The Peppas equation can be used to describe the first 60 of

The Peppas equation can be used to describe the first 60% of drug released from a degradable polymer. This equation is sometimes called the power law model and is given by: where M_t is the amount of drug released at a certain time, t, M_infinity is the amount of drug released at infinite time (or after drug release no longer occurs), k is a constant related to the drug diffusivity and the size of the polymer, and n is a diffusional exponent that describes the type of drug release occurring. If a researcher would like to determine n for a given data set. what terms should the researcher graph to obtain a linear plot that would permit n to be identified, and what term in the linear equation would n correspond with?

Solution

LogM_t - LogM = nLogt + Logk,

where Mt is the amount of drug released at time t and M is the amount released at time infinity;

thus, the Mt/M is the fraction of drug released at time t, K is the kinetic constant, and n is the diffusion exponent.

A plot between log of (Mt/M) against log of time will be linear if the release obeys Peppas equation and the slope of this plot represents “n” value.