Chitosan Loaded Mucoadhesive Microspheres of Gliclazide - Journal

Prakash Rao B et al Formulation and Evaluation of Mucoadhesive Buccal Drug Delivery System of Metoprolol Tartrate by Using Central Composite Design
of optimized formula found to be 0.673 which indicates the
mechanism of release is non Fickian. The factor A with
higher concentration shows the higher effect on value of the
release exponent(n) than the factor B. At high level of factor A
gave high value of n at all level of factor B which indicates that
factor A has significant effect.
Kinetics of Drug Release
The drug release data was fitted into the different model like
Korsmeyer Peppas , first order, zero order and Higuchi
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eqation and shown very close and above 0.9 r values (Table 5).
It suggests that the release of drug from the formulations may
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follow any one of these models.The r values of first order of
all the formulations shows higher which indicate the drug
release is directly proportional to the amount of drug
remaining. But n values range from 0.484 to 0.673 which
indicate non-Fickian diffusion mechanism. According to
Higuchi model, the drug release from matrix is directly
proportional to square root of time and explains the Fickian
diffusion. It may be coincident. However, n values of
Korsmeyer-Peppas strongly indicates that diffusion
mechanism is non-Fickian.
ANOVA, Pure Error, Lack of Fit
The result of ANOVA demonstrate that the model was
singnificant for all dependent variables (Table 6). Regression
analysis was carried out to determine the regression
coefficients. All the independent variables ( Factors) were
found to be significant for all R1, R2, R3 and R4 response
variables. The quadratic model was found to be significant for
R1. The linear model was found to be significant for R3 and
R4. The 2FI model was found to be significant for R2. So,
above result indicate that both the factors play an important
role in the formulation of buccal tablet containing metoprolol
tartrate. The data of pure error and lack of fit are
demonstrated in (Table 6), which can provide a mean
response and an estimate of pure experimental uncertainty.
The residuals are the difference between observed and
predicted value.
Fig 11. DTA thermograms of (A) Metoprolol tartrate
(B) HPC (C) Carbopol (D) Drug + HPC (E) Drug + Carbopol.
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Table 5.Correlation coefficient (R ) of different models, drug release exponents(n), zero order release rate
constants(K 0 ), First order release rate constant(K), Korsmeyer Peppas release constant(K KP)
Kinetic profile of Korsmeyer Peppas Zero order First order Higuchi
formulation n K KP
2
R K 0
2
R K
2
R
2
R
F-1 0.554 2.0792 0.969 0.123 0.989 -0.0021 0.989 0.980
F-2 0.563 1.963 0.985 0.119 0.985 -0.00207 0.998 0.989
F-3 0.488 3.186 0.995 0.112 0.979 -0.00204 0.997 0.996
F-4 0.580 1.760 0.993 0.117 0.981 -0.00201 0.999 0.992
F-5 0.543 2.630 0.964 0.158 0.995 -0.00386 0.923 0.953
F-6 0.485 3.144 0.992 0.110 0.987 -0.00199 0.990 0.990
F-7 0.559 2.0393 0.995 0.118 0.987 -0.00209 0.994 0.991
F-8 0.673 0.888 0.994 0.112 0.996 -0.00176 0.991 0.980
F-9 0.556 1.879 0.9973 0.118 0.984 -0.00203 0.996 0.984
F-10 0.661 1.083 0.998 0.122 0.987 -0.00206 0.996 0.992
F-11 0.506 3.123 0.960 0.150 0.997 -0.00354 0.942 0.959
F-12 0.664 1.038 0.981 0.129 0.994 -0.00221 0.984 0.972
F-13 0.576 1.763 0.973 0.119 0.984 -0.00203 0.996 0.984
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RJPS, Jul - Sep, 2011/ Vol 1/ Issue 2