Osmotic pumps nifedipine

Neural networks have also been used in Slovenia, to model the release characteristics of diclofenac [52] in China, to study release of nifedipine and nomodipine [53] and in Yugoslavia to model the release of aspirin [54], More recently, work in this area has been extended to model osmotic pumps in China [55] and enteric coated tablets in Ireland [56],... 

Rgure 8.38 Cross-section of the push-pull osmotic pump for nifedipine. 

Pfizer s Procardia XL is a once daily calcium channel blocker (CCB) for hypertension and angina. It delivers nifedipine via Alza s osmotic pump, a patented high-tech sustained-release (SR) formulation. Several generic companies are currently seeking FDA approval for an A/B substitute using low-tech SR formulations. The generic companies claim that they are not infringing Pfizer s patent estate, which includes ... 

Abrahamsson, B., M. Alpsten, B. Bake, U. E. Jonsson, M. Lepkowska-Eriksson, and A. Larsson. (1998b). Drug absorption from nifedipine hydrophilic matrix extended-release (ER) tablet—Comparison with an osmotic pump tablet and effect of food./. Controlled Release 52 301-310. 

Example 19.2-1 Steady delivery of a water-insoluble drug We want to develop a device to deliver nifedipine, a calcium channel blocker with extremely low water solubility (<10 ppm). We need to deliver the drug as a 0.006 g/cm suspension at a rate of 25 pg/hr using an osmotic pump functioning like that shown in Fig. 19.2-1. The osmotic pump uses a brine whose saturated concentration is 10 M. If the semipermeable membrane that you plan to use has permeance (P//) of 1.4 10" cm/sec, what membrane area will we need ... 

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