Bhargava K, Ando H Y
Department of Pharmaceutics, Philadelphia College of Pharmacy and Science, Pennsylvania 19104.
Pharm Res. 1992 Jun;9(6):776-81. doi: 10.1023/a:1015855622459.
A method of immobilizing urokinase on albumin microspheres has been developed. Laser scattering, which was used to follow particle size from the initial emulsification stage to the final aqueous resuspension of the microsphere stage, showed that particle coalescence and crosslinking were critical parameters in manufacturing the microspheres. Chemical dehydration with 2,2-dimethoxypropane was used to convert an albumin emulsion into an albumin suspension and to reduce coalescence. An optimal amount of dehydrant produced 0.3-micron particles which resisted a 50 degrees C temperature challenge. Since oil/glutaraldehyde emulsion resulted in large particles with no urokinase activity, the cross-linking concentration of glutaraldehyde was reduced by solubilizing 25% (w/v) glutaraldehyde in the oil phase with n-propanol. A concentration of 0.015% (v/v) glutaraldehyde effectively immobilized urokinase and stabilized albumin microspheres. Amidolytic activity using the specific chromogenic substrate for urokinase, S-2444, showed that enzyme activity could be retained during this glutaraldehyde cross-linking.
已开发出一种将尿激酶固定在白蛋白微球上的方法。激光散射用于跟踪从微球初始乳化阶段到最终水相重悬阶段的粒径，结果表明颗粒聚结和交联是制造微球的关键参数。使用2,2 - 二甲氧基丙烷进行化学脱水，将白蛋白乳液转化为白蛋白悬浮液并减少聚结。适量的脱水剂可产生能耐受50℃温度挑战的0.3微米颗粒。由于油/戊二醛乳液会产生无尿激酶活性的大颗粒，因此通过用正丙醇将25%（w/v）戊二醛溶解在油相中，降低了戊二醛的交联浓度。0.015%（v/v）的戊二醛浓度可有效固定尿激酶并稳定白蛋白微球。使用尿激酶特异性显色底物S - 2444的酰胺水解活性表明，在此戊二醛交联过程中酶活性能够得以保留。
