Biomedical subjects

M K Panchal

Publications and source records attributed to M K Panchal.

4 recordsLinked to original sources

PubMed2002

Novel use of similarity factors f2 and Sd for the development of diltiazem HCl modified-release tablets using a 3(2) factorial design.

The objective of this study was to develop modified-release tablets of diltiazem HCl using a direct compression technique. A 3(2) factorial design was employed using the amount of alkali-treated guar gum and cetyl alcohol as independent variables. This article proposes the use of a novel approach-f2 and Sd values as dependent variables-to evaluate the effect of selected independent variables along with other dependent variables (i.e., percentage drug released in x min, Yx; time required for z% drug release, tz; and mean dissolution time (MDT)). It is concluded that when a decision is to be made for the selection of a best batch, it is perhaps more realistic to use the f2 or Sd value which takes into account the dissolution profile as a whole, as opposed to Yx and tz values which use just one point from the dissolution plot. The batch showing the f2 value nearest to 100 or the Sd value nearest to zero is ranked as the best batch (diltiazem HCl 90 mg, alkali-treated guar gum 80 mg and cetyl alcohol 15 mg). The gel strength and matrix erosion of the formulated tablets were dependent on the type and amount of the adjuvants. The drug release rate is well correlated with matrix erosion. The kinetics of drug release fitted best to the Korsmeyer and Peppas model. It is concluded that by using a proper combination of the hydrophilic polymer and cetyl alcohol one can achieve a desirable drug release pattern.

Delayed-Action Preparations↗

PubMed2000

Novel mathematical method for quantitative expression of deviation from the higuchi model.

A simple mathematical method to express the deviation in release profile of a test product following Higuchi's kinetics from an ideal Higuchi release profile was developed. The method is based on calculation of area under the curve (AUC) by using the trapezoidal rule. The precision of prediction depends on the number of data points. The method is exemplified for 2 dosage forms (tablets of diltiazem HCl and microspheres of diclofenac sodium) that are designed to release the drug over a 12-hour period. The method can be adopted for the formulations where drug release is incomplete (<100%) or complete (100%) at last sampling time. To describe the kinetics of drug release from the test formulation, zero-order, first-order, Higuchi's, Hixson-Crowell's, and Weibull's models were used. The criterion for selecting the most appropriate model was based on the goodness-of-fit test. The release kinetics of the tablets and microspheres were explained by the Higuchi model. The release profiles of the test batches were slightly below the ideal Higuchi release profile. For the test products, observed percentage deviation from an ideal Higuchi profile is less than 16% for tablets and less than 11% for microspheres. The proposed method can be extended to the modified release formulations that are designed to release a drug over 6, 18, or 24 hours. If the data points are not evenly separated, the ideal drug release profile and AUC are calculated according to the specific sampling time. The proposed method may be used for comparing formulated products during the research and development stage, for quality control of the products, or for promoting products by comparing performance of the test product with that of the innovator's product.

Chemistry, Pharmaceutical↗

PubMed2000

Modulation of drug release rate of diltiazem-HCl from hydrogel matrices of succinic acid-treated ispaghula husk.

The feasibility of using succinic acid-treated ispaghula husk in matrix-based tablets of diltiazem-HCl was investigated. The sample prepared using 4:1 weight ratio of ispaghula husk to succinic acid showed improved swelling and gelling. A 3(2) factorial design was employed to investigate the effect of amount of succinic acid-treated ispaghula husk and dicalcium phosphate (DCP) on the percentage of the drug dissolved in 60, 300, and 480 min from the compressed tablets. The results of multiple linear regression analysis revealed that the significance of the amount of succinic acid-treated ispaghula husk was greater in magnitude than that of the amount of DCP in controlling the drug release. Acceptable batches were identified from a contour plot with constraints on the percentage drug released at the three sampling times. A mathematical model was also evolved to describe the entire dissolution profile. The results of F-test revealed that the Higuchi model fits well to the in vitro dissolution data. The tablets showed considerable radial and axial swelling in distilled water. Succinic acid-treated ispaghula husk can be used as an economical hydrophilic matrixing agent.

Calcium Channel Blockers↗

PubMedDate not supplied

Studies in release behavior of diltiazem HCl from matrix tablets containing (hydroxypropyl)methyl cellulose and xanthan gum.

(Hydroxypropyl)methyl cellulose and xanthan gum were used as hydrophilic matrixing agents for preparing modified release tablets of diltiazem HCl. The amount of (Hydroxypropyl)methyl cellulose and xanthan gum exhibited significant effect on drug release from the tablets prepared by direct compression technique. Xanthan gum showed a higher ability to retard the drug release than (Hydroxypropyl)methyl cellulose. A 2(2) + 1 factorial design was adopted to study the effect of amount of (Hydroxypropyl)methyl cellulose and xanthan gum on percent drug released in first hour (Y60) and the time required for 90% drug dissolution (t90). A response surface plot is generated for investigating the effect of the independent variables on t90. The tablets containing 90 mg diltiazem HCl, 45 mg (Hydroxypropyl)methyl cellulose and 45 mg xanthan gum showed drug release upto 12 h. The value of similarity factor, f2, for the selected batch was found to be 85.1 when the dissolution study was carried out in water or simulated gastric fluid, indicating pH independent drug dissolution. The selected batch also showed a comparable release profile with a market product (f2 = 60.2). Linear relationship was observed between percent drug released and degree of swelling. The kinetics of the drug release fitted well to the Hixson-Crowell equation. It can be concluded that by using a suitable blend of (Hydroxypropyl)methyl cellulose and xanthan gum desired modified drug release can be achieved.

Antihypertensive Agents↗