Quantitative and Qualitative Analytical Method Development for Analysis of Herbal Medicinal Extract (CP001) for Atopic Dermatitis

Abstract

CP001 is a standardized herbal mixture of Rehmannia glutinosa, Houttuynia cordata, Rubus coreanus and Betula platyphylla. CP001 is currently under development as a therapeutic agent for the treatment of atopic dermatitis (AD). In the present study, we developed rapid and optimized quantitative and qualitative high-performance liquid chromatography (HPLC) method for analysis of CP001. The developed chromatographic method with UV detection was designed and validated for quantitative and pattern recognition analysis for the quality evaluation and quality control of CP001. The validation data indicated for chemical profiling of CP001. In 2nd part, LC/MS/MS method was developed for pharmacokinetic analysis of catalpol after oral administration of CP001 to rats; and its pharmacokinetic parameters were calculated. The effect of CP001 on cytochrome P450 (CYP) enzyme-related drug metabolism was investigated in vitro to evaluate the potential for herb-drug interactions. CP001 seemed to slightly inhibit some CYP (1A2, 2A6, 3A4, 2C9, 2C19, 2D6) isozymes, but the IC50 values for all tested CYP isozymes were greater than 100 μg/mL. Furthermore, CP001 did not exhibit time-dependent CYP inhibitory activities, indicating that it does not act as a mechanism-based in-activator of CYP enzymes. So it is concluded that the effects of CP001 on CYP isozyme activities were negligible at the concentrations tested. Therefore, the likelihood of herbal mixture-drug interactions is considered minimal for CP001.