Maa Y F, Nguyen P A, Hsu S W
Genentech, Inc., South San Francisco, California 94080, USA.
J Pharm Sci. 1998 Feb;87(2):152-9. doi: 10.1021/js970308x.
Spray-drying is an attractive method for preparing fine recombinant human growth hormone (rhGH) powders if the detrimental effect of protein degradation at the air-liquid interface on the protein can be minimized. In this study, we demonstrated that rhGH degradation (insoluble and soluble aggregate formation), as the consequence of air-liquid interfacial degradation, could be prevented using the appropriate formulation. Adding polysorbate-20 surfactant into the liquid feed (with no presence of sugar protectant) significantly reduced the formation of insoluble protein aggregates, while adding the divalent metal zinc ion effectively suppressed the formation of soluble protein aggregates. The combination of the two yielded a spray-dried rhGH powder having insignificant protein degradation. Our data suggest that the two components might protect the protein through different mechanisms. Polysorbate molecules occupy the air-liquid interface of spray droplets, thereby reducing the chance for rhGH to form insoluble aggregates by surface denaturation. Two zinc ions associate with two rhGH molecules to form a dimer complex that can resist the formation of soluble protein aggregates. Characterization of spray-dried powders by scanning electron microscopy suggests that both formulation and drying conditions have a strong influence on particle morphology and shape. Overall, spherical rhGH powders of smooth surface and good biochemical quality can be prepared by spray-drying using this formulation with no addition of sugar protectant.
如果能将气液界面处蛋白质降解对蛋白质的有害影响降至最低，喷雾干燥是制备重组人生长激素（rhGH）细粉的一种有吸引力的方法。在本研究中，我们证明了通过使用合适的配方，可以防止作为气液界面降解结果的rhGH降解（不溶性和可溶性聚集体形成）。向液体进料中添加聚山梨酯-20表面活性剂（不存在糖保护剂）可显著减少不溶性蛋白质聚集体的形成，而添加二价金属锌离子可有效抑制可溶性蛋白质聚集体的形成。两者结合得到的喷雾干燥rhGH粉末蛋白质降解不明显。我们的数据表明，这两种成分可能通过不同的机制保护蛋白质。聚山梨酯分子占据喷雾液滴的气液界面，从而减少rhGH因表面变性形成不溶性聚集体的机会。两个锌离子与两个rhGH分子结合形成二聚体复合物，该复合物可抵抗可溶性蛋白质聚集体的形成。通过扫描电子显微镜对喷雾干燥粉末进行表征表明，配方和干燥条件对颗粒形态和形状有很大影响。总体而言，使用该配方且不添加糖保护剂通过喷雾干燥可制备出表面光滑且生化质量良好的球形rhGH粉末。
