Development and Validation of a Stability-indicating Capillary Zone Electrophoretic Method for the Assessment of Entecavir and Its Correlation with Liquid Chromatographic Methods

Abstract

A stability-indicating capillary zone electrophoresis (CZE) method was validated for the analysis of entecavir in pharmaceutical formulations, using nimesulide as an internal standard. A fused-silica capillary (50 μm i.d.; effective length, 40 cm) was used while being maintained at 25 C; the applied voltage was 25 kV. A background electrolyte solution consisted of a 20 mM sodium tetraborate solution at pH 10. Injections were performed using a pressure mode at 50 mbar for 5 s, with detection at 216 nm. The specificity and stability-indicating capability were proven through forced degradation studies, evaluating also the in vitro cytotoxicity test of the degraded products. The method was linear over the concentration range of 1 -200 μg mL -1 (r 2 = 0.9999), and was applied for the analysis of entecavir in tablet dosage forms. The results were correlated to those of validated conventional and fast LC methods, showing non-significant differences (p > 0.05).

Validation of a stability-indicating micellar electrokinetic capillary method for the assessment of febuxostat and its correlation with the reversed-phase LC method

“…9 Capillary electrophoresis (CE) has expanded its scope as a powerful analytical technique for pharmaceutical analysis allowing the determination of the active pharmaceutical ingredients and their impurities, with some advantages related to the existing methodologies. [10][11][12][13][14][15] Development of a stability-indicating method using the approach of stress testing as determined by the ICH guideline 16 is highly recommended for the quantitative analysis of pharmaceutical formulations. The method must be able to separate febuxostat from its potential impurities and degradation products, and validate as recommended.…”

LC–MS/MS method for the characterization of the forced degradation products of Entecavir

“…ETV was also determined in dosage form by HPLC and spectrophotometry . Dalmora et al have studied its forced degradation by CZE . However, neither the extent of degradation nor the characterization of degradation products was reported.…”

Enantiopurity analysis of new types of acyclic nucleoside phosphonates by capillary electrophoresis with cyclodextrins as chiral selectors

“…A mixture of nucleosides (guanosine, thymidine, adenosine, cytidine, uridine) and thymine was separated by CEC in porous‐layered open tubular capillaries in alkaline borate buffers, pH 8.5–10.5 . The stability of entecavir, cyclopentyl guanosine analog, in pharmaceutical formulations was monitored by using a validated CE method using 20 mM sodium tetraborate buffer, pH 10.0, as BGE, and nimesulide as internal standard . The CE separation of 6‐mercaptopurine and 6‐methylmercaptopurine in BGE consisting of 100 mM 3‐(cyclohexylamino)‐1‐propanesulfonic acid titrated by triethylamine to pH 11.2 with addition of 10% of methanol has become a methodic basis for screening of thiopurine ( S )‐methyltransferase enzyme activity (methylation of thiopurine drugs used for treatment of leukemia and autoimmune disorders) in human erythrocytes .…”