Bimodal drug release achieved with multi-layer matrix tablets: transport mechanisms and device design

Junginger, 1993, Oral applications of pulsatile drug delivery, 113 Siepmann, 1999, HPMC-matrices for controlled drug delivery: a new model combining diffusion, swelling and dissolution mechanisms and predicting the release kinetics, Pharm. Res., 16, 1748, 10.1023/A:1018914301328 Siepmann, 1999, A new model describing the swelling and drug release kinetics from hydroxypropyl methylcellulose tablets, J. Pharm. Sci., 88, 65, 10.1021/js9802291 P. Colombo, A. La Manna, U. Conte, System for the controlled-rate release of active substances, U.S. Patent 4,839,177, June 13, 1989. Colombo, 1990, Drug release modulation by physical restrictions of matrix swelling, Int. J. Pharm., 63, 43, 10.1016/0378-5173(90)90099-P Colombo, 1992, Swelling characteristics of hydrophilic matrices for controlled release: new dimensionless number to describe the swelling and release behaviour, Int. J. Pharm., 88, 99, 10.1016/0378-5173(92)90307-N Bettini, 1994, Swelling and drug release in hydrogel matrices: polymer viscosity and matrix porosity effects, Eur. J. Pharm. Sci., 2, 213, 10.1016/0928-0987(94)90025-6 P. Colombo, A.C. Cardona, G. Pifferi, Multilayer matrix systems for the controlled release of active principles, E.P. Patent 0,598,309, May 25, 1994. Qiu, 1998, Design and evaluation of layered diffusional matrices for zero-order sustained release, J. Control. Release, 51, 123, 10.1016/S0168-3659(97)00119-3 Chidambaram, 1998, Formulation and characterization of new layered diffusional matrices for zero-order sustained release, J. Control. Release, 52, 149, 10.1016/S0168-3659(97)00207-1 A.C. Shah, Therapeutic formulations with bimodal release characteristics, W.O. Patent 87/00044, January 15, 1987. Shah, 1989, Gel-matrix systems exhibiting bimodal controlled release for oral drug delivery, J. Control. Release, 9, 169, 10.1016/0168-3659(89)90007-2 Sirkiä, 1994, Development and biopharmaceutical evaluations of a new press-coated prolonged-release salbutamol sulphate tablet in man, Eur. J. Pharm. Sci., 1, 195, 10.1016/0928-0987(94)90004-3 Sirkiä, 1994, Effect of potassium carbonate and viscosity grade of hydroxypropylmethylcellulose on the bioavailability of furosemide from press-coated prolonged-release tablets, S.T.P. Pharma Sciences, 4, 257 Halsas, 1998, Effect of different combinations of hydroxypropylmethyl cellulose on bioavailability of ibuprofen from press-coated time-controlled tablets, S.T.P. Pharma Sciences, 8, 155 Siepmann, 2000, Calculation of the required size and shape of hydroxypropyl methylcellulose matrices to achieve desired drug release profiles, Int. J. Pharm., 201, 151, 10.1016/S0378-5173(00)00390-2 J. Siepmann, N.A. Peppas, Hydrophilic matrices for controlled drug delivery: an improved mathematical model to predict the resulting drug release kinetics (the “sequential layer” model). Pharm. Res., in press. Ju, 1995, Drug release from hydrophilic matrices. 1. New scaling laws for predicting polymer and drug release based on the polymer disentanglement concentration and the diffusion layer, J. Pharm. Sci., 84, 1455, 10.1002/jps.2600841213 Ju, 1995, Drug release from hydrophilic matrices. 2. A mathematical model based on the polymer disentanglement concentration and the diffusion layer, J. Pharm. Sci., 84, 1464, 10.1002/jps.2600841214 Pham, 1994, Probing the mechanisms of drug release from hydroxypropylmethyl cellulose matrices, Pharm. Res., 11, 1379, 10.1023/A:1018975318805 Rajabi-Siahboomi, 1996, Structure and behavior in hydrophilic matrix sustained release dosage forms: 4. Studies of water mobility and diffusion coefficients in the gel layer of HPMC tablets using NMR imaging, Pharm. Res., 13, 376, 10.1023/A:1016084224084 Crank, 1975 Siepmann, 1998, Calculation of the dimensions of drug–polymer devices based on diffusion parameters, J. Pharm. Sci., 87, 827, 10.1021/js980006a Narasimhan, 1996, Disentanglement and reptation during dissolution of rubbery polymers, J. Polym. Sci., Polym. Phys., 34, 947, 10.1002/(SICI)1099-0488(19960415)34:5<947::AID-POLB13>3.0.CO;2-B Narasimhan, 1996, On the importance of chain reptation in models of dissolution of glassy polymers, Macromolecules, 29, 3283, 10.1021/ma951450s Narasimhan, 1997, Molecular analysis of drug delivery systems controlled by dissolution of the polymer carrier, J. Pharm. Sci., 86, 297, 10.1021/js960372z Fujita, 1961, Diffusion in polymer–diluent systems, Fortschr. Hochpolym.-Forsch., 3, 1, 10.1007/BFb0050514 Bodmeier, 1989, Evaluation of biodegradable poly(lactide) pellets prepared by direct compression, J. Pharm. Sci., 78, 819, 10.1002/jps.2600781008 Fan, 1989 Technical information: an improved aqueous coating using Shin-Etsu Aqoat, Shin-Etsu Chemical Co., Tokyo, 1994.