Didanosine extended-release matrix tablets: optimization of formulation variables using statistical experimental design.

Statistical experimental design was applied to evaluate the influence of some process and formulation variables and possible interactions among such variables, on didanosine release from directly-compressed matrix tablets based on blends of two insoluble polymers, Eudragit RS-PM and Ethocel 100, with the final goal of drug release behavior optimization. The considered responses were the percent of drug released at three determined times, the dissolution efficiency at 6 h and the time to dissolve 10% of drug. Four independent variables were considered: tablet compression force, ratio between the polymers and their particle size, and drug content. The preliminary screening step, carried out by means of a 12-run asymmetric screening matrix according to a D-optimal design strategy, allowed evaluation of the effects of different levels of each variable. The drug content and the polymers ratio had the most important effect on drug release, which, moreover, was favored by greater polymers particle size; on the contrary the compression force did not have a significant effect. The Doehlert design was then applied for a response-surface study, in order to study in depth the effects of the most important variables. The desirability function was used to simultaneously optimize the five considered responses, each having a different target. This procedure allowed selection, in the studied experimental domain, of the best formulation conditions to optimize drug release rate. The experimental values obtained from the optimized formulation highly agreed with the predicted values. The results demonstrated the reliability of the model in the preparation of extended-release matrix tablets with predictable drug release profiles.

[1]  Richard Verseput,et al.  Process Optimization Using Design of Experiments , 1997 .

[2]  M. Khan,et al.  Statistical Optimization of Ketoprofen-Eudragit® S100 Coprecipitates to Obtain Controlled-Release Tablets , 1996 .

[3]  Sandra Furlanetto,et al.  Designing experiments to optimise and validate the adsorptive stripping voltammetric determination of nimesulide , 2000 .

[4]  K. A. Khan The concept of dissolution efficiency , 1975, The Journal of pharmacy and pharmacology.

[5]  S. Neau,et al.  Consolidation of ethylcellulose: Effect of particle size, press speed, and lubricants , 1995 .

[6]  J. Fredrickson,et al.  A mixture experiment approach for controlling the dissolution rate of a sustained-release tablet. , 1998, Drug development and industrial pharmacy.

[7]  R. Renoux,et al.  Experimentally Designed Optimization of Direct Compression Tablets , 1996 .

[8]  Kozo Takayama,et al.  Multi-objective simultaneous optimization technique based on an artificial neural network in sustained release formulations , 1997 .

[9]  A. Sakr,et al.  Application of multiple response optimization technique to extended release formulations design. , 2001, Journal of controlled release : official journal of the Controlled Release Society.

[10]  William G. Cochran,et al.  Experimental Designs, 2nd Edition , 1950 .

[11]  S. Leucuţa,et al.  Optimization of propranolol hydrochloride sustained-release pellets using box-behnken design and desirability function. , 1998, Drug development and industrial pharmacy.

[12]  Indra K. Reddy,et al.  Atenolol gastrointestinal therapeutic system: optimization of formulation variables using response surface methodology , 1997 .

[13]  R. Gotti,et al.  Design of experiments for capillary electrophoretic enantioresolution of salbutamol using dermatan sulfate. , 2000, Journal of chromatography. A.

[14]  C. Goodman United States Pharmacopeial Convention , 1988 .