ABSTRACT
To explore the quality consistency evaluation method for multi-component traditional Chinese medicine and establish a dissolution evaluation method suitable for the characteristics of multi-component Chinese patent medicine, this study discussed the characteristics and advantages of the flow-through cell method in the dissolution evaluation of Chinese patent medicine by comparing the impact of the small cup method and the flow-through cell method on the dissolution behavior of water-soluble and lipid-soluble major active components of Danshen Tablets. Dissolution tests were performed using the small cup method as described in the 2020 edition of the Chinese Pharmacopoeia and the newly introduced flow-through cell method(closed-loop method) with water solution containing 0.5% SDS as dissolution medium. Cumulative dissolution curves of the water-soluble component salvianolic acid B and the lipid-soluble component tanshinone Ⅱ_A in Danshen Tablets were plotted, and fitting and similarity analysis of the dissolution models was conducted to identify the characteristics and advantages of the flow-through cell method. For the small cup method, 150 mL of water containing 0.5% SDS was used as the dissolution medium, with a rotation speed of 75 r·min~(-1) and a temperature of(37±0.5) ℃, and 3 mL of samples were taken at 15, 30 min, 1, 2, and 4 h, with fresh dissolution medium added at the same temperature and volume. For the flow-through cell method, a closed-loop system was used. Danshen Tablets were placed in the flow-through cell with approximately 6.7 g of glass beads, and 150 mL of water containing 0.5% SDS was used as the dissolution medium. The flow rate was set at 20 mL·min~(-1), and the temperature and sampling were the same as the small cup method. The results showed that compared with the small cup method, the flow-through cell method had stronger discriminative power and higher sensitivity in distinguishing the dissolution behavior of the two components, and could better reflect the differences in formulation quality, especially for water-insoluble lipid-soluble components. Given that there were no essential differences in the in vitro release kinetics between the two methods, the flow-through cell method could not only replace the traditional small cup method but also better guide the formulation development and identify quality issues of formulations.
Subject(s)
Salvia miltiorrhiza , Medicine, Chinese Traditional , Tablets , Water , Lipids , SolubilityABSTRACT
The degradation kinetics of chlorogenic acid (5-CQA), cryptochlorogenic acid (4-CQA), and neochlorogenic acid (3-CQA) in aqueous solution at 37 ℃ and different pH values (7.05, 7.96, 9.25) were investigated in the present work. The results indicated that 3-, 4- and 5-CQA tended to remain stable in acidic pH circumstance, and unstable in neutral and alkaline pH circumstance. With the increase of the alkalinity, the degradation of 3-, 4- and 5-CQA was increased leading to a less amount of total CQA and was satisfactorily described by the Weibull equation. Meanwhile, caffeic acid was not detected after the degradation of CQA. Moreover, the degradation of 3-CQA and 5-CQA tended to be converted to 4-CQA, and the degradation of 4-CQA tended to be converted to 3-CQA rather than 5-CQA. The comparison of the degradation kinetics parameters of 3-, 4- and 5-CQA at neutral and alkaline pH values showed that the orders of the rate constant (k) values were 4-CQA > 3-CQA > 5-CQA, while the orders of the degradation half life (t1/2) values were 4-CQA < 3-CQA < 5-CQA, indicating the orders of the stabilities of 3-, 4- and 5-CQA at 37 ℃ and neutral and alkaline pH values were 4-CQA < 3-CQA <5-CQA.
ABSTRACT
Objective: Based on the advantages of representation of herb components group clustering by characteristic spectrum integrity, to study the in vitro dissolution behavior of Daidai Flavones Dropping Pills (DFDP), and to evaluate the synchronization release situation of group clustering. Methods: Rotating basket method and HPLC characteristic spectrum were employed to evaluate the group clustering dissolution and the release characteristics of DFDP in different dissolution media (pH 1.2 hydrochloric acid solution, pH 4.5 acetic acid-sodium acetate buffer, pH 6.8 phosphate buffer, and distilled water). The single exponential, logarithmic distribution and Weibull equation model were applied to fit the dissolution curves. Results: The similarity factor (f2) of the dissolution curves of nine common peak components in characteristic spectrum of DFDP was over 50; In addition the f2 of neohesperidin and naringin was 94.86, which indicated that the group clustering of DFDP had similar dissolution curves and synchronization release characteristics. Meanwhile the dissolution mechanism of group clustering of nine common peak activity composition was following the Weibull equation model. Conclusion: The established method is simple, rapid, and stable, which provides an experimental basic for in vitro analysis and quality evaluation of DFDP.
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Objective: To establish an HPLC method for the determination of diclofenac sodium sustained-release preparations, and compare the in vitro dissolution of diclofenac sodium sustained-release capsules and tablets from different manufacturers to provide reference for the clinical reasonable medication. Methods: According to the first dissolution method described in Chinese Pharmaco-poeia (2010 edition),the dissolution of each sample was determined by HPLC and the cumulative release percentage was calculated. The dissolution parameters were fitted by Weibull-equation and the results were analyzed. Results:The HPLC method for the determi-nation of diclofenac sodium release was accurate with good reproducibility, and the dissolution parameters of different manufacturers had remarkable difference. Conclusion:The in vitro dissolution of diclofenac sodium sustained-release capsules and tablets from different manufacturers is various, which should be paid attention in the clinical use.
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Objective To compare the real-time dissolutions of 3 kinds of Simvastatin tablets used in our hospital, and provide reference information for clinical applications. Methods The dissolution rate of simvastatin tablets was deter-mined by the Chinese Pharmacopoeia 2010, and the HPLC method was used to determine the simvastatin content at the wavelength of 238 nm and the Weibull’s equation was adopted to fit the dissolution curves. The shape parameters (m) were performed statistical analysis; Using the similarity f2 as the index, compared the dissolution curve between tablets and the preparation. Results The dissolution of simvastatin tablets manufactured by the 3 manufaccturer was no less than 90% in 30 min, which comply with the national specifications. Compared with the dissolution curve of 6 tablets from the same batch, the homogenicity of samples from A was better, with poor homogenicity of tablets from B or C. There’s significant difference in the shape parameter m of tablets from B and C (P< 0.05), and there’s no significant difference in m of tablets from C and A(P>0.05). Conclusion The in vitro dissolution of the simvastatin tablets are de-termined with single point test procedures. The dissolution of the tablets from 3 manufactures comply with national specifications. However, there’s significant difference in real time dissolution of national tablets. It’s necessary to im-prove the quality of national tablets. Cautions should be taken while use in clinical practices.