A multi-evaluating strategy for Weikangling capsules: Chemical profiling, fingerprinting combined with quantitative...

Weikangling capsules (WKLCs), a Chinese patent medicine consisting of 8 Chinese drugs, have been widely used in clinic to treat gastrointestinal diseases for more than 30 years. The current "Chinese Pharmacopoeia" (2020 Edition, ChP2020) uses paeoniflorin content (≥ 1.0 mg per capsule) as the standard of quality control, but it is insufficient to evaluate the overall quality of WKLCs. An efficient and economic method for quality control is urgently needed to ensure the quality consistency and clinical effects of WKLCs. Herein, a systematic and reliable method for the rapid analysis of chemical components in WKLCs was established for the first time based on ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). A total of 115 components covering 7 herbs in WKLCs were preliminarily identified by comparison with standard substances or literature. To evaluate the quality of 26 batches of WKLCs, a new method of fingerprinting combined with quantitative analysis was established, and 16 common peaks were selected to establish the fingerprint similarity model (similarity>0.90). Simultaneously, the contents of albiflorin, paeoniflorin, dactylorhin A, militarine, and glycyrrhizic acid were determined to be 0.82 ± 0.22, 2.09 ± 0.24, 1.15 ± 0.40, 3.73 ± 0.76 and 0.99 ± 0.20 mg/capsule, respectively. The transfer rates and dissolution curves of the five compounds were successfully detected in WKLCs, and the average transfer rates were 67.2%, 33.0%, 68.3%, 54.7%, and 33.7%, respectively. Notably, the dissolution profiles of different manufacturers presented remarkable differences in pH 1.2 hydrochloric acid solution. This method not only qualitatively identified the chemical components of Chinese patent medicines at the microlevel but also evaluated the quality consistency between batches at the macrolevel, which provided a comprehensive reference for the quality consistency of Chinese patent medicines between batches.