Asmus Lutz R, Grimshaw John P A, Richle Philipp, Eicher Barbara, Urech David M, Gurny Robert, Möller Michael
School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Quai Ernest-Ansermet 30, CH-1211 Geneva, Switzerland.
ESBATech - A Novartis Company, Wagistrasse 21, CH-8952 Zürich-Schlieren, Switzerland.
Eur J Pharm Biopharm. 2015 Sep;95(Pt B):250-60. doi: 10.1016/j.ejpb.2015.02.007. Epub 2015 Mar 14.
Sustained-release formulations of a single-chain anti-VEGF-A antibody fragment were investigated in vitro toward their potential use for intravitreal applications. The hydrophobic polyester hexylsubstituted poly(lactic acid) (hexPLA) was selected as the sustained-release excipient for its biodegradability and semi-solid aggregate state, allowing an easy and mild formulation procedure. The lyophilized antibody fragment ESBA903 was micronized and incorporated into the liquid polymer matrix by cryo-milling, forming homogeneous and injectable suspensions. The protein showed excellent compatibility with the hexPLA polymer and storage stability at 4°C for 10 weeks. Additionally, hexPLA shielded the incorporated active substance from the surrounding medium, resulting in a better stability of ESBA903 inside the polymer than after its release in the buffer solution. Formulations of ESBA903 with hexPLA having drug loadings between 1.25% and 5.0% and polymer molecular weights of 1500 g/mol, 2500 g/mol, 3500 g/mol and 5000 g/mol were investigated regarding their in vitro release. All formulations except with the highest molecular weight formed spherical depots in aqueous buffer solutions and released the antibody fragment for at least 6-14 weeks. The polymer viscosity derived from the molecular weight strongly influenced the release rate, while the drug loading had minor influence, allowing customization of the release profile and the daily drug release. Size exclusion chromatography and SDS-PAGE revealed that the antibody fragment structure was kept intact during incorporation and release from the liquid matrix. Furthermore, the released protein monomer maintained its high affinity to human VEGF-A, as measured by surface plasmon resonance analysis. Formulations of ESBA903 in hexPLA meet the basic needs to be used for intravitreal sustained-release applications in age-related macular degeneration treatment.
研究了单链抗VEGF-A抗体片段的缓释制剂在玻璃体内应用的潜在用途。疏水性聚酯己基取代聚乳酸（hexPLA）因其生物可降解性和半固体聚集状态被选为缓释辅料，使得制剂过程简便温和。冻干的抗体片段ESBA903经微粉化处理，并通过低温研磨掺入液态聚合物基质中，形成均匀且可注射的悬浮液。该蛋白质与hexPLA聚合物表现出优异的相容性，在4°C下可稳定储存10周。此外，hexPLA可保护包封的活性物质免受周围介质的影响，使得ESBA903在聚合物内部比在缓冲溶液中释放后具有更好的稳定性。研究了ESBA903与hexPLA的制剂，其载药量在1.25%至5.0%之间，聚合物分子量分别为1500 g/mol、2500 g/mol、3500 g/mol和5000 g/mol，考察了它们的体外释放情况。除分子量最高的制剂外，所有制剂在水性缓冲溶液中均形成球形贮库，并释放抗体片段至少6 - 14周。由分子量得出的聚合物粘度对释放速率有强烈影响，而载药量影响较小，这使得可以定制释放曲线和每日药物释放量。尺寸排阻色谱和SDS-PAGE分析表明，抗体片段结构在掺入和从液态基质中释放过程中保持完整。此外，通过表面等离子体共振分析测定，释放的蛋白质单体对人VEGF-A仍保持高亲和力。ESBA903在hexPLA中的制剂满足了在年龄相关性黄斑变性治疗中用于玻璃体内缓释应用的基本需求。
