Urquhart J
Fed Proc. 1980 May 15;39(7):2460-4.
Rate/duration-specified drug delivery systems have recently begun to appear as pharmaceuticals and as research tools. In both therapeutics and research, their major advantage is prevention of transient peaking of blood or tissue concentrations that are side-effect producing and potentially toxic; these peaks are the rule with conventional drench- or pulse-modes of drug administration via ordinary dosage forms. Each drug's pharmacokinetics provides the basis for specifying the rates at which its controlled delivery dosage forms should function in vivo. That is what pharmacokinetics can do for controlled drug delivery systems. What the availability of controlled drug delivery systems can do for pharmacokinetics is to make it both convenient and economical to study the steady-state pharmacokinetic behavior of a drug during chronic administration--as opposed to the much more complex and costly procedure of studying the transient pharmacokinetic behavior of the drug. Moreover, achieving and maintaining an approximately steady-state simplifies the study of spatial gradients in drug concentration in body fluids and tissues. In this fashion, advances in the technology of dosage forms, and the conversion from their static specification only by quantity to a dynamic specification by rate/duration, are strongly interdependent with both the theory and practice of pharmacokinetics.
速率/持续时间特定的药物递送系统最近已开始作为药物和研究工具出现。在治疗和研究中，它们的主要优势在于防止产生副作用和潜在毒性的血液或组织浓度出现短暂峰值；而通过普通剂型以传统灌服或脉冲模式给药时，这些峰值是常见现象。每种药物的药代动力学为确定其控释剂型在体内应发挥作用的速率提供了依据。这就是药代动力学对控释药物递送系统所能起到的作用。控释药物递送系统的可用性对药代动力学的作用在于，使研究药物在长期给药过程中的稳态药代动力学行为变得既方便又经济——这与研究药物的瞬态药代动力学行为这一更为复杂且昂贵的过程形成对比。此外，实现并维持近似稳态简化了对体液和组织中药物浓度空间梯度的研究。通过这种方式，剂型技术的进步以及从仅按数量的静态规格向按速率/持续时间的动态规格的转变，与药代动力学的理论和实践紧密相互依存。
