re-lease time index(SRTI)is the ratio of the time when the drug concentration inblood is higher then MEC(minimal effective concentration)to the administra-tion interval.(2)The effective duration(ED)is t_1～t_2,where t_1 is the timewhen the drug concentration in blood reaches MEC after administration,t_2 is the time when the concentration drops to MEC and t_2-t_1 is the time period whenthe concentration is maintained above MEC.(3)The optimum effective concentra-tion index(OECI)is the ratio of the C_(max) to the Mean value of MEC and MTC(minimal toxic concentration).(4)The correct effective therapeutic area(CETA)is the area under blood drug concentration-time curve above MEC,correctedwith SRTI.It is suggested that the SREI be used to evaluate the sustainedrelease preparations more rationally than the traditional parameters(AUC,C_(max)and T_(max)).