title: Purity assessment of recombinant human granulocyte colony-stimulating factor in finished drug product by capillary zone electrophoresis.
abstract: Current methods for determination of impurities with different charge-to-volume ratio are limited especially in terms of sensitivity and precision. The main goal of this research was to establish a quantitative method for determination of impurities with charges differing from that of recombinant human granulocyte colony-stimulating factor (rhG-CSF, filgrastim) with superior precision and sensitivity compared to existing methods. A CZE method has been developed, optimized, and validated for a purity assessment of filgrastim in liquid pharmaceutical formulations. Optimal separation of filgrastim from the related impurities with different charges was achieved on a 50 μm id fused-silica capillary of a total length of 80.5 cm. A BGE that contains 100 mM phosphoric acid adjusted to pH 7.0 with triethanolamine was used. The applied voltage was 20 kV while the temperature was maintained at 25°C. UV detection was set to 200 nm. Method was validated in terms of selectivity/specificity, linearity, precision, LOD, LOQ, stability, and robustness. Linearity was observed in the concentration range of 6-600 μg/mL and the LOQ was determined to be 0.3% relative to the concentration of filgrastim of 0.6 mg/mL. Other validation parameters were also found to be acceptable; thus the method was successfully applied for a quantitative purity assessment of filgrastim in a finished drug product.
authors.affiliation: Agency for Medicinal Products and Medical Devices, Zagreb, Croatia.
authors.forename: Goran
authors.initials: G
authors.lastname: Benković
authors.forename: Ana
authors.initials: A
authors.lastname: Skrlin
authors.forename: Tomislav
authors.initials: T
authors.lastname: Madić
authors.forename: Zeljko
authors.initials: Z
authors.lastname: Debeljak
authors.forename: Marica
authors.initials: M
authors.lastname: Medić-Šarić
mesh_terms: D004304:Dosage Forms; D004340:Drug Contamination; D004355:Drug Stability; D019075:Electrophoresis, Capillary / Q000379:methods*; D000069585:Filgrastim; D016179:Granulocyte Colony-Stimulating Factor / Q000737:chemistry*; D016014:Linear Models; D011994:Recombinant Proteins / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004304:Dosage Forms; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D000069585:Filgrastim
keywords: Capillary zone electrophoresis; Filgrastim; Purity; Recombinant human granulocyte colony-stimulating factor; Validation