ABSTRACT
This paper explores the statistical distribution characteristics of coating film thickness, so as to present a new method for determining coating endpoint based on 3σ criterion and logic regression. Firstly, the spectrum and thickness of 4 batch samples were collected. Secondly, the spectral range of normal products was obtained by 3σ criterion, with the spectral feature NI as the number of test spectrum in the above range. Then, the model based on 3σ criterion and logic regression was built according to the best condition in K-fold cross-validation and the determined threshold of qualified rate in the coating endpoint. Finally, the qualified rate of test set samples at different time points was calculated by the above model, and the above change trend and the threshold value were combined to determine the coating endpoint. The results of KS analysis showed the distribution of thickness of the qualified products followed the normal distribution(P=0.081>0.05). The accuracy of the coating endpoint determination was as high as 100% by the model based on 3σ criterion and logic regression when the determined threshold of qualified rate was 90%. Therefore, the 3σ criterion was feasible to the research of coating eligibility. This paper reveals certain random phenomena in the coating process, and the method features a high accuracy, quick analysis and a good interpretability, which provides a reference for online detection and qualify evaluation in future.
Subject(s)
Endpoint Determination , Logic , Research Design , TabletsABSTRACT
Objective: To investigate the rat intestinal absorption kinetics of danshensu (DS) and protocatechuic aldehyde (PA) in Salviae Miltiorrhizae Radix et Rhizoma extract. Methods: In situ single pass intestinal perfusion model was employed to investigate the effects of perfusion rate, perfusion solution pH value, bile duct ligation, drug concentrations, absorption sites and P-glycoprotein (P-gp) on absorption of DS and PA, and perfusion volume was corrected by gravimetric method. Meanwhile, the concentration of DS and PA in the perfusate were determined by HPLC. Results: The drug absorption constant (Ka) and apparent absorption coefficient (Papp) of DS and PA increased linearly along with the increasing perfusion rates among the ranges of 0.2-0.8 mL/min. pH value of perfusion solution affected drug absorption (P < 0.05), Ka and Papp of DS and PA decreased with increasing pH value at pH values of 7.4, 6.8, and 5.5. And at pH value of 5.5 and 6.8, the absorption had no significant difference, but there was significant difference at pH value between 5.5 and 7.4 (P < 0.05). There was no significant difference in Ka and Papp value between bile duct ligation group and no ligation group. At different absorption sites, K a and Papp of DS in the duodenum, jejunum, ileum, and colon sequence have a downward trend, but not for PA, while PA could be absorbed well at all intestinal segments. In the drug concentrations of 0.8, 1.5, and 2.2 mg/mL, Ka, and Papp of DS decréased with higher concentrations, and PA absorption parameter has non-obvious changes. There was no significant difference in Ka and Papp between the presence of P-gp inhibitor and no P-gp inhibitor. Conclusion: Perfusion rate and pH value have significant influence on absorption of DS and PA. Two water-soluble ingredients could be absorbed at all intestinal segments and DS has better absorption at former intestinal segments. The concentration of the extract has no influence on its absorption parameters of PA, which preliminarily demonstrates that PA is absorbed by passive diffusion mechanism. However, absorption of DS is affected by concentration, indicating that in addition to passive diffusion, it may also have active absorption or facilitation diffusion in absorption process of DS. Moreover, two ingredients are not affected by P-gp efflux.