Consistency evaluation method for Lianhua Qingwen Capsule based on microcalorimetry / 中草药

ABSTRACT

Objective: To study the effect of Lianhua Qingwen Capsule (LQC) on the growth and metabolism of Pseudomonas aeruginosa and to establish a new method to evaluate the consistency of LQC. Methods: The power-time curves and corresponding thermodynamic parameters such as appearance time (T), total heat output (Q), maximum power output (P), and growth rate constant (k) of P. aeruginosa were determined by microcalorimetry. The regression analysis was carried out with T, P, Q, and k as parameters, and the optimal parameters were selected according to the correlation coefficient to calculate the antibacterial effective rate. The effects of 11 batches of LQC and specially treated LQC samples on growth and metabolism of P. aeruginosa were determined by an index antibacterial effective rate to evaluate the antibacterial activity of LQC. Results: LQC had obvious inhibitory effect on P. aeruginosa in the range of 10.00 to 47.68 mg/mL, and the bacteriostatic efficacy and dosage of LQC had good correlation. By regression analysis, it was found that T was the best parameter in the four thermodynamic parameters, r = 0.990. The change of this parameter could directly evaluate the effect of LQC on the growth and metabolism of P. aeruginosa, with good stability. The appearance time was selected as a parameter to calculate its antibacterial effective rate (E). The results showed that there was no significant difference in E of different batches of LQC samples. And the E value was significantly changed when the sample was placed in a humid/high temperature environment. Conclusion: The microcalorimetric method can be used to evaluate the antibacterial activity and the quality consistency of LQC capsule, which has the high precision and good accuracy. The study has provided a new method to evaluate the quality consistency of TCM.