Vemuri S, Yu C D, Roosdorp N
Scios Nova, Mountain View, California 94043.
PDA J Pharm Sci Technol. 1994 Sep-Oct;48(5):241-6.
Stabilizing effect of several commonly used cryoprotectants, namely lactose, sucrose, and polyvinyl-pyrrolidone (PVP), on recombinant alpha 1-antitrypsin (rAAT) were studied. A solution of rAAT in a phosphate/citrate buffer (pH 7.0) was made with and without a given cryoprotectant and filled into small vials. The vials were frozen on shelf, at -40 degrees C in a lyophilizer. At the end of the freezing cycle, half of the batch was thawed at ambient temperature and the other half was continued to the completion of lyophilization. Sample vials taken before freezing, after thawing, and after lyophilization were analyzed for total rAAT protein, monomeric content, and elastase-inhibitory activity. Results indicated that neither freeze-and-thaw nor lyophilization caused any damage to rAAT, contrary to what was generally believed. The control formulation (i.e., without a cryoprotectant) performed as good as those containing cryoprotectants. Freezing rates and protein concentration in formulation did not influence the stability of rAAT either. Lyophilized rAAT samples retained the activity and purity during the 12 month stability period, at room temperature and 2-8 degrees C.
研究了几种常用的冷冻保护剂，即乳糖、蔗糖和聚乙烯吡咯烷酮（PVP）对重组α1-抗胰蛋白酶（rAAT）的稳定作用。在有无特定冷冻保护剂的情况下，用磷酸盐/柠檬酸盐缓冲液（pH 7.0）配制rAAT溶液，并装入小瓶中。小瓶在冻干机中于-40℃的架子上冷冻。在冷冻循环结束时，一批样品的一半在室温下解冻，另一半继续冻干至完成。对冷冻前、解冻后和冻干后的样品瓶进行总rAAT蛋白、单体含量和弹性蛋白酶抑制活性分析。结果表明，与普遍认为的相反，冻融和冻干均未对rAAT造成任何损害。对照制剂（即不含冷冻保护剂）的性能与含冷冻保护剂的制剂一样好。冷冻速率和制剂中的蛋白质浓度也不影响rAAT的稳定性。冻干的rAAT样品在室温及2-8℃的12个月稳定期内保持了活性和纯度。
