The pharmacokinetics and relative bioavailability were studied in 18 healthy volunteers. A single oral dose of 150 mg irbesartan capsule (test) or tablet (reference) was given to each volunteer according to a randomized 2-way crossover study. The concentrations in plasma were determined by HPLC-UV method. The main parameters of irbesartan capsules were: Cmax: 1.502 +/- 0.295 micrograms/ml, tmax: 1.44 +/- 0.34 h, t 1/2: 20.21 +/- 14.71 h, AUC0-t: 11.087 +/- 3.443 micrograms/ml-1.h. The relative bioavailability of capsule to tablet was (101.4 +/- 28.9)%. The results of statistical analysis showed that two formulations were bioequivalent.
Biological Availability ; Biphenyl Compounds/blood ; Biphenyl Compounds/*pharmacokinetics ; Capsules ; Cross-Over Studies ; Receptors, Angiotensin/*antagonists & inhibitors ; Tablets ; Tetrazoles/blood ; Tetrazoles/*pharmacokinetics

OBJECTIVETo study the transport mechanism of honokiol in Caco-2 cell model.

METHODThe analysis was performed on a Kromasil 100-5 C18 column (4.5 mm x 250 mm, 5 microm) eluted with acetonitrile-water (70: 30) as mobile phase. The detection wavelength was set at 203 nm. Two-way transport of honokiol was studied by using Caco-2 cell model, and the effects of time, drug concentration, inhibitor, pH, temperature on the transport of honokiol was investigated. The drug concentrations were determined by high performance liquid chromatography(HPLC) and used to calculate the apparent permeability coefficient.

RESULTThe standard curve of honokiol was Y = 24 044X - 3 763.6 (r = 0.999 8), and the detection limit was 0.04 micromol x L(-1). In Caco-2 cell model, the transport amounts from the top side to the base side of were more than that from the base side to the top side under the same concentration. The transport amounts increased with time both in AP --> BL and BL --> AP directions. Verapamil could improve the transport amounts of AP --> BL. There were no effects of pH on the transport of AP --> BL. Both in AP --> BL and BL --> AP directions, the transport showed temperature dependence.

CONCLUSIONHonokiol is transported through the intestinal mucosa via a passive diffusion mechanism primarily, coexisting with a carrier-mediated transport, at the same time effected by P-gp.

Biological Transport ; Biphenyl Compounds ; analysis ; pharmacokinetics ; Caco-2 Cells ; Chromatography, High Pressure Liquid ; methods ; Diffusion ; Humans ; Lignans ; analysis ; pharmacokinetics ; Permeability

The pharmacokinetics and relative bioavailability were studied in 18 healthy volunteers. A single oral dose of 150 mg irbesartan capsule (test) or tablet (reference) was given to each volunteer according to a randomized 2-way crossover study. The concentrations in plasma were determined by HPLC-UV method. The main parameters of irbesartan capsules were: Cmax: 1.502 +/- 0.295 micrograms/ml, tmax: 1.44 +/- 0.34 h, t 1/2: 20.21 +/- 14.71 h, AUC0-t: 11.087 +/- 3.443 micrograms/ml-1.h. The relative bioavailability of capsule to tablet was (101.4 +/- 28.9)%. The results of statistical analysis showed that two formulations were bioequivalent.
Adult ; Angiotensin Receptor Antagonists ; Biological Availability ; Biphenyl Compounds ; blood ; pharmacokinetics ; Capsules ; Cross-Over Studies ; Humans ; Male ; Tablets ; Tetrazoles ; blood ; pharmacokinetics

Bicyclol with benzyl alcohol structure, is a poorly water-soluble drug, used for the treatment of chronic hepatitis B. To increase the drug solubility and oral bioavailability, a Bicyclol-phospholipid complex was studied on its preparation, formation mechanism, and the influence on drug physicochemical properties and oral absorption. The complex was prepared by a solvent evaporation method. The optimal formulation was selected by orthogonal experimental design, and a reasonable evaluating method of the complexation rate was established. Various methods, such as differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and 31P nuclear magnetic resonance (31P-NMR), were used to explore the phase state and formation mechanism of the complex. The solubility of drug in complex was investigated in water/n-octanol. Preliminary study of its absorption and liver tissue distribution in rats was also carried out. The results showed that Bicyclol and phosphatidylcholine can be complexed entirely in the molar ratio 1 : 2. Bicyclol was dispersed in phospholipids as amorphous state. They were combined by intermolecular hydrogen bond due to charge transfer effect which occurred between the two polarities of the double bond between phosphorus and oxygen (P=O) of phosphatidylcholine and benzalcohol group of Bicyclol. The solubility of the complex compared to the active pharmaceutical ingredient (API) was effectively enhanced 5.75 times in water and 7.72 times in n-octanol, separately. In addition, drug concentrations were also enhanced 43 times in plasma and 13 times in liver with one hour after administering the complex to rats via oral gavage. All of these indicated that Bicyclol with benzalcohol group can interact with phospholipids to form complex, improving drug's physicochemical properties, thus further increasing its absorption and target tissue distribution. This study also provided theoretical reference for the research of other benzalcohol derivatives complexed with phospholipids.
1-Octanol ; Animals ; Biological Availability ; Biphenyl Compounds ; pharmacokinetics ; Calorimetry, Differential Scanning ; Chemistry, Pharmaceutical ; Phospholipids ; pharmacokinetics ; Rats ; Solubility ; Spectroscopy, Fourier Transform Infrared ; Tissue Distribution ; X-Ray Diffraction

AIMTo study the drug metabolizing enzymes involved in the metabolism of bicyclol and identify the major metabolites of bicyclol in rat and human liver microsomes.

METHODSBicyclol was incubated with rat and human liver microsomes. The metabolites of bicyclol were isolated by HPLC and identified by MS and 1H NMR.

RESULTSThe metabolic rate of bicyclol in DEX-induced rat liver microsomes was obviously higher than that in untreated microsomes, while it was much lower in human liver microsomes. Ketoconazole was capable to exhibit strong inhibition ( >90%) on bicyclol metabolism. Two metabolites of bicyclol were identified to be 4-hydroxy-4'-methoxy-6-hydroxy-methyl-6 '-methoxycarbonyl-2,3,2',3'-bis (methylene-dioxy) biphenyl and 4-methoxy-4'-hydroxy-6-hydroxymethyl-6'-methoxycarbonyl-2,3,2',3'-bis (methylene-dioxy) biphenyl.

CONCLUSIONCYP3A was considered as the major catalyst involved in bicyclol metabolism in vitro and two metabolites of bicyclol in rats were identified as 4-hydroxy-4'-methoxy-6-hydroxy-methyl-6 '-methoxycarbonyl-2,3,2',3'-bis (methylene-dioxy) biphenyl and 4-methoxy-4'-hydroxy-6-hydroxymethyl-6'-methoxycarbonyl-2,3,2',3'-bis (methylenedioxy) biphenyl.

Adult ; Animals ; Biphenyl Compounds ; metabolism ; pharmacokinetics ; Cytochrome P-450 Enzyme System ; metabolism ; Humans ; In Vitro Techniques ; Ketoconazole ; pharmacology ; Male ; Microsomes, Liver ; drug effects ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo investigate the effect of prescription compatibility on the pharmacokinetics of components from Dachengqi Decoction (DCQD, ) in rats.

METHODSTwenty-four male rats were randomly and equally divided into the DCQD group, Dahuang (Radix et Rhizoma Rhei, Polygonaceae) group, Houpo (Magnolia officinalis Rehd., Magnoliaceae) group, and Zhishi (Fructus Aurantii Immaturus, Rutaceae) group. The blood samples were collected before dosing and subsequently at 10, 15, 20, 30, 45 min, 1, 2, 4, 8, and 12 h following gavage. The levels of aloe-emodin, rhein, emodin, chrysophanol, honokiol, magnolol, hesperidin, and naringin in rat serum were quantified using a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for pharmacokinetic study.

RESULTSThe area under the curve (AUC), mean retention time (MRT), the peak concentration (C(max)) of aloe-emodin, rhein, emodin, and chrysophanol in the DCQD group were significantly different compared with the Dahuang group (P <0.05, respectively). The mean plasma concentration, C(max), and the absorption of Dahuang's component in the DCQD group were obviously lower at each time point than those in the Dahuang group, while the elimination process of Dahuang's component was obviously delayed (P <0.05). Half-lives of aloe-emodin, chrysophanol, and rhein were also extended in the DCQD group (P <0.05, respectively). In the DCQD group, the mean plasma concentration, AUC, C(max) and absorption of honokiol, and magnolol were significantly lower (P <0.01, respectively) at each time point than those in the Houpo group, while the drug distribution half-life time (T(1/2α)), the drug eliminated half-life time (T(1/2β)), MRT, and time of peak concentration (T(max)) were significantly delayed (P <0.05, respectively). Pharmacokinetic parameters of hesperidin and naringin in the Zhishi group were not significantly different as compared with the DCQD group (P >0.05, respectively), while the MRT of naringin was significantly longer.

CONCLUSIONSThe compatibility in Chinese medicine could affect the drug's pharmacokinetics in DCQD, which proves that the prescription compatibility principle of Chinese medicine formulations has its own pharmacokinetic basis.

Administration, Oral ; Animals ; Anthraquinones ; administration & dosage ; blood ; pharmacokinetics ; Biphenyl Compounds ; administration & dosage ; blood ; pharmacokinetics ; Drug Incompatibility ; Emodin ; administration & dosage ; blood ; pharmacokinetics ; Flavanones ; administration & dosage ; blood ; pharmacokinetics ; Hesperidin ; administration & dosage ; blood ; pharmacokinetics ; Lignans ; administration & dosage ; blood ; pharmacokinetics ; Male ; Plant Extracts ; administration & dosage ; blood ; chemistry ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley

Using sustained release tablets of gardenia extract as model drug and DPPH radical scavenging capacity as antioxidant index, the feasibility of using pharmacodynamics index was explored to evaluate sustained release tablets. Applying the established quantifiable method of DPPH radical scavenging to the dissolved liquid of model drug, release profiles and biological effects profiles were drawn, and their correlation was discussed. A good correlation was observed by linear regression and f2 actor, suggesting that the indicator could be used to evaluate sustained release tabletsofextracts of gardenia in which iridoids were mainly involved.
Antioxidants ; metabolism ; pharmacology ; Biphenyl Compounds ; metabolism ; Delayed-Action Preparations ; metabolism ; pharmacokinetics ; Free Radicals ; metabolism ; Gardenia ; chemistry ; Kinetics ; Linear Models ; Oxidation-Reduction ; drug effects ; Picrates ; metabolism ; Plant Extracts ; metabolism ; pharmacokinetics ; Tablets

The purpose of this study is to explore the feasibility and superiority of using rapid expansion of supercritical solution (RESS) technology in the field of traditional Chinese medicine. The extract of magnolia bark (EMB) was obtained by supercritical carbon dioxide (SCF-CO2) extraction technology. Microparticles of EMB were manufactured by RESS technology. The effects of operating temperature and pressure on the contents of the active ingredient in the particles were evaluated by HPLC. The effect of expansion conditions on the particle size distribution of EMB particles was investigated. The smallest sample (mean size: 4.7 microm) was obtained under the RESS condition: pressure of 25 MPa, temperature of 50 degrees C and a nozzle size of 100 microm. The characteristics of microparticles were also studied by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and image analysis. The dissolution rate study showed that microparticles had a significantly faster dissolution rate than normal material particles. After oral raw EMB suspension, the mean areas under the plasma concentration-time curves (AUC(0-t)) of honokiol and magnolol were found to be (4.23 +/- 0.36) and (5.46 +/- 0.57) mg x h x L(-1), respectively, which were increased significantly, i.e. (5.41 +/- 0.63) and (7.24 +/- 0.83) mg x h x L(-1) when micronized EMB suspension was administered orally in SD rats (P < 0.05). Similarly, the mean maximum plasma concentrations of honokiol and magnolol increased from (1.55 +/- 0.22) and (2.35 +/- 0.14) mg x L(-1) (raw EMB) to (2.31 +/- 0.17) and (2.84 +/- 0.21) mg x L(-1) (micronized EMB), respectively. The results of t-test demonstrated that AUC(0-t) and Cmax value for honokiol and magnolol was significantly increased with the micronization compared to raw EBM (P < 0.05). This study demonstrated that the RESS was applicable for preparing microparticles of EMB at low operating temperature. The process was simple, free of environment pollution and without residual solvent.
Administration, Oral ; Animals ; Area Under Curve ; Biphenyl Compounds ; blood ; pharmacokinetics ; Drug Compounding ; methods ; Drugs, Chinese Herbal ; administration & dosage ; chemistry ; isolation & purification ; pharmacokinetics ; Lignans ; blood ; pharmacokinetics ; Magnolia ; chemistry ; Male ; Microspheres ; Particle Size ; Plant Bark ; chemistry ; Plants, Medicinal ; chemistry ; Rats ; Rats, Sprague-Dawley ; Solubility