Open AccessCalcium antagonists in cardiology: Update on sustained‐release drug delivery systems
Author(s) -
Michelson Eric L.
Publication year - 1991
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.4960141203
Subject(s) - medicine , pharmacology , verapamil , pharmacokinetics , drug , dosing , pharmacodynamics , calcium , drug delivery , extended release , immediate release , nifedipine , dosage form , chemistry , organic chemistry
One limitation of standard oral formulations of calcium antagonists has been the need for multiple daily dosing. Sustained‐release dosage forms permit simpler regimens and a smoother therapeutic effect. Differences in drug pharmacokinetic and pharmacodynamic properties have led to development of several sustained‐release delivery systems. Three major types are available: the osmotic pump, coated pellet, and slow‐dissolving material released from a matrix. Each is currently utilized with specific calcium antagonists. The osmotic pump system with nifedipine (Procardia XL, Pfizer) allows once‐daily dosing as well as improvements in certain side effects. Verapamil is available in formulations employing dissimilar release systems. The original sustained‐action products (Calan SR, Searle; Isoptin SR, Knoll) utilize a matrix system; a subsequent product (Verelan; Lederle, Wyeth‐Ayerst, A. H. Robins) utilizes timed‐release pellets. Importantly, clinical efficacy appears to be maintained with these several drugs and formulations for their approved indications. Although a specific formulation may alter the absorption, metabolism, excretion, and blood levels of a drug, it does not alter basic drug properties. Thus, the major impact of sustained‐release drug delivery system lies in potential compliance improvement and possible reduction of side effects related to serum drug profiles.