The Higuchi square root equation describes the matris from systems where the solid drug is dispersed in an insoluble matrix, and the rate of drug release is related to the rate of drug diffusion. The composition of various formulations of the tablets with their codes is listed in Table 1. This finding can be attributed to the hydrophobic nature of GC and GD, which retarded drug release from the matrix.

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Absorbance of these solutions was measured at nm using a UV Spectrophoto-meter. Support Center Support Center. The matrix tablets of Verapamil hydrochloride were prepared by wet granulation method using polymers as described in Table 1. Metformin hydrochloride has relatively short plasma half-life, low absolute bioavailability. In pharmaceutical CRDDS, matrix based systems are the most commonly used type of release controlling methodology owing to their simple formulahion be erlease to make the mix suitable for the preparation of tablets by wet granulation or beads 3.

Design of pH-independent controlled release matrix tablets for acidic drugs. Combining Eudragit with gum Copal and gum Damar sustained the drug release for more than 12 h.

How to cite this article: This relation can be used to describe the drug dissolution of several types of modified release pharmaceutical dosage forms, as in case of some transdermal systems etc.

The wide applications of GC and GD formulation and evaluation of sustained release matrix tablets thesis their strong hydrophobic nature, substantial binding property, compatibility with the physiologic environment[ 17 ] and their sustaining property[ 18 ].


Many researchers investigated various natural, semi-synthetic and synthetic polymeric materials. Gel layer thickness, which determines the diffusion path length of the drug, corresponds to the distance between the diffusion and erosion fronts.

Gum copal GC and gum damar GD are natural resinous materials of plant Bursera bipinnata family Burseraceae and Shorea wiesneri family Dipterocarpaceae, respectively. Once daily sustained release matrix tablets of nicorandil-formulation and in vitro evaluation.

Studies in preparation and evaluation of pH independent sustained-release matrix tablets of verapamil HCl using directly compressible Eudragits. All other ingredients used throughout the study were of eevaluation grade and were used as received.

Unlike other antidiabetic drugs metformin HCl does not induce hypoglycemia at any reasonable dose, and hence it is called as an antihyperglycaemic rather than a hypoglycemic drug[ 2 ].

In vitro cumulative release of metformin. The dilutions samples were measured for the absorbance at nm against blank 6.

This was further supported by the lower compressibility index. The prepared matrix tablets were evaluated for hardness, formulation and evaluation of sustained release matrix tablets thesis variation, thickness, friability and reoease content[ 19 ].

Encyclopedia of Pharmaceutical Technology. Release performance of a poorly soluble drug from a novel Eudragit-based multiunite erosion matrix. Kinetic Analysis of release data: The release rate of Verapamil hydrochloride tablets was determined using Dissolution Testing Apparatus 2 paddle method. We are deeply thankful to the Management of C.


The results explain that the dissolution profile of the Verapamil hydrochloride will follow zero order and obeys Higuchi and Korsmeyer- Peppas model. The Sustain release matrix tablet form of Verapamil hydrochloride was prepared by Wet Granulation technique to compare and evaluate the in vitro drug release profile of the formulation.

Assay of Verapamil hydrochloride tablets: The Sciences, ; 1 5: Twenty tablets were selected randomly from each evalustion and powdered in a mortar and accurately weighed tablet powder was placed in 50 ml volumetric flask. Where R and UR are the released and unreleased percentages, respectively, at time t formulation and evaluation of sustained release matrix tablets thesis k 1, k 2k 3k 4and k 5 are the rate constants of zero-order, first-order, Higuchi matrix, Peppas-Korsmeyer, and Hixon-Crowell model, respectively.

A zero-order release would be predicted by the following equation. Compression was carried out using 14 mm flat faced circular punches into tablets on an eight station rotary press tablet compression machine Rimek Minipress I Ahmadabad, India at a constant compression force.