Diltiazem sustained-release

Isoptin SR, Verelan) 180-480 Amlodipine (Norvasc) 5-10 Nifedipine long-acting (Adalat CC, Procardia XL) 30-90 Diltiazem sustained-release (Cardizem SR) 180-360 Diabetes... 

Yu, K., etal., Optimization of sustained-release diltiazem formulations in man by irewtofe/in vivo correlation,J. Pharm. Pharmacol., 50, 845, 1998. 

Wilding, I., Hardy, J., Maccari, M., Ravelli, V., and Davis, S., Scintigraphic and pharmacokinetic assessment of a multiparticulate sustained release formulation of diltiazem, International Journal of Pharmaceutics, Vol. 76, No. 1-2, 1991, pp. 133-143. 

Follonier, N. Doelker, E. Cole, E.T. Various ways of modulating the release of diltiazem hydrochloride from hot-melt extruded sustained release pellets prepared using polymeric materials. J. Controlled Release 1995, 36, 243-250. 

Morimoto S, Sasaki S, Kiyama M, Hatta T, Moriguchi J, Miki S, Kawa T, Nakamura K, Itoh H, Nakata T, Takeda K, Nakagawa M. Sustained-release diltiazem overdose. J Hum Hypertens 1999 13(9) 643. ... 

Quispel R, Baur HJ. Tentamen suicidii door diltiazem met gereguleerde afgifte. [Attempted suicide with sustained release diltiazem.] Ned Tijdschr Geneeskd 2001 145(19) 918-22. 

Although primarily used as a suspending agent, xanthan gum has also been used to prepare sustained-release matrix tablets. ° Controlled-release tablets of diltiazem hydrochloride prepared using xanthan gum have been reported to sustain the drug release in a predictable manner and the drug release profiles of these tablets were not affected by pH and agitation rate.< >... 

The exception to this is the case of some sustained-release preparations where the release properties of different brands may vary (for example modified-release diltiazem or theophylline preparations). In these cases, it is usual for patients to be maintained on one particular brand to prevent fluctuations in plasma concentration. See the British National Formulary for further details. 

Diltiazem hydrochloride is a calcium ion influx inhibitor (slow channel blocker or calcium antagonist). It has generally been indicated for the treatment of angina and, more recently (2), hypertension. Diltiazem hydrochloride is a potent dilator of coronary arteries and has been shown to increase exercise tolerance in man. It is available for dosing as immediate release tablets and as extended or sustained release capsules and is usually well-tolerated. While some adverse reactions have been reported during diltiazem hydrochloride therapy, it is generally considered to be well-tolerated. In most cases, no causal relationship between the events and diltiazem hydrochloride use has yet to be established (1). 

Uekama, K., Hirashima, N., Horiuchi, Y. etal Ediylated p-cyclodextrins as hydrophobic drug carriers sustained release of diltiazem in die rat. J. Pharm. Sci. 1987, 76, 660-661. 

Yu K, Gebert M, Altaf SA, Wong D, Friend DR. Optimisation of sustained-release diltiazem formulations in man by use of an in vitro/in vivo correlation. J Pharm Pharmacol 1998 50 845-850. 

K. Murata, H. Yamahara, M. Kobayashi, K. Noda, and M. Samejima, Pharmacokinetics of an oral sustained-release diltiazem preparation. J Pharm Sci 78 960-963 (1989). 

K. Murata and K. Noda, Pharmacokinetic analysis of an oral sustained-release diltiazem preparation using multifraction absorption models. Pharm Res 10 757-762 (1993). 

There are approximately a dozen calcium channel antagonists marketed in the United States for the treatment of hypertension, certain dysrhythmias, and some forms of angina (see Chaps. 13,15, and 17). The calcium channel blockers are classified by their chemical structure as phenylalkylamines (e.g., verapamil), benzothiapines (e.g., diltiazem), and dihydropyridines (e.g., amlodipine, felodipine, nicardipine, and nifedipine). Several of these agents, namely, diltiazem, nicardipine, nifedipine, and verapamil, are formulated as sustained-release oral dosage forms or have a slow onset of action and longer half-life (e.g., amlodipine " ), allowing once-daily administration. 

Morimoto S, Sasaki S, Kiyama M, et al. Sustained-release diltiazem overdose. J Hum Hypertens 1999 13 643-644. 

Many different formulations of verapamil and diltiazem are currently available (see Table 13-5). Although certain sustained-release verapamil and diltiazem products may contain the same active drug (i.e., Calan SR and Verelan both contain verapamil), they are usually not AB rated by the FDA as interchangeable on a milligram-per-milligram basis because of different biopharmaceutical release mechanisms. 

Bialer, M. Hadad, S. Golomb, G. Barel, S. Samara, E. Abu Salach, O. Berkman, N. Danenberg, H.D. Ben David, J. Caron, D. Pharmacokinetic analysis of two new sustained-release products of diltiazem designed for twice- and once-daily treatment. Biopharm.Drug Dispos., 1994, 15, 45-52... 

Boucher, S. Varin, F. Theoret, Y Du Souich, P Caille, G. High-performance Uquid chromatographic method for the determination of diltiazem and two of its metabolites in human plasma application to a new sustained release formulation. J.Pharm.Biomed.Anal., 1989, 7, 1925—1930 Caille, G. Dube, L.M. Theoret, Y Varin, R Mousseau, N. McGilveray, I.J. Stability study of diltiazem and two of its metabolites using a high performance liquid chromatographic method. Biopharm.Drug Dispos., 1989, 10, 107-114... 

Diltiazem has a first-pass effect, which reduces bioavailablity. Bioavailability may be improved, however, with the use of the sustained release form of the drug. 

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