Department of Bioengineering, Stanford University, Stanford, 94305, USA.
Department of Biochemistry, Stanford University, Stanford, 94305, USA.
Pharm Res. 2022 Nov;39(11):2721-2728. doi: 10.1007/s11095-022-03367-y. Epub 2022 Aug 17.
While excipients are often overlooked as the "inactive" ingredients in pharmaceutical formulations, they often play a critical role in protein stability and absorption kinetics. Recent work has identified an ultrafast absorbing insulin formulation that is the result of excipient modifications. Specifically, the insulin monomer can be isolated by replacing zinc and the phenolic preservative metacresol with phenoxyethanol as an antimicrobial agent and an amphiphilic acrylamide copolymer excipient for stability. A greater understanding is needed of the interplay between excipients, insulin association state, and stability in order to optimize this formulation. Here, we formulated insulin with different preservatives and stabilizing excipient concentrations using both insulin lispro and regular human insulin and assessed the insulin association states using analytical ultracentrifugation as well as formulation stability. We determined that phenoxyethanol is required to eliminate hexamers and promote a high monomer content even in a zinc-free lispro formulation. There is also a concentration dependent relationship between the concentration of polyacrylamide-based copolymer excipient and insulin stability, where a concentration greater than 0.1 g/mL copolymer is required for a mostly monomeric zinc-free lispro formulation to achieve stability exceeding that of Humalog in a stressed aging assay. Further, we determined that under the formulation conditions tested zinc-free regular human insulin remains primarily hexameric and is not at this time a promising candidate for rapid-acting formulations.
虽然辅料通常被视为药物制剂中的“非活性”成分而被忽视，但它们在蛋白质稳定性和吸收动力学中常常起着关键作用。最近的研究已经确定了一种超快速吸收的胰岛素制剂，这是辅料修饰的结果。具体来说，可以通过用苯氧乙醇代替锌和酚类防腐剂间甲酚作为抗菌剂，并用两亲性丙烯酰胺共聚物辅料来稳定胰岛素单体，从而分离出胰岛素单体。为了优化这种配方，需要更深入地了解辅料、胰岛素结合状态和稳定性之间的相互作用。在这里，我们使用不同的防腐剂和稳定的辅料浓度来配制胰岛素，包括胰岛素赖脯肽和常规人胰岛素，并使用分析超速离心以及制剂稳定性来评估胰岛素的结合状态。我们发现，即使在无锌赖脯肽配方中，也需要苯氧乙醇来消除六聚体并促进高单体含量。基于聚丙烯酰胺的共聚物辅料的浓度与胰岛素稳定性之间也存在浓度依赖性关系，其中需要大于 0.1 g/mL 的共聚物浓度，才能使无锌赖脯肽制剂在应激老化试验中达到超过 Humalog 的稳定性，该制剂主要是单体。此外，我们确定在测试的配方条件下，无锌常规人胰岛素主要仍然是六聚体，目前不是快速作用制剂的有前途的候选物。
