Investigation of peptide-polymer interactions in PLGA microspheres

PLGA 微球中肽-聚合物相互作用的研究

基本信息

批准号：
9346576
负责人：
STEVEN P. SCHWENDEMAN
金额：
$ 25万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-05 至 2019-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9346576
关键词：
Investigation peptide polymer interactions PLGA

项目摘要

There is a scientific gap in our current understanding of how formulation and raw material variables used to manufacture poly(lactic-co-glycolic acid) (PLGA) microspheres encapsulating peptides lead to differing levels of peptide-polymer interactions and peptide acylation during encapsulation, storage, and release in vitro and in vivo. Batch-to-batch variation and unpredictable acylation levels could lead to differences in pharmacokinetics (PK) and loss of bioequivalence of generic long-acting release (LAR) formulations seeking to mimic LAR products. Such differences in bioequivalence may lead to differences in safety and efficacy. A key factor leading to the loss of parent drug is the poorly defined interaction between the peptide and the polymer, which has been shown to be a precursor to the acylation reaction. For example, salt formation between the cationic and acylation-labile octreotide, found in the Sandostatin LAR (SLAR) microsphere product, with the ionized carboxylic acid end-groups of PLGA has been shown to be necessary for acylation to occur. We hypothesize the key underlying time-dependent factors responsible for differences in peptide-polymer interactions and acylation for microspheres of similar compositions include: (a) microclimate pH in the microspheres affecting ionization of polymer carboxylic acids necessary to bind to a cationic peptide; (b) the extent to which the polymer allows penetration of the peptide into the polymer phase, and (c) the architecture of the polymer (star vs. linear) and end-capping that affect the strength and type of intermolecular forces responsible for peptide- polymer interactions. The following tasks will be developed to test our hypothesis and close the aforementioned scientific gap: 1. Develop techniques for assessing peptide-polymer interactions and peptide acylation impurities with the reference product, SLAR; 2. Reverse engineer the composition of SLAR; 3. Create Q1/Q2 formulations for the SLAR as a function of microencapsulation conditions, and determine product attributes relative to SLAR. 4. Create microsphere formulations with virtually the same composition of SLAR but with different PLGA architecture and molecular weight, and determine product attributes; 5. Compare peptide-polymer interactions, acylation, erosion behavior and release kinetics in all formulations to identify key formulation and polymer architecture controlling differences in peptide acylation and release kinetics in vitro; and 6. Verify in vitro differences observed in Task 1 and 5 by assessing key formulations for PK after intramuscular injection and direct measurements after recovery from a novel in vivo cage model. We will apply a wide range of novel experimental approaches developed by our group over the last 20 years to interrogate the peptide-polymer interactions necessary to initiate octreotide acylation in PLGAs. We will further combine this approach with a large number of rigorous and new in vitro assays to test formulations with relevance to future regulatory guidance to generics and verify their relevance to the not yet predictable in vivo environment.

我们目前对配方和原材料变量如何习惯的理解存在科学差距生产聚（乳酸 - 乙醇酸）（PLGA）微球封装肽的微球导致水平不同在封装，存储和释放期间的肽聚合物相互作用和肽酰化体内。批次之间的变化和不可预测的酰基化水平可能导致药代动力学的差异（PK）试图模仿LAR的通用长效释放（LAR）制剂的生物等效性的丧失产品。这种生物等效性的这种差异可能导致安全性和功效的差异。一个关键因素导致父母丧失的是肽与聚合物之间的相互作用很差，而聚合物的相互作用是已被证明是酰化反应的前体。例如，阳离子之间的盐和酰基化的奥曲肽，在Sandostatin Lar（Slar）微球产物中发现，并具有离子化已经证明，PLGA的羧酸端基团对于酰化是必需的。我们假设负责肽 - 聚合物相互作用差异和相似组成的微球的酰化包括：（a）影响的微球的微气候pH值与阳离子肽结合所必需的聚合物羧酸的电离；（b）在多大程度上聚合物允许将肽渗透到聚合物相中，并且（c）聚合物的结构（恒星与线性）和终端封顶，影响负责肽的强度和类型间的强度和类型聚合物相互作用。将开发以下任务来检验我们的假设并关闭上述科学差距：1。开发用于评估肽聚合物相互作用和肽的技术参考产品SLAR的酰基化杂质； 2。反向工程SLAR的组成； 3。创建 Q1/Q2 SLAR的配方是微囊化条件的函数，并确定产物属性相对于SLAR。 4。创建具有相同组成SLAR组成的微球配方但是，具有不同的PLGA结构和分子量，并确定产品属性； 5。比较在所有制剂中配方和聚合物结构控制肽酰化和体外释放动力学的差异；和6。通过评估PK之后的PK的关键配方在任务1和5中验证体外差异从新型的体内笼模型中恢复后肌内注射和直接测量。我们将申请在过去的20年中，我们小组开发了各种新型实验方法来审问启动PLGA中诱发奥曲肽酰化所必需的肽聚合物相互作用。我们将进一步结合这种方法具有大量严格和新的体外测定法，以测试与未来的监管指导，仿制药并验证其与体内尚不可预测的相关性。