The intestinal absorption characteristics of five active components in Lizhong Decoction / 药学学报

The intestinal absorption properties of the main effective components (glycyrrhizic acid, isoliquiritigenin, 6-gingerol, ginsenoside Rb1, atractylode-I) in Lizhong decoction (LZD) extracts were investigated with an in situ single-pass intestinal perfusion model in rats. UPLC-TQ-MS was used to determine the concentration of the five components in the intestinal perfusion. Animal welfare and experimental procedures were in accordance with the regulations of the Animal Ethics Committee of Nanjing University of Chinese Medicine. As evaluation indexes for the intestinal absorption characteristics, the absorption rate constant (Ka) and the apparent permeability coefficient (Peff) of the five main ingredients were analyzed. Results showed that the best absorption sites for glycyrrhizic acid, isoliquiritin and 6-gingerol were the ileum, colon and duodenum, respectively, and the differences between different intestinal segments were statistically significant (P <0.05). There was no notable difference in Ka and Peff between ginsenoside Rb1 and atractylode-I in the different intestinal segments (P > 0.05), suggesting that they were absorbed throughout. The five components were well-absorbed in the whole intestine (Peff > 1.0×10-3 cm·min-1), indicating that LZD is suitable for preparing sustained, controlled release and enteric-coated preparations.

Effect of paracellular permeation enhancers on intestinal permeability of two peptide drugs, enalaprilat and hexarelin, in rats

Transcellular permeation enhancers are known to increase the intestinal permeability of enalaprilat, a 349 Da peptide, but not hexarelin (887 Da). The primary aim of this paper was to investigate if paracellular permeability enhancers affected the intestinal permeation of the two peptides. This was investigated using the rat single-pass intestinal perfusion model with concomitant blood sampling. These luminal compositions included two paracellular permeation enhancers, chitosan (5 mg/mL) and ethylenediaminetetraacetate (EDTA, 1 and 5 mg/mL), as well as low luminal tonicity (100 mOsm) with or without lidocaine. Effects were evaluated by the change in lumen-to-blood permeability of hexarelin and enalaprilat, and the blood-to-lumen clearance of

Preparation of glycyrrhizic acid-F127/TPGS mixed nanomicelles and its in vivo intestinal absorption in rats / 中草药

Objective: To prepare glycyrrhizic acid (GL)-Pluronic F127 (F127)/polyethylene glycol 1000 vitamin E succinate (TPGS) mixed nanomicelles (MMs) and improve oral absorption of GL. Methods: GL-F127/TPGS-MMs was prepared by thin film dispersion method. The encapsulation efficiency and drug loading of MMs were used as evaluation indexes. The formulation and process, including the ratio of F127 to TPGS, the concentration of polymer and GL, hydration temperature and time, were optimized by the single factor experiment. The morphology of MMs was investigated by transmission electron microscopy. The single-pass perfusion model was established in rats to investigate the intestinal absorption characteristics of GL-F127/TPGS-MMs with absorption rate constant (Ka) and apparent absorption coefficient (Papp) as evaluation indexes. Results: The optimal formulation and process of GL-F127/TPGS-MMs were as follows: TPGS 180 mg, F127 270 mg, GL 70 mg, hydration temperature 50 ℃ and hydration time 3 h. The prepared GL-F127/TPGS-MMs had good clarity and the particle size, polydispersity index, and Zeta potential were (28.20 ± 5.63) nm, 0.20 ± 0.06, and (-5.24 ± 1.55) mV, respectively. The encapsulation efficiency and drug loading were (97.57 ± 5.29) % and (13.13 ± 0.71) %, respectively. The MMs were spherical with distinct vesicle structure. The absorption of GL in the jejunum segment was significantly higher than that in the ileum segment (P < 0.05). Compared with raw GL, GL-F127/TPGS-MMs had a statistically significant higher absorption rate in the intestinal segment (P < 0.05). Conclusion: The prepared GL-F127/TPGS-MMs could significantly improve the absorption of GL in vivo.

Pharmacokinetics and in situ intestinal absorption of evodiamine lipidic nanoparticle / 中国药科大学学报

@#The aim of this study was to investigate the in vivo pharmacokinetic behavior characteristics and in situ intestinal absorption characteristics of the evodiamine lipidic nanoparticle in rats. Evodiamine lipidic nanoparticle was prepared by the solvent evaporation methods. The particle size and zeta potential of evodiamine lipidic nanoparticle were measured by dynamic light scattering analysis. Male SD rats were divided into two groups randomly. Each group was given single dose of evodiamine and evodiamine lipidic nanoparticle by gavage at evodiamine dose of 250 mg/kg,respectively. The blood samples were collected at scheduled time points. The content of evodiamine in plasma samples was determined by high performance liquid chromatography (HPLC) method. The main pharmacokinetic parameters of evodiamine and evodiamine lipidic nanoparticle were calculated using DAS 2.1.1 software. Moreover,the single-pass intestinal perfusion model was also established in rats to investigate the in situ intestinal absorption characteristics of evodiamine lipidic nanoparticle. The mean particle size and mean zeta potential of evodiamine lipidic nanoparticle were 180.10 nm and -17.90 mV,respectively. The area under the curve of evodiamine and evodiamine lipidic nanoparticle were (862.60±14.03) and (4084.31±17.21) μg/L·h,respectively,and the peak concentration were (163.40±13.27) and (616.90±21.04) μg/L,respectively. Moreover,the absorption of evodiamine lipidic nanoparticle was significantly higher than that of evodiamine in each segment of intestinal tract in rats (P<0.05). The absorption of evodiamine lipidic nanoparticle in colon was better than those of evodiamine lipidic nanoparticle in stomach,duodenum,jejunum and ileum. The absorption rate constant of evodiamine lipidic nanoparticle in stomach,duodenum,jejunum,ileum and colon were (45.10±6.08)×10-5,(48.20±1.21)×10-5,(22.10±3.18)×10-5,(59.10±1.21)×10-5 and (90.00±3.85)×10-5 s-1,respectively,and the effective permeability coefficient in duodenum,jejunum,ileum and colon was (44.10±0.51)×10-5,(17.21±0.77)×10-5,(35.36±0.31)×10-5 and (40.33±0.34)×10-5 cm/s,respectively.All in all, evodiamine lipidic nanoparticle remarkably improved the in situ intestinal absorption of evodiamine in different segments of the intestinal tract in rats and its oral bioavailability in rats.

Study on Intestinal Absorption Characteristic Differences of 6 Active Constituents of Polygonum orientale in Normal and Myocardial Ischemia Model Rats / 中国药房

OBJECTIVE：To s tudy the intestinal absorption differences of 6 kinds of active constituents of Polygonum orientale （kaempferol，isokaempferol，vitexin，protocatechuic acid ，kaempferol-3-O-β-D-glucoside and quercetin ）in normal and myocardial ischemia（MI）model rats. METHODS ：UPLC-MS/MS method was adopted to determine the contents of 6 active components in the intestinal circulatory perfusion fluid. Totally male SD 80 rats were divided into normal group and model group ，with 40 rats in each group. Model group was given isoproterenol hydrochloride （50 mg/kg） subcutaneously to induce MI model；normal group was given constant volume of normalsaline， once a day ， for consecutive 2 days. 24 h after successful molding ，normal group and model group received in-situ intestinal circulatory perfusion experiment. The effects of different concentration s of P. orientale extract（5.0，10.0， 20.0 mg/mL），different intestinal segments （duodenum，jejunum，ileum，colon），P-glycoprotein（P-gp）inhibitors（verapamil） and bile on the intestinal absorption of each constituent were explored. RESULTS ：The linear ranges of concentrations of kaempferol， isokaempferol， vitexin， protocatechuic acid ， kaempferol-3-O-β-D-glucoside and quercetin were 3.15-50.40， 3.21-51.31，1.63-52.43，1.60-50.94，1.31-20.97，8.07-129.25 µg/mL（r＞0.999）. The lower limits of quantification were 7.86， 8.45，6.52，4.00，3.28，16.14 ng/mL，respectively. RSDs of precision ，matrix effect and stability tests were all lower than 11％； the accuracy were 85.64％-107.65％，which were in line with the requirements of biological sample quantification analysis. Except for there was no statistical significance in the absorption of kaempferol absorption in duodenum of model group at different concentrations，absorption of other five constituents in duodenum of normal and model rats increased with the increase of the concentration of active constituents ，and absorption of medium- and/or high- concentration active constituents （except quercetin ）in model group was significantly lower than normal group （P＜0.05）. In normal group ，the absorption of kaempferol was more in jejunum，ileum and colon ，isokaempferol was more in ileum ，vitexin and protocatechuic acid were more in jejunum and ileum ， kaempferin-3-O- β-D-glucoside was more in duodenum ，jejunum and colon ，quercetin was more in colon ；in the model group ，the absorption of Polygonum orientale in jejunum and colon was more ，the absorption of isokaempferol in 4 intestinal segments was little different ，vitexin was mainly absorbed in ileum ，protocatechuic acid and kaempferol- 3-O-β-D-glucoside was mainly absorbed in jejunum ，quercetin was mainly absorbed in duodenum and ileum ；in the same intestine ，the absorption of constituents in the model group was less than normal group. After adding verapamil ，absorption of all constituents in the normal group increased ，but the difference was not statistically significant （P＞0.05）；absorption of kaempferol ，isokaempferol，vitexin，protocatechuic acid and kaempferol- 3-O-β-D-glucoside were all increased significantly in model group （P＜0.05），while there was no statistical significance in the increase of quercetin （P＞0.05）. After the bile flowed into the duodenum ，absorption of protocatechuic acid was increased significantly in normal group （P＜0.05）；absorption of other active constituents were increased significantly in model group，except for isokaempferol and quercetin （P＜0.05）. CONCLUSIONS ：Six active constituents of P. orientale were absorbed in the whole intestine of normal and MI model rats ，and the absorption of above constituents may be enhanced more significantly by P-gp inhibitor and bile under pathological condition.

Intestinal absorption features of Tripterygium wilfordii solid dispersion in rats with single-pass intestinal perfusion model / 中草药

Objective To study the intestinal absorption kinetics of Tripterygium wilfordii (TW) solid dispersions and the effects of different intestinal segments, drug concentrations, pH value, and P-glycoprotein (P-gp) on intestinal absorption. Methods The absorption behavior was investigated in situ with a single-pass intestinal perfusion (SPIP) model in rats. The content of each index component was determined by HPLC. The gravimetric method was used to correct the data and calculate the absorption rate constant (Ka) and apparent permeability coefficient (Papp) of each index component. Results The index components of TW were absorbed in the whole intestine, and the absorption rate constant (Ka) of all the index components of TW solid dispersion was significantly increased than that of extract (P < 0.05), and had some differences among different segments. With the increase of drug concentration, the absorption of each index component had saturation phenomenon, which indicated that it may be carrier-mediated transport mechanism. Acidic environment (pH 5.4) was beneficial to the absorption of various index components, especially the acidic content celastrol. After adding P-gp inhibitor, the Ka and Papp of celastrol were significantly different from those without P-gp inhibitor (P < 0.05), which suggested that it may be the P-gp substrate. Conclusion All the index components of TW solid dispersion are absorbed in the whole intestine and have saturation phenomenon, which suggested the absorption may be carrier-mediated transport mechanism. Acidic environment is beneficial to the absorption of all components. The absorption process of celastrol is affected by drug concentration and P-gp inhibitor, which indicated that it may be P-gp substrate. The preparation of solid dispersing can significantly enhance the absorption of various components of TW, suggesting that all the index components are BCS II drugs, and the bioavailability of the preparation may be improved.

Applicability analysis and evaluation of aglycones in single-pass intestinal perfusion technique based on PBPK model / 中国中药杂志

Single-pass intestinal perfusion( SPIP) is the common carrier of biopharmaceutics classification system( BCS) to study compound permeability. With the application and deepening study of BCS in the field of traditional Chinese medicine( TCM),SPIP model is becoming more and more common to study the intestinal absorption of TCM ingredients. Based on the limitations of the SPIP model in some researches on TCM permeability,it was speculated in this study that aglycone may be more suitable than the glycoside to study the intestinal absorption problem by using SPIP model. Furthermore,applicability of aglycone components was analyzed and evaluated. In this study,with quercetin,daidzein,formononetin,genistein and glycyrrhetinic acid used as research objects,the quantitative study of SPIP was used to evaluate the intestinal permeability of these aglycones and to predict the effective permeability coefficient( Peff) and absorption fraction( Fa) in human body. By combining studies comparison and analysis on multiple permeability research methods and prediction of human body absorption of aglycones in physiological-based pharmacokinetic models,this paper can further illustrate that the SPIP model is a good tool for studying the permeability of aglycones and predicting human absorption,which can provide data foundation and theoretical reference for researches on SPIP technique and BCS in intestinal absorption of TCM ingredients.

Research on attributes of biopharmaceutics classification system for Chinese materia medica of baicalein in Gegen Qinlian Decoction environment / 中国中药杂志

For the effects of multi-component environment on the solubility and permeability of single components,and the problems of biopharmaceutical attribute classification of single components in the compound prescriptions environment,baicalein was used as the research object in this study to investigate the biopharmaceutic attributes of single-component and their traditional Chinese medicine( TCM) biopharmaceutic attributes in the multi-component environment of Gegen Qilian Decoction. Shaking flask method,intrinsic dissolution rate test and HPLC were used to determine solubility of baicalein. Markers specified by FDA were utilized as permeable boundary reference materials to verify the applicability of the single-pass intestinal perfusion method( SPIP),and the quantitative research on the permeability of baicalein was also conducted. It is concluded that baicalein could be categorized as BCS-Ⅱ drug based on its low solubility and high intestinal permeability values,and it may be categorized into CMMBCS-I in the multi-component environment of Gegen Qilian Decoction due to its poor solubility but enhanced solubility and permeability in compound environment. This study could provide verification ideas for clinical determination of the best human oral dose of baicalein,and provide the data basis for the study of biopharmaceutics classification system of Chinese materia medica( CMMBCS).

Study on compatibility of active ingredients of Simiao Yongan Decoction in rats with in situ single-pass intestinal perfusion model / 中国中药杂志

To study the compatibility rule of Simao Yongan Decoction,the rat single pass intestinal perfusion model in situ was used in this study. On the basis of early research,the five kinds of anti-inflammatory active ingredients,i.e. chlorogenic acid,liquiritin,hyperoside,angoroside C and isochlorogenic acid C in Simao Yongan Decoction were selected as research objects. The contents of the above five actives compounds with various compatibility combinations and in different intestinal segment perfusates were determined by using the method of ultra-performance liquid chromatography-mass spectrometry( UPLC-MSn). The kinetic parameters of intestinal absorption of the five anti-inflammatory active ingredients were calculated,which could be used to evaluate the intestinal absorption of each component in different combinations. The results showed that the absorption parameters of liquiritin in ileum were highest in Glycyrrhizae Radix et Rhizoma single herb,while the absorption parameters of other four components in ileum and duodenum were highest in the compatible combinations. Among them,the absorption parameters of chlorogenic acid in ileum and duodenum were highest in the whole prescription compatibility; ischlorogenic acid C showed higher absorption levels in the whole prescription and the herb compatibility of Lonicerae Japonicae Flos-Scrophulariae Radix-Glycyrrhizae Radix et Rhizoma. However,the absorption levels of hyperoside and angoroside C in different compatibilities were quite different in ileum and duodenum. In this study,the intestinal absorption of five anti-inflammatory active ingredients in Simiao Yongan Decoction with different compatibility combinations was investigated,revealing that the absorption of active ingredients varied with the different compatibility combinations and different intestinal segments. At the same time,the above research also indicated that the absorption of active ingredients could be obviously promoted by the compatibility of compound prescriptions,laying a foundation for the research on the compatibility rule of Simiao Yongan Detection from the biological point of view.

Intestinal absorption of phenolic acids in Rhus chinensis extracts by in situ single-pass perfusion model in rats / 中国中药杂志

The intestinal absorption properties of four main effective components(gallic acid, ocinolglucoside, ethyl gallate and penta-O-galloyl-β-D-glucose) in Rhus chinensis extracts were investigated by in situ single-pass intestinal perfusion model in rats. The liquid accumulation of perfusion was corrected by gravimetry. The HPLC method was established to determine the concentration of the four effective components in the intestinal perfusion. It showed significant differences(Pethyl gallate>gallic acid>ocinolglucoside, with significant differences between them(P<0.05). In conclusion, gallic acid, orpheolglucoside, ethyl gallate and pentacyl-glucose could be absorbed in the whole intestine. Their absorption rate and permeation ability were related to the intestinal section and the perfusate concentration. These results indicated potential active transport or facilitated diffusion in the intestinal transport process of the four effective components.

Effect of processing excipient suet oil on formation and absorption of baohuoside Ⅰ-bile salt self-assembled micelles / 中国中药杂志

The fried method with suet oil,which can strengthen the effect of Epimedium in warming kidney and enhancing Yang,has been widely used in the processing of Epimedium in traditional Chinese medicine. Based on the formation mechanism of Epimedium flavonoids self-assembled micelles in vivo,the synergistic mechanism of processing excipient suet oil was investigated in this paper from the perspective of pharmaceutics. Baohuoside Ⅰ,as representative component of processed Epimedium,was selected as model drug.Average size and zeta potential were measured and the morphology of micelles was observed under transmission electron microscopy. Caco-2 monolayer cell model,rat intestinal perfusion model and in vivo serum drug concentration method were established to investigate the effect of suet oil on the formation and absorption of the baohuosideⅠ bile salt self-assembled micelles. Baohuoside Ⅰ can form selfassembled micelles under the action of sodium deoxycholate. While,adding suet oil into the baohuoside Ⅰ-bile salt micelles( BSDOC) can make it form a more stable system with a smaller average size,higher Zeta potential,lower polydispersity index( PDI) value,significantly improved encapsulation efficiency and drug loading,indicating that suet oil could significantly improve the micelle formation in vivo. In addition,the permeability coefficient of baohuoside Ⅰ in Caco-2 monolayer cells and the four intestinal organs( duodenum,jejunum,ileum and colon) was increased and the oral bioavailability was also improved after adding the suet oil to BS-DOC.All the results demonstrated that the suet oil can promote the formation and absorption of baohuoside Ⅰ self-assembled micelles,so as to enhance its synergistic effects.

Effect of Acori Tatarinowii Rhizoma on Intestinal Absorption of Ginsenosides in Dingzhi Xiaowan / 中国实验方剂学杂志

Objective: To explore the effect of Acori Tatarinowii Rhizoma on intestinal absorption of ginsenosides in Dingzhi Xiaowan,and reveal the mechanism of Acori Tatarinowii Rhizoma acting as " adjuvant drug" in this formula. Method: The contents of ginsenoside Rg1,Re and Rb1 were measured by UPLC-MS/MS and the absorption of three ginsenosides in different intestine segments was investigated by rat single pass intestinal perfusion in situ,including absorption rate constant(Ka) and apparent permeability coefficient(Papp).Everted intestinal sac model was used to investigate the absorption dosage of three ginsenosides affected by volatile oil from Acori Tatarinowii Rhizoma and verapamil[Ver,a P-glycoprotein(P-gp) inhibitor]. Result:Papp values of three ginsenosides were ≤ 0.191×10-3 cm·min-1 in Dingzhi Xiaowan when lack of Acori Tatarinowii Rhizoma.Compared with lack of Acori Tatarinowii Rhizoma in Dingzhi Xiaowan group,the Ka and Papp values of lack of volatile oil from Acori Tatarinowii Rhizoma in Dingzhi Xiaowan group slightly increased without significant difference in the four intestinal segments,but when the prescription had Acori Tatarinowii Rhizoma,the Ka increased by 3.97-8.35 fold and the Papp increased by 3.99-8.49 fold.The results of everted intestinal sac test showed that volatile oil of Acori Tatarinowii Rhizoma could significantly promote the intestinal absorption of ginsenoside Rg1,Re and Rb1,but there was no dose-dependent. Conclusion:Volatile oil of Acori Tatarinowii Rhizoma can promote the intestinal absorption of three ginsenosides in Dingzhi Xiaowan,and the mechanism may be related to the inhibiting function on P-gp.

Advances in models for predicting drug intestinal permeability / 药学学报

Intestinal permeability is one of key factors determing absorption of oral drug products. It is a big challenge to assess permeability of compounds with high accuracy and high efficacy during research and development process. In this review, the principles, strengths, weaknesses and advances of common intestinal permeability models are summarized, with focus on Ussing chamber and parallel artificial membrane permeability assay. In addition, future trends of permeability models are briefly discussed. This review may provide a reference to accessing permeability of lead compounds.

Intestinal absorption of puerarin nanocrystalline self-stabilizing pickering emulsion in rats / 中国中药杂志

To study the intestinal absorption characteristics of drug's nanocrystalline self-stabilizing Pickering emulsion (NSSPE) in situ in rats. Rat single-pass intestinal perfusion model was established, and high performance liquid chromatography (HPLC) was used to detect the concentration of puerarin in rat intestinal perfusion solution, assay the absorption rate constant (Ka) and the intestinal apparent permeability coefficient (Papp) of NSSPE in duodenum, jejunum, ileum, and colon, which were compared with those of raw material, nanocrystal and normal emulsion, respectively. For NSSPE, the Ka and Papp values were in the following order: duodenum>jejunum>ileum (<0.05)>colon (<0.01). However, there was no obvious difference between jejunum and ileum. As compared with raw material, nanocrystal and normal emulsion, the Ka and Papp values of NSSPE in duodenum were significantly higher than those of other three preparations (<0.05); and the Ka and Papp values of NSSPE in jejunum and colon were significantly higher than those of raw material, nanocrystal and normal emulsion (<0.01); and the Ka and Papp of NSSPE in ileum were also higher than those of raw material and normal emulsion (<0.05), but had no obvious difference with nanocrystal. The results showed that NSSPE could significantly improve the absorption of puerarin in the intestine of rats.

In vitro release behavior and in situ absorption of evodiamine loaded microemulsion / 中国药理学通报

Aim To study the characteristics of in vitro release and in situ absorption of evodiamine load-ed microemulsion (EDM).Methods EDM was pre-pared, its release in pH 1.2 HCl solution and pH 6.8 phosphate buffer solution were studied by dialysis , and the cumulative release rates were calculated .The sin-gle-pass intestinal perfusion was used to study the ab-sorption of EDM in duodenum , jejunum , ileum and co-lon, the absorption in stomach was also studied , and the absorption rate constant ( Ka ) and effective perme-ability (Pef ) of the drug were calculated.The concen-tration of ED was measured by HPLC .Results The cumulative release rate of EDM and ED in pH 1.2 HCl solution was ( 64.76 ±0.73 )％, ( 13.98 ±0.49 )％, respectively , and that of EDM was 4.63 times of ED . In pH 6.8 phosphate buffer solution the cumulative re-lease rate was ( 91.72 ± 0.51 )％, ( 18.34 ± 0.20)％, respectively, which was 5.01 times of ED. The Ka of EDM was more than 3 times of ED, and Pef was more than 2 times of ED .Conclusion Microe-mulsion can improve in vitro release and in situ absorp-tion of ED.

Study on the Absorption Characteristics of Naringin in situ Single-pass Intestinal Perfusion Model of Rats / 中国药房

OBJECTIVE:To study absorption characteristics of naringin in situ single-pass intestinal perfusion model of rats. METHODS:UPLC method was established for the content determination of naringin and naringenin in intestinal perfusion samples of rats. The in situ single-pass intestinal perfusion model of rats was adopted to investigate intestinal(duodenum,jejunum,ileum and colon)absorption and metabolic characteristics [apparent permeability coefficient(Peff),absorptivity,metabolic rate] of naringin(10 μ mol/L). RESULTS:The linear range of naringin and naringenin were 1.25-40,1.25-40 μ mol/L(R2=0.999 4, 0.996 6). The detection limit were 0.5,0.4 μ mol/L,and limit of quantitation were all 1.25 μ mol/L. Precision of inter-day and intra-day,recovery and stability in HBSS solution,perfusion fluid of small intestine and colon were all in line with the standard. Peffof naringin in duodenum,jejunum,ileum and colon of rats were(0.28 ± 0.19),(0.71 ± 0.17),(0.30 ± 0.02),(0.59 ± 0.19) (n=6),without statistical significance(P>0.05).Absorptivities were(2.90±2.14)%,(6.38±3.61)%,(3.69±0.56)%,(6.64± 2.12)%(n=6). Naringin could be metabolized to naringenin in 4 intestinal segments of rats,with metabolic rate of(2.98 ± 1.51)%,(2.53 ± 1.31)%,(2.24 ± 1.33)%,(0.70 ± 0.20)%(n=6). The lowest absorptivity and the highest metabolic rate of naringin were occurred in the duodenum,there were statistical significance compared with colon(P<0.05). CONCLUSIONS:Naringin shows poor permeability and poor absorption in the intestinal tract of rats.There was no specific absorption site in the rat' s intestines for naringenin;naringin could be metabolized to naringenin in small intestine and colon,but metabolic rate of naringin in small intestine is higher than in colon.

Difference in intestinal absorption of Wuzhuyu decoction between normal and migraine model rats / 中国中药杂志

To compare the intestinal absorption of Wuzhuyu decoction(WZYD) between normal rats and migraine model rats, and investigate the optimized WZYD from aspect of absorption. The rat single pass intestinal perfusion test(SPIP) was adopted for optimized sample and un-optimized sample in normal and migraine model rats induced by nitroglycerin and reserpine. The contents of 8 ingredients were determined by high performance liquid chromatography(HPLC), and 4 absorption parameters for each ingredient were calculated and compared: unit area absorption(Mper area), absorption rate constant(Ka), apparent coefficient(Papp) and relative absorption rate(RA). The results showed that there was a great difference between normal rats and model rats in the intestinal absorption of the same WZYD. As compared with normal rats, the absorption parameters of most ingredients in optimized sample were increased in migraine model rats induced by nitroglycerin; Similar phenomena were also found in migraine model rats induced by reserpine. However, the absorption parameters of most ingredients were decreased in un-optimized sample. Therefore, pathological model rats shall be used for effective ingredient recognition based on the correlation between intestinal absorption spectra and pharmacological effects. As compared with the un-optimized samples, the absorption of effective ingredients was faster, easier and more adequate in the optimized samples, revealing their mechanism on better efficacy from the aspect of absorption.

Overall intestinal permeability of multiple components in lotus leaf by in situ single pass intestinal perfusion models / 中国中药杂志

To investigate the overall intestinal permeability of multiple components in lotus leaves and make clear the interaction in composition absorption process. Rat single-pass intestinal perfusion technique was used, and the results showed that the Peff values of nuciferine, demethylanuciferine, rutin, quercetin, kaempferol from lotus leaf were greater than 0.5×10⁻⁴ cm•s⁻¹. In the biopharmaceutics classification system (BCS) intestinal permeability property, these ingredients were high permeable components, while the hyperin was low permeable component. However, in the multi-component environment of the lotus leaf extract, component permeation was changed. Semi quantitative analysis of the unclear components showed that under the multi-component environment, four in seven components with relatively high contents had a Peff value less than 0.5×10⁻⁴ cm•s⁻¹, indicating these 4 components were of low permeability, while other 3 components were of high permeability. The results could be valuable to make clear the overall intestinal permeability of multiple components in lotus leaf, and lay a foundation for studying the mechanism of the lipid-lowering effect of lotus leaf.

Validation of in situ single pass perfusion model based on P-gp / 中国中药杂志

To validate in situ rats intestinal single pass perfusion model based on P-glycoprotein (P-gp). Firstly, phenol red perfusion was carried out to verify the close connection structure of intestinal epithelial cells, and the integrity of the intestinal epithelium, with a gravimetric method for correcting water flux. The level of phenol red was determined by high performance liquid chromatography (HPLC) both before and after perfusion. Secondly, the positive drug digoxin specified by FDA was used to validate the model. After different mass concentrations of verapamil were given in the rats, the absorption parameters of digoxin in ileum of rats were observed and compared. The results showed that the phenol red was absorbed in rats ileum segment, with an effective permeability coefficient of (1.09±0.62)×10 ⁻⁶ cm•s ⁻¹. The experiment results indicated that the close connection structure of intestinal epithelial cells was normal, and the integrity of the intestinal epithelium was maintained well. In digoxin perfusion experiment, in case no verapamil was given, digoxin showed certain degree of absorption in rat ileum, with an effective permeability coefficient (Peff) of (1.07±0.59)×10 ⁻⁵ cm•s ⁻¹; after mass concentrations of 0.01,0.1 mmol•L ⁻¹ verapamil were given, the absorption of digoxin was on the rise in rat ileum, with an effective permeability coefficient Peff of (1.58±0.69)×10 ⁻⁵, (3.28±0.95)×10 ⁻⁵ cm•s ⁻¹ respectively (P<0.05). Digoxin perfusion experiment verified that P-gp expression in small intestine epithelium was intact and can be used in the research of P-gp efflux transporter.

Self-microemulsifying drug delivery system for improving the bioavailability of huperzine A by lymphatic uptake

Huperzine A (Hup-A) is a poorly water-soluble drug with low oral bioavailability. A self-microemulsifying drug delivery system (SMEDDS) was used to enhance the oral bioavailability and lymphatic uptake and transport of Hup-A. A single-pass intestinal perfusion (SPIP) technique and a chylomicron flow-blocking approach were used to study its intestinal absorption, mesenteric lymph node distribution and intestinal lymphatic uptake. The value of the area under the plasma concentration-time curve (AUC) of Hup-A SMEDDS was significantly higher than that of a Hup-A suspension (<0.01). The absorption rate constant () and the apparent permeability coefficient () for Hup-A in different parts of the intestine suggested a passive transport mechanism, and the values ofandof Hup-A SMEDDS in the ileum were much higher than those in other intestinal segments. The determination of Hup-A concentration in mesenteric lymph nodes can be used to explain the intestinal lymphatic absorption of Hup-A SMEDDS. For Hup-A SMEDDS, the values of AUC and maximum plasma concentration () of the blocking model were significantly lower than those of the control model (<0.05). The proportion of lymphatic transport of Hup-A SMEDDS and Hup-A suspension were about 40% and 5%, respectively, suggesting that SMEDDS can significantly improve the intestinal lymphatic uptake and transport of Hup-A.