Back to the Top
Dear all
I am having some problem with the calculation of dissolution study of
a sustained release tablet regarding the release profile of the drug.
Can you please refer me some review articles on higuchi and peppas
korsemayer equation from standard pharmaceutics journals.
Waiting for an early reply.
Thank you.
Back to the Top
The following message was posted to: PharmPK
For the equations, try this article:
http://www.aapspharmscitech.org/articles/pt0704/pt070490/pt070490.pdf
Regards Bert
Back to the Top
Hi Simon,
The following review paper on the dissolution release kinetics may
solve your problem.
Modeling and comparison of dissolution profilesPaulo Costa and Jose
Manuel Sousa Lobo. European Journal of Pharmaceutical SciencesVolume
13, Issue 2, May 2001, Pages 123-133.
Regards,
Rama Rao
Back to the Top
Dear sir
I need step by step nethod to calculate rate constant. Slope.
Intercept and release exponent by using korsemeyer peppas equation
Venkateskumar k
Kmch college of pharmacy
coimbatore
Back to the Top
The following message was posted to: PharmPK
Korsemeyer Peppas equation is applied to non-degradable polymeric
tablets.
The equation is
Q% = b + Kp * t^n
Where Q% is the percent of the drug released at time t, b is the
intercept (it corresponds to the burst), Kp is a constant that depends
on the formulation and n is the release exponent (which indicates the
mechanism of release).
What you need to do is to quantify the drug in a whole tablet, and
then quantify the drug released at several times (you do this in a
dissolution apparatus, where you collect samples at several times).
When you have the percentage released at several times you need to
plot the data. Now you have 2 ways of solving the problem. You could
do an approach, if you consider that your drug doesn't have a burst
effect and you can ignore b,
ln Q% = ln Kp + n * ln t
Which means that if you plot ln Q% vs ln t the slope will be n.
The other way is by non linear regression (e.g. with Solver or I think
WinNonlin can also do this).
The meaning of n, is when it approaches 0.5, the release is driven by
Fick's law, when 0.5 < n < 1.0 non-Fickian release and n near 1 the
release is zero-order (it's constant over time).
Here is the original reference by Peppas
Peppas. Analysis of Fickian and non-Fickian drug release from
polymers. Pharmaceutica acta Helvetiae (1985) vol. 60 (4) pp. 110-1
Andre Mateus
Want to post a follow-up message on this topic?
If this link does not work with your browser send a follow-up message to PharmPK@boomer.org with "Korsemeyer peppas constant" as the subject | Support PharmPK by using the |
Copyright 1995-2011 David W. A. Bourne (david@boomer.org)