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A blood-brain barrier microfluidic chip platform for studying the permeability of active components in traditional Chinese medicine was developed. This model used primary human brain microvascular endothelial cells on a microfluidic chip consisting of two perpendicularly-crossing channels and a single layer porous polycarbonate membrane. The physiological shear stress in the human vasculature was also modeled in this device. Cell viability on the chip was monitored by cell staining and immunofluorescence staining. The cells spread well and the structure of an intercellular adhesion protein was satisfactory. The permeability of fluorescent tracers and three model drugs and the functional expression of P-glycoprotein (P-gp)on the blood-brain barrier were investigated. The results show that the apparent permeability coefficients (Papp) of the fluorescent tracers and three model drugs were consistent with those reported in the literature, and P-gp on the chip showed normal function, indicating that there was a complete structure and a functional BBB. The permeability of six active components of traditional Chinese medicine was investigated through this microfluidic chip and the drug concentration was determined by HPLC-MS/MS to obtain the Papp of each component. The Papp of corydaline was (4.51 ± 1.90)×10-7 cm·s-1, the Papp of tetrahydropalmatine was (9.10 ± 6.59)×10-7 cm·s-1, and the Papp of imperatorin was (9.38 ± 2.53)×10-7 cm·s-1; the concentration of isoimperatorin, baicalin and chlorogenic acid was below the limit of quantification, which suggested that isoimperatorin, baicalin and chlorogenic acid have poor permeability in this BBB chip. This blood-brain barrier microfluidic platform possesses a complete barrier function and near-physiological conditions and could be a valuable in vitro tool for drug permeability evaluation.
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OBJECTIVE: To study the transport of lipoamide (LAM) and lipoic acid (LA) in Caco-2 cell monolayer model in vitro. METHODS: Effects of LAM and LA on the survival rate of Caco-2 cells were investigated by MTS, the bi-directional transport of lipoamide and lipoic acid from the intestinal cavity side (apical side, AP) to the basal side (basolateral side,BL) was investigated. The cumulative transport volume, apparent permeability coefficient (Papp) and transport percentage were calculated,and the relationships between transport volume and concentration and time were further studied. RESULTS: The transport amounts of LAM and LA were increased in time-and concentration-dependent manners, the Papps of LAM and LA (AP→BL) were 2.443 44×10-5-2.392 91×10-5 and 8.179 78×10-6-7.897 25×10-6 cm•s-1, and the Papps(BL→AP) were 2.258 13×10-5-2.214 3×10-5 and 8.267 98×10-6-7.926 73×10-6 cm•s-1, respectively. CONCLUSION: In the transport test of Caco-2 cells, LAM is superior to LA, suggesting that it is well absorbed orally and has high bioavailability. But it is still necessary to verify the pharmacokinetic data in vivo.
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Objective: To study the relationship between the drug form of curcumin self-nano-emulsion (Cur-SNEDDS) after being dispersed in artificial gastrointestinal fluid and intestinal absorption in rats. Methods: The change trend of curcumin concentration-time curve was used to express the change of precipitation growth. The content and existing form of precipitation were studied by polarized light microscope (PLMC), HPLC, UV full-wavelength (UV) scanning, X-ray powder diffraction (XRD), differential scanning calorimeter (DSC), infrared spectrum (FT-IR), Raman spectrum and nuclear magnetic resonance hydrogen spectrum (1H-NMR). At the same time, the rat valgus intestinal sac model was used to investigate the effect of SNEDDS on the apparent permeability coefficient (Papp) of curcumin. Results: The content of curcumin in the precipitation produced by Cur-SNEDDS dispersion was about 95% of that of curcumin API, and the chemical structure did not change, but the crystal form changed, resulting in amorphous precipitation. Curcumin intermolecular interaction occurred in the dispersion system, and hydrogen bonds were formed. Compared with curcumin, Cur-SNEDDS significantly increased the release rate and degree of curcumin in vitro, and enhanced the absorption of curcumin in duodenum, jejunum, ileum and colon, and the Papp value increased by 6.22, 12.97, 25.71 and 36.75 times, respectively. Conclusion: After Cur-SNEDDS dispersion, the crystal structure of curcumin is changed, which exists in free, amorphous and crystal form, so as to significantly improve the in vitro release and intestinal absorption of curcumin.
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OBJECTIVE: To study the absorption characteristics of cajanonic acid A using in vitro Caco-2 cell model. METHODS: The toxicity of cajanonic acid A on Caco-2 cells was investigated by MTS, the bi-directional transport of cajanonic acid A from AP→BL and BL→AP was investigated, the cumulative transport and apparent permeability(Papp) were calculated,and the relationships between the transport amount and concentration, time, and the P-glycoprotein inhibitor verapamil were further studied. RESULTS: The transport amount of cajanonic acid A increased with time and concentration, the Papp from apical(AP) side to basolateral(BL) side was 2.01×10-6-3.95×10-6 cms-1, and the Papp from basolateral(BL) side to apical(AP) side was 2.51×10-6-6.03×10-6 cms-1. CONCLUSION: The current data suggests that the absorption of cajanonic acid A in the Caco-2 cell model is not a simple passive diffusion, the efflux ratio indicates that the efflux protein of P-gp may be involved, and the Papp suggests that the oral absorption is medium.
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Aim To prepare evodiamine butyryl deriva-tive (EBD) and evodiamine butyryl derivative-loaded solid lipid nanoparticles (EBDLN), and study its re-lease in vitro,and to investigate its in situ gastrointesti-nal absorption. Methods EBD was prepared by a one-step synthetized method, and then EBDLN was prepared by a film dispersion method. Dynamic dialy-sis was used to evaluate drug release in vitro,and sin-gle-pass gastrointestinal perfusion was employed to study the gastrointestinal absorption of EDM,EBD and EBDLN. Results In identical release media, there were identical drug release tendencies of EBD and EB-DLN, but the release rate of EBDLN was faster than EBD. Compared with EDM and EBD, the Kavalues and Pappvalues of EBDLN in every perfusion segment increased significantly. The Kaof EBDLN in stomach, duodenum, jejunum, ileum and colon was 110.14-fold,56.70-fold,51.23-fold,45.70-fold and 127.23-fold of free EDM respectively. The Pappvalue of EB-DLN was 9.74-fold, 4.48-fold, 3.82-fold and 11.3-fold of that of free EDM. Conclusion EBDLN has sustained effect and can enhance the gastrointestinal absorption of EDM and EBD.
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Tongmai formula (TMF) is a drug combination of three components including Puerariae Lobatae Radix [roots of Pueraria lobata], Salviae Miltiorrhizae Radix (roots of Salvia miltiorrhiza) and Chuanxiong Rhizoma (rhizomes of Ligusticum chuanxiong) in a weight ratio of 1∶1∶1. The absorption and transport of isoflavonoid compounds from Tongmai formula across human intestinal epithelial (Caco-2) cells in vitro were studied in this paper. The assay isoflavonoid compounds include daidzein, formononetin, 5-hydroxylononin, ononin, daidzin, 3'-methoxypuerarin, genistin, puerarin, formononetin-8-C-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranoside, formononetin-7-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranoside, lanceolarin, kakkanin, daidzein-7,4'-di-O-β-D-glucopyranoside, mirificin, 3'-hydroxypuerarin, 3'-methoxydaidzin, formononetin-8-C-β-D-xylopyranosyl-(1→6)-O-β-D-glucopyranoside, genistein-8-C-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranoside, genistein-7-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranoside (ambocin), 3'-hydroxymirificin, 6″-O-β-D-xylosylpuerarin, biochanin A-8-C-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranoside, 3'-methoxydaidzein-7,4'-di-O-β-D-glucopyranoside, daidzein-7-O-β-D-glucopyranosyl-(1→4)-O-β-D-glucopyranoside, and daidzein-7-O-α-D-glucopyranosyl-(1→4)-O-β-D-glucopyranoside. By using human Caco-2 monolayer as an intestinal epithelial cell model in vitro, the permeability of above-mentioned 25 isoflavonoids in TMF were studied from the apical (AP) side to basolateral (BL) side or from the BL side to AP side. The assay compounds were determined by reversed phased high-performance liquid chromatography (HPLC) coupled with UV detector. Transport parameters and apparent permeability coefficients (Papp) were then calculated and and compared with those of propranolol and atenolol, which are the transcellular transport marker and as a control substance for high and poor permeability, respectively. The Papp values of daidzein and formononetin were (2.55±0.03) ×10⁻⁵,(3.06±0.01) ×10⁻⁵ cm•s⁻¹ from AP side to BL side, respectively, and (2.62±0.00) ×10⁻⁵, (2.65±0.11) ×10⁻⁵ cm•s⁻¹ from BL side to AP side, respectively. Under the condition of this experiment, the Papp value was (2.66±0.32) ×10⁻⁵ cm•s⁻¹ for propranolol and (2.34±0.10) ×10⁻⁷ cm•s⁻¹ for atenolol. The Papp values of daidzein and formononetin were at a same magnitude with those of propranolol. And the Papp values of other 23 isoflavonoid compounds were at a same magnitude with those of atenolol. On the other hand, the rats of Papp AP→BL/Papp BL→AP of daidzein and formononetin on the influx transport were 0.97 and 1.15, respectively. It can be predicted that daidzein and formononetin can be absorbed across intestinal epithelial cells to go to the body circulation by the passive diffusion mechanism and they were assigned to the well-absorbed compounds. Other 23 isoflavonoid compounds were assigned to the poorly absorbed compounds. Because of the rats of Papp AP→BL/Papp BL→AP of 5-hydroxylononin, genistin, lanceolarin, kakkanin, and genistein-7-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranoside were 0.18, 0.28, 0.45, 0.38, 0.49, they may have been involved in the efflux mechanism in Caco-2 cells monolayer model from the BL side to AP side direction.
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Objective: To study the effects of β-cyclodextrin (β-CD), hydroxypropyl-β-CD (HP-β-CD), and sulfobutyl-ether-β-CD (SBE-β-CD) on in vitro corneal penetration of curcumin. Methods: Improved Franz-cells were used for the corneal diffusion test and the cumulative permeation quantity of curcumin in the corneal was determined by HPLC. Results: β-CD at 0.02%, 0.04%, 0.06%, and 0.08% improved the apparent permeability coefficient as much as 1.06, 1.03, 1.00, and 0.95 times. HP-β-CD at 0.02%, 0.04%, 0.06%, and 0.08% improved the apparent permeability coefficient as much as 1.16, 1.19, 1.17, and 1.12 times; HP-β-CD at 0.04% and 0.06% there was a significant deference compared with the control group (P < 0.05). SBE-β-CD at 0.02%, 0.04%, 0.06%, and 0.08% improved apparently the permeability coefficient as much as 1.06, 1.23, 1.08, and 0.90 times. SBE-β-CD at 0.04% there was a significant deference compared with the control group (P < 0.05). SBE-β-CD at 0.06% as penetration enhancer, release curve accorded with zero order release equation (r = 0.9978). The average of the corneal hydration is 81.7%. Conclusion: HP-β-CD at 0.04% and 0.06% could improve the apparent permeability coefficient as much as 1.19 and 1.17 times (P < 0.05). SBE-β-CD at 0.04% could improve the apparent permeability coefficient as much as 1.23 times (P < 0.05). SBE-β-CD as corneal penetration enhancers can release safely and effectively. As corneal penetration enhancers, those three kinds of cyclodextrin are without irritation to corneal.
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Objective: To research the correlation between compositions and absorption of the multi-components in Coptidis Rhizoma and to explore the methods suitable for identifying the interactions of multi-components in Coptidis Rhizoma during the absorption process. Methods: Samples of various compositions by their different combinations of each component in Coptidis Rhizoma were designed and prepared using Caco-2 monolayer model. Using HPLC method for the simultaneous quantitative determination, taking the inherent apparent permeability coefficients (Papp) by the individual transport of each component as reference, the least square multi-linear regression was used for data fitting to obtain the correlation between interaction intensity of Papp and concentration of each component by their different combinations and to analyze the interaction type and intensity of multi-components during the absorption. Results: The quantitative relationship of multi-component interactions for coptisine, jatrorrhizine, berberine, and palmatine was obtained, respectively. The main contributors for the multi-component interaction, including single component and interactive products of the different components, were also identified. The quantitative relationship affecting the absorption was also obtained. Conclusion: A well-designed method for studying the multi-component interactions of Coptidis Rhizoma using mathematical method is practicable.
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OBJECTIVE: To study the transdermal absorption mechanism and Methods of absorption promotion of bergenin so as to optimize its safe, stable and effective osmotic pump preparation. METHODS: Caco-2 cell monolayer model was used to measure the apparent permeability coefficients(Papp) and transport rate of all samples considering the major relevant factors of osmotic pump preparation design of insoluble drugs. RESULTS: Pappvaried little while concentration of bergenin increased. The efflux rate(ER) was smaller than 1.5. Angelica dahurica extract, agnuside, Artemisia argyi oil, platycodin, oleanolic acid and ursolic acid had significant effects on the Papp and transport rate of bergenin. The inclusion compound and solid dispersion techniques could enhance the absorption of bergenin. The two common hydrophilic polymer excipients of osmotic pump preparation could not improve the membrane absorption rate and permeability of bergenin. CONCLUSION: The absorption of bergenin across Caco-2 cell monolayer model may be passive transport. The study reveals possible directions for design of bergenin osmotic pump preparation.
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duodenum, respectively. Conclusion The absorption of tetrandrine is first-order process with passive diffusion mechanism. Tetrandrine is well absorbed at all segments of intestine in rats.