Factors Contributing to Drug Release From Enteric-Coated Omeprazole Capsules: An In Vitro and In Vivo Pharmacokinetic Study and IVIVC Evaluation in Beagle Dogs.

This study was performed to explore factors influencing the release of the proton pump inhibitor omeprazole from enteric-coated capsules in vitro and absorption in vivo in beagle dogs. Enteric-coated pellets with different enteric coating materials and coating levels were designed and prepared. All self-prepared formulations were characterized in vitro as well as in vivo and compared to the brand and generic commercial products. Evaluation of the corresponding release profiles suggested that coating material was the most critical factor. Enteric coating level determined the lag time before initiation of drug release, and subcoating level affected the drug release rate. Pharmacokinetic studies were performed in beagle dogs to further confirm the influence of formulation factors on drug absorption. Medium at pH 6.8 was a more biorelevant condition for in vitro drug release tests, although medium at pH 6.0 was better for discriminating release profiles of different formulations. A multiple level C in vitro/in vivo correlation was preliminarily established by which Tmax and Cmax of omeprazole formulations could be predicted with release parameters such as Tlag and T25. These results may facilitate quality evaluation and potentially improve the clinical efficacy of generic omeprazole products.

[Studies on chemical constituents in root of Phlomis medicinalis I].

OBJECTIVE: To study the chemical constituents in root of Phlomis medicinalis. METHOD: The compounds were isolated and repeatedly purified on macroporous resin, silica gel column chromatography, TLC and Prep-HPLC and the structures were elucidated by physico-chemical properties and NMR spectra. RESULT: Eight compounds were obtained and elucidated as 5-Hydroxy-7-methoxy-4, 6-dimethylphthalide (1), 4-hydroxymethyl-2-furaldehyde (2) and six iridoid glucosides: 6-O-acetyl-shanzhiside methyl ester (3), 8-O-acetyl-shanzhiside methyl ester (4), shanzhiside methyl ester (5), sesamoside (6), phloyoside II (7) and dehydropentstemoside (8). CONCLUSION: All the compounds were isolated from the plant for the first time and 1 and 3 were obtained from the plants of Phlomis for the first time.

[Infrared spectroscopy technology, one of the faster and more convenient methods to detect the stability of stored Niuxi].

OBJECTIVE: To detect the change of Niuxi in reserve and establish one easier method of evaluating the quality change of Niuxi. METHODS: Infrared spectroscopy and compare software were used to distinguish the different Niuxi, and simulation testing were used to observe calefactive stability. RESULTS: There were obvious difference between transmutative and normal Niuxi, and Niuxi had evident change when the temperature above 140 degrees C in the simulation testing. CONCLUSION: Infrared spectroscopy can be used to evaluae the quality stability of Niuxi. It is one tried method to provide the establishment of reserve and torrefaction conditions.

[Studies on Niuxi with the method of FT-IR spectroscopy and analyze technology auxiliary].

OBJECTIVE: To study the genuine of 32 samples of Niuxi from 14 provinces, and compare some samples stored for different time to check the change in the coures of store. METHOD: IR spectroscopy and Analyze Technology Auxiliary softeare. RESULT: The coefficient correlations had certain difference among these Niuxi from different places. They were divided into two parts if r = 0.9840 the standerd: trueborn crude drugs (r > 0.9840) and non-trueborn (r < 0.9840). And we can know the change in medicinal materials according r. CONCLUSION: The method is operated simple and determined fast; the result is reliable; repetitiveness is good.

[Study on sterols and triterpenes from the stems of Akebia quinata].

The ethanol extract from Akebia quinata was seperated by dichloromethane, n-butanol in sequence. Six compounds were isolated and identified as beta-sitosterol (I), delta(5,22) stigmasterol (II), oleanolic acid (III), hederagenin (IV), daucosterol (V), delta(5,22) stigmasterol-3-O-beta-D-glycopyranoside (VI). Compound VI was isolated from Akebia plants for the first time.