Bioequivalence and Bioavailability Forum

Modified Noyes-Whitney equation-
dWt / dt = {D.T.N^1/3.W^2/3.(Xs-Wt)} / V.d.r^2/3
= z.W^2/3.(Cs-C) -------- (1)

where,
Wt = amount dissolved at time t
D = Diffusion co-efficient
T = Shape factor (like in Weibull equation)
N = Number of particles
W = Amount of drug remaining to be dissolved
V = Volume of dissolution
d = Diffusion layer thickness
r = Particle density
Cs = Saturation solubility
Xs = Amount of drug required to saturate dissolution volume

z = Constant equal to following,
z = {D.T.N^1/3} / d.r^2/3
As the values of D, T, d, r, etc are difficult to have for every molecule, z-value can be obtained by fitting the dissolution data to equation (1) or the integrated form of equation (1) (below).

y = (z/V).t ---------(2)
where y is a function of amount brought to dissolution (dose).

I am unable to fit the dissolution data to these equations.
Can anyone please help me with an example.

Thanks in advance,
Sandeep