反相高效液相色谱法测定PELA微粒中胰岛素含量

为测定PELA微粒中胰岛素含量,建立反相高效液相色谱方法. 以Zorbax300SB-C18高效液相色谱柱分离;检测波长为220 nm;流动相组成为:V(H2O(含φ(TFA)＝0.15%))∶V(CH3CN)＝66∶34;保留时间为4.3 min. 结果在ρ(胰岛素)为10～200 μg/mL范围内,峰面积(A)与胰岛素质量浓度(ρ)成线性变化,其线性方程为:ρ=7.82×10-2A +9.88×10-2,相关系数r=0.999 95. 日内差和日间差分别为0.6%和0.7%. 当ρ(胰岛素)为60, 80和100 μg/mL时的回收率分别为(98.1±0.5)%, (99.6±1.5)%和(99.4±1.0)%(n＝6). 测得胰岛素在PELA微粒中的包封率为(56.3±3.3)%(n＝6).

Reversed-phase High Performance Liquid Chromatographic Determination of the Insulin Encapsulated in Poly-dl-lactide-poly (ethylene glycol) (PELA) Microparticles

A reversed-phase high performance liquid chromatography (RP-HPLC) method was developed for determination of insulin encapsulated in PELA microparticles. Zorbax 300SB-C18 RP-HPLC column was employed with UV detection at 220 nm. Trifluroacetic acid (TFA) was added into mobile phase to improve separate effect. The composition of the mobile phase was V(H2O(φ(TFA)=0.15%))∶V(CH3CN)=66∶34. The retention time of insulin was 4.3 min. Mass concentration (ρ) and peak area (A) had linearity from 10 to 200 μg/mL and the linear equation was ρ=7.82×10-2A+ 9.88×10-2 with correlation coefficient r=0.999 95. The intra- and inter-day relative standard deviations (RSDs) were 0.6% and 0.7%, respectively. The average recoveries (mean±SD) of the three groups (ρ(insulin) =60, 80, 100 μg/mL, respectively) were (98.1±0.5)%, (99.6±1.5)% and (99.4±1.0)%, respectively (n=6). The encapsulation efficiency (mean±SD) of insulin was (56.3±3.3)% (n=6).