PRACTICAL 18
Aim: To plot Heckel plot, Higuchi and peppas plot and determine similarity factors.
Reference:
Requirement: Beaker, Glass rod, Mortar and pestle, Sieve.
Theory: The Higuchi, Peppas, and Heckel plots are used to determine similarity factors and
predict drug release profiles. The plots are used to optimize the performance of controlled
drug delivery systems.
Here are some details about the Higuchi, Peppas, and Heckel plots:
Heckel plot: The Heckel plot is used to determine similarity factors.
Higuchi model: The Higuchi model is used to describe drug dissolution from
𝑓𝑡=𝑄=𝐴√𝐷(2𝐶с𝐶𝑠)𝐶𝑠𝑡.
modified release pharmaceutical dosage forms. The model's equation is
The data is plotted as cumulative percentage drug release versus square root of time.
o Peppas plot: The Peppas plot is used to analyze drug release from
pharmaceutical formulations. The equation for Korsmeyer-Peppas analysis is
log.
Heckle plot: A Heckel plot is a graph that shows the relationship between the applied compression
pressure and the negative natural logarithm of ε. It's used to study the compaction and compression
behavior of a sample, and to identify the main type of deformation in it.
It is derived by: Ln [1/1-D] = K P+ A
The Heckle equation is one of the most useful equations for describing the compaction properties of
pharmaceutical powders.
PROCEDURE:
1. Calculate the relative density (D) of the powder at each applied pressure.
2. Calculate the porosity (ε) as ε=1−Dε = 1 - Dε=1−D.
3. Calculate the natural log of reciprocal porosity, ln(1/(1−D))\ln(1 / (1 - D))ln(1/(1−D)), at each
pressure.
4. Plot ln(1/(1−D))\ln(1 / (1 - D))ln(1/(1−D)) (y-axis) against the applied pressure (P) (x-axis).
5. The slope of the Heckel plot is associated with the plastic deformation of the powder under
pressure.
Peppas Plot: The Power law or Korsmeyer-Peppas model is used to describe and analyze the release
of a drug from a polymeric nanoparticle’s dosage form such as a hydrogel, or when the release
follows several kinetics mechanisms.
Mt/M∞=Kkptn Log (Mt/M∞) =log Kkp + nlog t
PROCEDURE:
Steps for Korsmeyer-Peppas Plot
1. Construct the table for the release data (Time and Cumulative % drug release).
2. Convert time values and cumulative % drug release values to its log.
3. Use MS Excel to plot graph of log time verses log cumulative % drug release (Scatter with smooth
lines and markers).
4. Add trend line and show equation on the Excel graph.
5. Equation for Korsmeyer-Peppas analysis is as follows:
log (% CDR) = log (a) + n log (t)
6. Calculate slope (n) of graph and R 2 .
Higuchi plot: A Higuchi plot is a graph that shows the cumulative percentage of drug release versus
the square root of time. It's used to study the drug release mechanism from a homogeneous planar
matrix that doesn't dissolve.
Higuchi release model is represented as: The model's equation is
(Q=A\sqrt{D(2C-Cs) Cst} \)
PROCEDURE:
A. Steps for Higuchi Plot
1. Construct the table for the release data (Time and Cumulative % drug release).
2. Convert time values to its square root.
3. Use MS Excel to plot graph of square root of time verses cumulative % drug release (Scatter with
smooth lines and markers).
4. Add trend line and show equation on the Excel graph.
5. Calculate slope (K H ) of graph. 7. Calculate R 2 .
Calculation:
Release Data Heckel Korsmeyer-Peppas Higuchi
Time % CDR Py Porosity(ε) log time log % CDR SQRT % CDR
time
Graphs:
1.Heckel Plot
2.Peppas Plot
3.Higuchi plot
Result:
Heckle plot Peppas plot Higuchi plot
k k
n n
r r
R2
