Water-soluble drugs nifedipine

Portero A, Remunanlopez C, Vilajato JL. Effects of chitosan and chitosan glutamate enhancing the dissolution properties of the poorly water soluble drug nifedipine. Int J Pharm 1998 175 75-84. 

W. Yang and M. M. de Villiers. The solubilization of the poorly water soluble drug nifedipine by water soluble 4-sulphonic calix[n]arenes. Eur. J. Pharm. Biopharm., 58, 629-36 (2004)... 

CyD, HCO-60 and HPCs can serve as a modified-release carrier of nifedipine and can be applied to other poorly water-soluble drugs with short elimination half-lives. 

We describe below the use of halloysite nanotubules for entrapment and the subsequent release of three drugs Nifedipine (anti-anginal), Furosemide (anti-hypertension and diuretic), and Dexamethasone (synthetic corticosteroid). To increase the loading of these poorly soluble drugs in the tubules, we loaded them into a water-alcohol co-solvent solution (0, 10, and 50% ethanol). 

Suzuki and Sunada " also prepared solid dispersions of nifedipine with other combined carriers using a fusion (melt) method. The combined carriers were nicotinamide and four different water-soluble polymers hydroypropyl methylcellulose (HPMC), polyvinylpyrrolidone (PVP), partially hydrolyzed polyvinyl alcohol (PVA), and pullulan. HPMC, PVP, and PVA dissolved in the melt of nicotinamide and were effective in the amorphous formation of nifedipine in solid dispersions. In dissolution studies, the drug concentration... 

Research continues into other agents, apart from surfactants (which are discussed in Chapter 6), which can enhance the solubility of dmgs. The calixarenes are another type of host, existing in a cup-shape in a rigid conformation. The 4-sulfonic calix[n]arenes can form host-guest type interactions with drugs such as nifedipine, a poorly water soluble agent, seen in Fig. 5.9. 

The core may be a water-soluble polymer, an inert salt or, as in the case of metoprolol fumarate, the drug itself, whose saturated solution has an osmotic pressure of 32.5 atm. The osmotic tablet of nifedipine is described in detail in Fig. 8.38, which shows the semipermeable cellulose acetate coating, the swellable hydrogel layer of polyoxyethylene glycol and hydroxypropylmethylcellulose (HPMC) and the dmg chamber containing nifedipine in HPMC and PEG. 

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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