Taylor M J, Tanna S, Taylor P M, Adams G
Department of Pharmaceutical Sciences, De Montfort University, Leicester, UK.
J Drug Target. 1995;3(3):209-16. doi: 10.3109/10611869509015947.
A self regulating delivery device, responsive to glucose, has been shown to operate successfully in vitro. This comprises a gel membrane which determines the delivery rate of insulin from a reservoir. The gel consists of a synthetic polysucrose and the lectin, concanavalin A. The mechanism is one of displacement of the branched polysaccharide from the lectin receptors by incoming glucose. The gel loses its high viscosity as a result but reforms on removal of glucose, thus providing the switch controlling the drug diffusion rate. The drug does not require to be chemically modified and thus the device is adaptable to other anti-hyperglycaemic drugs. However, results here indicate that the molecular weight of the solute may be an important parameter. Others include path length, gel formulation and temperature. It had been hypothesised that the reversal might be improved by the use of a non-aqueous reservoir of insulin. However, with the use of insulin, the switching off was found to be superior to that found with other test solutes used in previous studies, irrespective of the reservoir solvent. The advantages in the use of the non-aqueous system include, however, more reproducibility in the magnitude of response and a reduced temperature sensitivity.
一种对葡萄糖有反应的自调节给药装置已在体外成功运行。它包括一个凝胶膜，该凝胶膜决定胰岛素从储存器中的释放速率。凝胶由合成聚蔗糖和凝集素伴刀豆球蛋白A组成。其机制是进入的葡萄糖将支链多糖从凝集素受体上置换下来。结果凝胶失去其高粘度，但在葡萄糖去除后又重新形成，从而提供控制药物扩散速率的开关。药物无需进行化学修饰，因此该装置适用于其他抗高血糖药物。然而，这里的结果表明溶质的分子量可能是一个重要参数。其他参数包括路径长度、凝胶配方和温度。曾有人假设，使用胰岛素的非水储存器可能会改善这种逆转情况。然而，使用胰岛素时，无论储存器溶剂如何，发现关闭效果都优于先前研究中使用的其他测试溶质。不过，使用非水系统的优点包括反应幅度的重现性更高以及温度敏感性降低。
