Design of a microporous controlled delivery system for theophylline tablets

Author(s): Lin WJ, Lee HG


The aim of present work was to develop a microporous-controlled delivery system for theophylline via coating a blend of PCL and PEG on the surface of tablets, where PCL was the major component of film coating material and PEG was acted as a leachable pore-forming agent when contacting with an aqueous medium. The influences of the type of solvent, the amount of PEG, and the thickness of films on the mechanical and thermal properties of coating films and drug release performance were investigated. The DSC thermograms and FTIR spectra indicated both PCL and PEG remained independently in the blended films. The mechanical data showed a decrease tendency as increase in the amount of PEG in the blends due to highly crystalline character of PEG. Slower evaporation rate of acetone than dichloromethane enhanced phase separation between PCL and PEG during film formation, and resulted in the pore size in films prepared from acetone larger than from dichloromethane. The release rate of coated tablets were increased by increasing the amount of pore-forming agent, and the corresponding values from tablets coated in dichloromethane were less than in acetone. Much denser structure and smaller pore size of films formed from dichloromethane contributed to this result. The release of drug from tablets coated in acetone showed a profile more close to a zero-order constant release profile. The penetration of water into drug core played an important role in influencing drug release pattern.

Similar Articles

Aqueous polymeric film coating

Author(s): Miller AD, Mcginity JW

Tablet coating in an aqueous system

Author(s): Tondachi M, Hoshi N, Sekigawa F

Pharmaceutical coating technology

Author(s): Cole G, Aulton ME, Hogan J

Tablet coating

Author(s): Hogan JE

Grewia gum as a potential aqueous film coating agent

Author(s): Ogaji IJ, Okafor IS, Hoag SW

Grewia gum as a potential film coating agent

Author(s): Ogaji IJ, Okafor IS, Hoag SW

Silk fibroin as a novel coating material for controlled release of theophylline

Author(s): Bayraktar O, Malay O, Ozgarip Y, Batigün A

The relation of product formulation to absorption of oral theophylline

Author(s): Weinberger M, Hendeles L, Bighley L

Disintegration of tablets

Author(s): Lowenthal W

Evaluation of tablets

Author(s): Banker GS, Anderson NR