ABSTRACT
A pre-Ultraperformance Liquid Chromatography (UPLC) column derivatization procedure was developed for thesimultaneous quantification of essential amino acids (EAAs) in the solid oral dosage pharmaceutical formulation.This analytical procedure has been validated with the help of the concept of total error. The total error approach (thecombination of systematic and random error) is a decision-making tool for ensuring the performance of the method.Fluorenylmethyloxycarbonyl chloride was used as a derivatization reagent. The amino acid derivatives were separatedon a C18 column (internal diameter 2.1 × 100 mm, 1.6 µm) by gradient elution with 0.1% trifluoroacetic acid andacetonitrile:water (90:10, v/v), respectively, as mobile phase A and B. About 10 EAAs could be detected at 265 nm in35 minutes with a flow rate of 0.25 ml/min. The linearity range of each amino acid was between 0.1 and 1.0 mg/ml.The accuracy and risk profiles were considered acceptable across the range. The precolumn derivatization procedureand the concept of the validation of total error could be used as an appropriate strategy to demonstrate the suitabilityof the analytical procedure for the separation and evaluation of EAA in solid oral dosage formulations.
ABSTRACT
Coptis chinensis (Huanglian) is a commonly used traditional Chinese medicine (TCM) herb and alkaloids are the most important chemical constituents in it. In the present study, an isocratic reverse phase high performance liquid chromatography (RP-HPLC) method allowing the separation of six alkaloids in Huanglian was for the first time developed under the quality by design (QbD) principles. First, five chromatographic parameters were identified to construct a Plackett-Burman experimental design. The critical resolution, analysis time, and peak width were responses modeled by multivariate linear regression. The results showed that the percentage of acetonitrile, concentration of sodium dodecyl sulfate, and concentration of potassium phosphate monobasic were statistically significant parameters (P < 0.05). Then, the Box-Behnken experimental design was applied to further evaluate the interactions between the three parameters on selected responses. Full quadratic models were built and used to establish the analytical design space. Moreover, the reliability of design space was estimated by the Bayesian posterior predictive distribution. The optimal separation was predicted at 40% acetonitrile, 1.7 g·mL(-1) of sodium dodecyl sulfate and 0.03 mol·mL(-1) of potassium phosphate monobasic. Finally, the accuracy profile methodology was used to validate the established HPLC method. The results demonstrated that the QbD concept could be efficiently used to develop a robust RP-HPLC analytical method for Huanglian.