Intestinal Perfusion Studies Research Articles

Comparative pharmacokinetics of major bioactive components from Puerariae Radix-Gastrodiae Rhizome extracts and their intestinal absorption in rats

Puerariae Radix (PR) and Gastrodiae Rhizome (GR) is frequently used in traditional herbal formulas to treat cardio-cerebral vascular diseases due to their synergistic effects. In this study, to elucidate the action mechanism of PR-GR in vivo, a simple and reliable ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for simultaneous determination of nine bioactive ingredients from PR-GR in plasma was developed and applied to a comparative pharmacokinetic study following oral administration of PR, GR, and PR-GR aqueous extracts in rats. The effect of GR on the absorption of components of PR was also investigated by single-pass intestinal perfusion study. Results showed that comparing to the single herbs, PR-GR extract significantly increased the systemic exposure of puerarin, 3′-hydroxypuerarin, 3′-methoxypuerarin, 6″-O-xylosylpuerarin, daidzin, genistein, and gastrodin. Moreover, the intestinal absorption of puerarin and daidzin could be improved by GR extract and inhibitors of P-glycoprotein and multidrug resistanceassociated protein 2, respectively. These results indicate that the combination of PR and GR increases the levels of their bioactive ingredients exposed in the blood, and GR increases the absorption of ingredients of PR may by inhibition of the efflux mediated by P-glycoprotein and multidrug resistanceassociated protein 2. This is the first report for the pharmacokinetics and intestinal absorption of PR-GR, which may explain their synergetic effects in the treatment of circulatory systematic diseases and provide a meaningful insight for their clinical applications.

Bortezomib-loaded solid lipid nanoparticles: preparation, characterization, and intestinal permeability investigation

Bortezomib (BTZ), a proteasome inhibitor, is clinically used for the treatment of multiple myeloma and mantle cell lymphoma via intravenous or subcutaneous administration. Since BTZ has limited intestinal permeability, in this study, solid lipid nanoparticles (SLNs) were selected as lipid carrier to improve the intestinal permeability of BTZ. The nanoparticles were prepared by hot oil-in-water emulsification method and characterized for physicochemical properties. Moreover, in situ single-pass intestinal perfusion technique was used for intestinal permeability studies. Mean particle size of the BTZ-loaded solid lipid nanoparticles (BTZ-SLNs) was 94.6 ± 0.66 nm with a negative surface charge of –18 ± 11 mV. The entrapment efficiency of the BTZ-SLNs was 68.3 ± 3.7% with a drug loading value of 0.8 ± 0.05%. Cumulative drug release (%) over 48 h, indicated a slow release pattern for nanoparticles. Moreover, the SEM image showed a spherical shape and uniform size distribution for nanoparticles. Also, FTIR analysis indicated that BTZ was successfully loaded in the SLNs. The results of the intestinal perfusion studies revealed an improved effective permeability for BTZ-SLNs with a Peff value of about threefold higher than plain BTZ solution.

Evaluating the intestinal and oral absorption of the prodrug valacyclovir in wildtype and huPepT1 transgenic mice

The purpose of this work was to evaluate the intestinal permeability, oral absorption and disposition of the ester prodrug valacyclovir in wildtype mice and a huPepT1 transgenic mouse model. PepT1 (SLC15A1) is a transporter apically expressed along the lumen of the gastrointestinal tract and is responsible for the absorption of di-/tripeptides, ACE inhibitors, β-lactam antibiotics and numerous prodrugs. Unfortunately, PepT1-mediated substrates that have been extensively studied were shown to exhibit species-dependent absorption and pharmacokinetics. Accordingly, in situ intestinal perfusion studies were conducted and valacyclovir uptake was shown to have a 30-fold lower Km and 100-fold lower Vmax in huPepT1 compared to wildtype mice. Moreover, inhibition studies demonstrated that the huPepT1 transporter alone was responsible for valacyclovir uptake, and segment-dependent studies reported significant reductions in permeability along the length of small intestine in huPepT1 mice. Subsequent oral administration studies revealed that the in vivo rate and extent of valacyclovir absorption were lower in huPepT1 mice, as indicated by 3-fold lower Cmax and 3-fold higher Tmax values, and an AUC0-180 that was 80% of that observed in wildtype mice. However, no significant changes in drug disposition were observed between genotypes after intravenous bolus administration of acyclovir. Lastly, mass balance studies established that the bioavailability of acyclovir, after oral dosing of valacyclovir, was 77.5% in wildtype mice and 52.8% in huPepT1 mice, which corroborated values of 51.3% in clinical studies. Thus, it appears the huPepT1 transgenic mice may be a better model to study prodrug absorption and disposition in humans than wildtype mice.

Covalently mucoadhesive amphiphilic prodrug of 5-fluorouracil for enhanced permeation and improved oral absorption.

5-Fluorouracil (5-FU) is one of the important antitumor drugs and is widely used to treat various types of cancers. However, its administration is limited to intravenous route due to poor oral bioavailability. Herein, we hypothesized that the maleimide group-containing 5-FU prodrug (EMC-5-FU) could improve the intestinal mucoadhesion because the maleimide end group can covalently target thiol residues of mucin glycoprotein covering the intestinal enterocytes. In vitro bioadhesion results showed that EMC-5-FU exhibited good affinity to the cysteine-rich subdomains of mucin and NMR studies successfully verified the covalent attachment of EMC-5-FU to mucin. The intestinal perfusion study indicated that the intestinal bioadhesion and membrane permeability are greatly enhanced for EMC-5-FU, in comparison with 5-FU. Mucoadhesion investigations on rat intestine intuitively confirmed increased intestinal retention of 5-FU through maleimide-mediated mucoadhesion. Moreover, AUC0-24h of the total 5-FU level for EMC-5-FU solution was 2.65-fold higher compared with 5-FU solution. Our study further suggested that the amphiphilic prodrug EMC-5-FU with good mucoadhesion is a promising delivery strategy form to overcome multiple barriers of oral absorption.

Intestinal absorption and activation of decitabine amino acid ester prodrugs mediated by peptide transporter PEPT1 and enterocyte enzymes

Decitabine (DAC), a potent DNA methyltransferase (DNMT) inhibitor, has a limited oral bioavailability. Its 5′-amino acid ester prodrugs could improve its oral delivery but the specific absorption mechanism is not yet fully understood. The aim of this present study was to investigate the in vivo absorption and activation mechanism of these prodrugs using in situ intestinal perfusion and pharmacokinetics studies in rats. Although PEPT1 transporter is pH dependent, there appeared to be no proton cotransport in the perfusion experiment with a preferable transport at pH 7.4 rather than pH 6.5. This suggested that the transport was mostly dependent on the dissociated state of the prodrugs and the proton gradient might play only a limited role. In pH 7.4 HEPES buffer, an increase in Peff was observed for L-val-DAC, D-val-DAC, L-phe-DAC and L-trp-DAC (2.89-fold, 1.2-fold, 2.73-fold, and 1.90-fold, respectively), compared with the parent drug. When co-perfusing the prodrug with Glysar, a known substrate of PEPT1, the permeabilities of the prodrugs were significantly inhibited compared with the control. To further investigate the absorption of the prodrugs, L-val-DAC was selected and found to be concentration-dependent and saturable, suggesting a carrier-mediated process (intrinsic Km: 7.80 ± 2.61 mM) along with passive transport. Determination of drug in intestinal homogenate after perfusion further confirmed that the metabolic activation mainly involved an intestinal first-pass effect. In a pharmacokinetic evaluation, the oral bioavailability of L-val-DAC, L-phe-DAC and L-trp-DAC were nearly 1.74-fold, 1.69-fold and 1.49-fold greater than that of DAC. The differences in membrane permeability and oral bioavailability might be due to the different stability in the intestinal lumen and the distinct PEPT1 affinity which is mainly caused by the stereochemistry, hydrophobicity and steric hindrance of the side chains. In summary, the detailed investigation of the absorption mechanism by in vivo intestinal perfusion and pharmacokinetic studies showed that the prodrugs of DAC exhibited excellent permeability and oral bioavailability, which might be attributed to a hybrid (partly PEPT1-mediated and partly passive) transport mode and a rapid activation process in enterocytes.

Targeted intestinal delivery of incretin secretagogues—towards new diabetes and obesity therapies

A new strategy under development for the treatment of type 2 diabetes and obesity is to mimic some of the effects of bariatric surgery by delivering food-related stimuli to the distal gastrointestinal tract where they should enhance the release of gut hormones such as glucagon-like peptide-1 (GLP-1) and peptideYY (PYY). Methods include inhibition of food digestion and absorption in the upper GI tract, or oral delivery of stimuli in capsules or pelleted form to protect them against gastric degradation. A variety of agents have been tested in humans using capsules, microcapsules or pellets, delivering nutrients, bile acids, fatty acids and bitter compounds. This review examines the outcomes of these different approaches and supporting evidence from intestinal perfusion studies.

P-gp is involved in the intestinal absorption and biliary excretion of afatinib in vitro and in rats.

Afatinib is an irreversible multi-targeted TKI, used in the treatment with EGFR mutated non-small cell lung cancer (NSCLC). The purpose of this study is to explore the molecular pharmacokinetic mechanism underlying the effect of P-gp inhibitors on the intestinal absorption and biliary excretion and to understand how P-gp inhibitors affect afatinib pharmacokinetics. Pharmacokinetics in vivo, in situ intestinal perfusion, perfused rat liver in situ, Caco-2 cells, P-gp ATPase activity, sandwich-cultured rat hepatocytes (SCRH) and transfected-cell transport were used in the evaluation. P-gp inhibitor verapamil (Ver) markedly increased the plasma concentrations and significantly decreased the biliary excretion of afatinib in vivo. Ver increased the intestinal absorption and decreased biliary excretion of afatinib in situ single-pass intestinal perfusion studies and in situ perfused rat liver, respectively. The accumulation of afatinib in Caco-2 cells was enhanced by Ver and Cyclosporin A (CsA). The biliary excretion index (BEI) of afatinib in SCRH was decreased by Ver and CsA, respectively. The net efflux ratio of afatinib was 2.3 across vector-/MDR1-MDCKII cell monolayers and was decreased by P-gp inhibitor. The activity of P-gp ATPase was induced by afatinib and the Km and Vmax were 1.05μM and 59.88nmol ATP/mg hP-gp/min, respectively. At least partly P-gp is involved in increasing the intestinal absorption and decreasing the biliary excretion of afatinib in rats.

Polymeric nanoparticles developed by vitamin E-modified aliphatic polycarbonate polymer to promote oral absorption of oleanolic acid

Oleanolic acid (OA) exhibited good pharmacological activities in the clinical treatment of hypoglycemia, immune regulation, acute jaundice and chronic toxic hepatitis. However, the oral delivery of OA is greatly limited by its inferior water solubility and poor intestinal mucosa permeability. Herein, we developed a novel polymeric nanoparticle (NP) delivery system based on vitamin E modified aliphatic polycarbonate (mPEG-PCC-VE) to facilitate oral absorption of OA. OA encapsulated mPEG-PCC-VE NPs (OA/mPEG-PCC-VE NPs) showed uniform particle size of about 170 nm with high drug loading capability (8.9%). Furthermore, the polymeric mPEG-PCC-VE NPs, with good colloidal stability and pH-sensitive drug release characteristics, significantly enhanced the in vitro dissolution of OA in the alkaline medium. The in situ single pass intestinal perfusion (SPIP) studies performed on rats demonstrated that the OA/mPEG-PCC-VE NPs showed significantly improved permeability in the whole intestinal tract when compared to OA solution, especially for duodenum and colon. As a result, the in vivo pharmacokinetics study indicated that the bioavailability of OA/mPEG-PCC-VE NPs showed 1.5-fold higher than commercially available OA tablets. These results suggest that mPEG-PCC-VE NPs are a promising platform to facilitate the oral delivery of OA.

Improving intestinal absorption and oral bioavailability of curcumin via taurocholic acid-modified nanostructured lipid carriers.

The expression of multiple receptors on intestinal epithelial cells enables an actively targeted carrier to significantly enhance the oral delivery of payloads. Conjugating the receptors’ ligands on the surfaces of a particulate-delivery system allows site-specific targeting. Here, we used taurocholic acid (TCA) as a ligand for uptake of nanostructured lipid carriers (NLCs) mediated by a bile-acid transporter to improve oral bioavailability of curcumin (Cur). First, synthesis of TCA–polyethylene glycol 100–monostearate (S100-TCA) was carried out. Then, the physical and chemical properties of S100-TCA-modified Cur-loaded NLCs (Cur-TCA NLCs) with varying levels of S100-TCA modifications were investigated. Small particle size (<150 nm), high drug encapsulation (>90%), drug loading (about 3%), negative ζ-potential (−7 to −3 mV), and sustained release were obtained. In situ intestinal perfusion studies demonstrated improved absorption rate and permeability coefficient of Cur-TCA NLCs. Depending on the degree of modification, Cur-TCA NLCs displayed about a five- to 15-fold higher area under the curve in rats after oral administration than unmodified Cur NLCs, which established that the addition of S100-TCA to the NLCs boosted absorption of Cur. Further investigations of TCA NLCs might reveal a bright future for effective oral delivery of poorly bioavailable drugs.

Long-chain triglycerides-based self-nanoemulsifying oily formulations (SNEOFs) of darunavir with improved lymphatic targeting potential

The current studies entail systematic development of SNEOFs containing long-chain triglycerides for improving lymphatic targeting of darunavir for complete inhibition of HIV progression. As per QbD-oriented approach for formulation development, the QTPP was defined and CQAs were earmarked. Preformulation equilibrium solubility and phase diagram studies, and risk assessment through FMEA studies identified Lauroglycol 90, Tween 80 and Transcutol HP as the lipid, emulgent and cosolvent, respectively, for formulating SNEOFs of darunavir. Systematic optimisation of SNEOFs was conducted using IV-optimal mixture design, and the optimised formulation was chosen through numerical desirability function. Characterisation of optimised SNEOFs exhibited globule size of 50 nm, >85% drug release within 15 min and >75% permeation within 45 min. In vivo lymph cannulation and in situ intestinal perfusion studies indicated significant improvement in the drug absorption parameters from SNEOFs via intestinal lymphatic pathways, owing primarily to the presence of long-chain triglycerides. Also, in vivo pharmacokinetic studies in rat corroborated significant improvement in rate and extent of drug absorption into plasma vis-à-vis pure drug. In a nutshell, these studies indicate significant improvement in the biopharmaceutical attributes of a robust and stable SNEOFs formulation of darunavir for holistic management of viral loads in lymph and blood.

Enhanced Oral Bioavailability of Diltiazem by the Influence of Gallic Acid and Ellagic Acid in Male Wistar Rats: Involvement of CYP3A and P-gp Inhibition.

The oral bioavailability of diltiazem is very low due to rapid first pass metabolism in liver and intestine. The purpose of the study was to investigate the effect of gallic acid and ellagic acid on intestinal transport and oral bioavailability of diltiazem in rats. The intestinal transport and permeability of diltiazem was evaluated by in vitro non-everted sac method and in situ single pass intestinal perfusion study. The oral pharmacokinetics was evaluated by conducting oral bioavailability study. The intestinal transport and apparent permeability of diltiazem were significantly enhanced in duodenum, jejunum, and ileum of gallic and ellagic acid-treated groups. The effective permeability of diltiazem was significantly enhanced in ileum part of gallic and ellagic acid-treated groups. When compared with control group, the presence of these two phytochemicals significantly enhanced the area under plasma concentration-time curve and the peak plasma concentration of diltiazem (Cmax ). Gallic acid and ellagic acid significantly increased the bioavailability of diltiazem due to the inhibition of both CYP3A-mediated metabolism and P-glycoprotein-mediated efflux in the intestine and/or liver. Based on these results, the clinical experiments are warranted for the confirmation to reduce the dose of diltiazem when concomitantly administered with these phytochemicals. Copyright © 2017 John Wiley & Sons, Ltd.

Intestinal Permeability and Role of P-Glycoprotein in Intestinal Absorption of Novel Triethylamine Containing Thiophene S006–830 Using Single-Pass Intestinal Perfusion in Rats

Aim: Study was designed to develop ultra-fast liquid chromatography method of antitubercular compound S006–830 in rat intestinal perfusate and apply method for determination of effective permeability coefficient (Peff), absorption rate (Ka) and role of P-glycoprotein (P-gp) in the absorption. Methods: Chromatography was performed. Peff, Ka of S006–830, role of P-gp in the absorption of S006–830 were determined by single-pass intestinal perfusion studies. Results: Method was found sensitive, reproducible. Recoveries of S006–830 were found around 60%. Method was applied for determination of Peff and Ka. Peff and Ka values indicated that S006–830 possesses high permeability and high absorption rate. Conclusion: Co-infusion of S006–830 with verapamil in single pass intestinal perfusion study demonstrated that P-gp do not have any significant role in the absorption of S006–830.

Sulfotransferases and Breast Cancer Resistance Protein Determine the Disposition of Calycosin in Vitro and in Vivo

Sulfation is a key process of drug disposition that generally regulates drug effectiveness and toxicity. Calycosin derived from the dry root extract of Radix Astragali exhibits a variety of biological effects that easily undergo extensive phase II metabolism. However, the sulfation pathway of calycosin lacks information. We investigated the disposition mechanisms of calycosin sulfate in vitro and in vivo. We characterized the sulfation metabolism and excretion of calycosin using bidirectional transport studies. We confirmed that sulfate conjugate is breast cancer resistance protein (BCRP) substrate using the intestinal perfusion model and pharmacokinetics studies in Bcrp1-/- mice. Results showed that calycosin is rapidly and extensively metabolized to calycosin-3'-sulfate (C-3'-S) in the intestine and liver. The overexpression of BCRP led to a substantial increase (approximately 14-fold, p < 0.01) of excreted C-3'-S in the BCRP overexpressed Madin-Darby canine kidney II (MDCK II/BCRP) cells. The chemical inhibition of BCRP caused reduction (about 2-fold, p < 0.01) in C-3'-S apical excretion. Furthermore, in intestinal perfusion studies, the deletion of Bcrp1 significantly decreased C-3'-S excretion in the small intestine (82.6-90.6%, p < 0.01) and colon (97.6-98.2%, p < 0.01). In contrast, plasma level of C-3'-S was increased to 40-fold (p < 0.01) in Bcrp1-/- mice. In conclusion, calycosin undergoes an extensive sulfation metabolism and BCRP is a critical determinant to the disposition of C-3'-S.

Capsaicin pretreatment enhanced the bioavailability of fexofenadine in rats by P-glycoprotein modulation: in vitro, in situ and in vivo evaluation

Background and objective: Capsaicin is the main pungent principle present in chili peppers has been found to possess P-glycoprotein (P-gp) inhibition activity in vitro, which may have the potential to modulate bioavailability of P-gp substrates. Therefore, purpose of this study was to evaluate the effect of capsaicin on intestinal absorption and bioavailability of fexofenadine, a P-gp substrate in rats.Methods: The mechanistic evaluation was determined by non-everted sac and intestinal perfusion studies to explore the intestinal absorption of fexofenadine. These results were confirmed by an in vivo pharmacokinetic study of oral administered fexofenadine in rats.Results: The intestinal transport and apparent permeability (Papp) of fexofenadine were increased significantly by 2.8 and 2.6 fold, respectively, in ileum of capsaicin treated rats when compared to control group. Similarly, absorption rate constant (Ka), fraction absorbed (Fab) and effective permeability (Peff) of fexofenadine were increased significantly by 2.8, 2.9 and 3.4 fold, respectively, in ileum of rats pretreated with capsaicin when compared to control group. In addition, maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) were increased significantly by 2.3 and 2.4 fold, respectively, in rats pretreated with capsaicin as compared to control group. Furthermore, obtained results in rats pretreated with capsaicin were comparable to verapamil (positive control) treated rats.Conclusions: Capsaicin pretreatment significantly enhanced the intestinal absorption and bioavailability of fexofenadine in rats likely by inhibition of P-gp mediated cellular efflux, suggesting that the combined use of capsaicin with P-gp substrates may require close monitoring for potential drug interactions.

Enhanced Oral Bioavailability of Domperidone with Piperine in Male Wistar Rats: Involvement of CYP3A1 and P-gp Inhibition.

Domperidone is a commonly used antiemetic drug. The oral bioavailability of domperidone is very low due to its rapid first pass metabolism in the intestine and liver. Piperine, the main alkaloid present in black pepper has been reported to show inhibitory effects on Cytochrome P-450 (CYP-450) enzymes and P-glycoprotein (P-gp). In the present study we investigated the effect of piperine pretreatment on the intestinal transport and oral bioavailability of domperidone in male Wistar rats. The intestinal transport of domperidone was evaluated by an in-vitro non-everted sac method and in-situ single pass intestinal perfusion (SPIP) study. The oral pharmacokinetics of domperidone was evaluated by conducting oral bioavailability study in rats. A statistically significant improvement in apparent permeability (Papp) was observed in rats pretreated with piperine compared to the respective control group. The effective permeability (Peff) of domperidone was increased in the ileum of the piperine treated group. Following pretreatment with piperine, the peak plasma concentration (Cmax) and area under the concentration- time curve (AUC) were significantly increased. A significant decrease in time to reach maximum plasma concentration (Tmax), clearance and elimination rate constant (Kel) was observed in rats pretreated with piperine. Piperine enhanced the oral bioavailability of domperidone by inhibiting CYP3A1 and P-gp in rats. This observation suggests the possibility that the combination of piperine with other CYP3A4 and P-gp dual substrates may also improve bioavailability. Further clinical studies are recommended to verify this drug interaction in human volunteers and patients.This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Exploring and validating physicochemical properties of mangiferin through GastroPlus® software.

Aim:Mangiferin (Mgf), a promising therapeutic polyphenol, exhibits poor oral bioavailability. Hence, apt delivery systems are required to facilitate its gastrointestinal absorption. The requisite details on its physicochemical properties have not yet been well documented in literature. Accordingly, in order to have explicit insight into its physicochemical characteristics, the present work was undertaken using GastroPlus™ software.Results:Aqueous solubility (0.38 mg/ml), log P (-0.65), Peff (0.16 × 10-4 cm/s) and ability to act as P-gp substrate were defined. Potency to act as a P-gp substrate was verified through Caco-2 cells, while Peff was estimated through single pass intestinal perfusion studies. Characterization of Mgf through transmission electron microscopy, differential scanning calorimetry, infrared spectroscopy and powder x-ray diffraction has also been reported.Conclusion:The values of physicochemical properties for Mgf reported in the current manuscript would certainly enable the researchers to develop newer delivery systems for Mgf.

Characterization and evaluation of a self-microemulsifying drug delivery system containing tectorigenin, an isoflavone with low aqueous solubility and poor permeability

The purpose of this study was to characterize and evaluate tectorigenin-loaded self-microemulsifying drug delivery system (TG-SMEDDS), a previously studied preparation, and further confirm the improvement of TG in solubility and bioavailability. The appearance of TG-SMEDDS was clear and transparent, with good mobility. The microemulsion formed by TG-SMEDDS was globular, edge smooth, clear-cut, and distribution homogeneous under transmission electron microscope. The stability studies revealed that TG-SMEDDS remained stable at room temperature for at least 3 months. TG-SMEDDS showed excellent dissolution behavior that more than 90% of TG was released in only 5 min. The in situ intestinal perfusion studies indicated enhancement of absorption in four tested intestinal segments, and the main absorption site of TG was changed to duodenum. In addition, TG-SMEDDS showed significantly higher Cmax and AUC values (11-fold and 5-fold higher values, respectively; P < 0.05) than TG, and the absolute oral bioavailability of TG-SMEDDS was 56.33% (5-fold higher than that of crude TG). What’s more, the AUC0-t of crude TG and TG-SMEDDS in bile duct non-ligation rats were 6.05 and 2.80 times, respectively, than that in bile duct ligation rats, indicating the existence of enterohepatic circulation and the secretion of bile could significantly affect the absorption of TG. Further studies showed that even the bile duct was ligation, TG-SMEDDS can still keep a better oral bioavailability (179.67%, compared with crude TG in the bile duct non-ligation rats). Therefore, our study implies that SMEDDS containing TG could be an effective strategy for the oral administration of TG.

N-acetyl-L-cysteine functionalized nanostructured lipid carrier for improving oral bioavailability of curcumin: preparation, in vitro and in vivo evaluations

The application of orally administered nanoparticles in the circulation system is limited by the secretion and shedding of intestinal tract mucous layer. In order to enhance mucoadhesion and mucus penetration of curcumin (Cur)-loaded nanostructured lipid carrier (NLC) after oral administration, a new multifunctional conjugate, N-acetyl-L-cysteine-polyethylene glycol (100)-monostearate (NAPG), was synthesized. Functionalized nanocarriers (Cur-NAPG-NLC) modified by different amounts of NAPG (the amounts of NAPG were 20, 50, and 100 mg) were prepared and investigated for in vitro and in vivo behavior. Mean particle sizes of 89–141 nm with negative zeta potential (−15 to −11 mV) and high encapsulation efficiency (EE, >90%) possessing spherical and stable nanocarriers were observed. Sustained drug release was also observed for the NAPG-NLC. In situ intestinal perfusion studies showed that with increasing the amount of NAPG increase absorption of Cur. In vivo oral pharmacokinetic evaluation suggested that the bioavailability of Cur in rats was proportional to the degree of functionalization of NLCs with NAPG. AUC0–t of Cur-NAPG100-NLC was improved by 499.45 and 116.89 folds as compared to that of Cur solution and unmodified Cur-NLC, respectively. In conclusion, NAPG modified NLC could be a promising drug delivery system for improving oral performance of BCS class IV drugs.

A combination of complexation and self-nanoemulsifying drug delivery system for enhancing oral bioavailability and anticancer efficacy of curcumin

Objective: Curcumin, the golden spice from Indian saffron, has shown chemoprotective action against many types of cancer including breast cancer. However, poor oral bioavailability is the major hurdle in its clinical application. In the recent years, self-nanoemulsifying drug delivery system (SNEDDS) has emerged as a promising tool to improve the oral absorption and enhancing the bioavailability of poorly water-soluble drugs. In this context, complexation with lipid carriers like phospholipid has also shown the tremendous potential to improve the solubility and therapeutic efficacy of certain drugs with poor oral bioavailability.Methods: In the present investigation, a systematic combination of both the approaches is utilized to prepare the phospholipid complex of curcumin and facilitate its incorporation into SNEDDS. The combined use of both the approaches has been explored for the first time to enhance the oral bioavailability and in turn increase the anticancer activity of curcumin.Results: As evident from the pharmacokinetic studies and in situ single pass intestinal perfusion studies in Sprague–Dawley rats, the optimized SNEDDS of curcumin–phospholipid complex has shown enhanced oral absorption and bioavailability of curcumin. The cytotoxicity study in metastatic breast carcinoma cell line has shown the enhancement of cytotoxic action by 38.7%. The primary tumor growth reduction by 58.9% as compared with the control group in 4T1 tumor-bearing BALB/c mice further supported the theory of enhancement of anticancer activity of curcumin in SNEDDS.Conclusion: The developed formulation can be a potential and safe carrier for the oral delivery of curcumin.

Intestinal transport of HDND-7, a novel hesperetin derivative, in in vitro MDCK cell and in situ single-pass intestinal perfusion models

1. Hesperetin (HDND) possesses extensive bioactivities, however, its poor solubility and low bioavailability limit its application. HDND-7, a derivative of HDND, has better solubility and high bioavailability. In this study, we investigated the intestinal absorption mechanisms of HDND-7.2. MDCK cells were used to examine the transport mechanisms of HDND-7 in vitro, and a rat in situ intestinal perfusion model was used to characterize the absorption of HDND-7. The concentration of HDND-7 was determined by HPLC.3. In MDCK cells, HDND-7 was effectively absorbed in a concentration-dependent manner in both directions. Moreover, HDND-7 showed pH-dependent and TEER-independent transport in both directions. The transport of HDND-7 was significantly reduced at 4 °C or in the presence of NaN3. Furthermore, the efflux of HDND-7 was apparently reduced in the presence of MRP2 inhibitors MK-571 or probenecid. However, P-gp inhibitor verapamil had no effect on the transport of HDND-7. The in situ intestinal perfusion study indicated HDND-7 was well-absorbed in four intestinal segments. Furthermore, MRP2 inhibitors may slightly increase the absorption of HDND-7 in jejunum.4. In summary, all results indicated that HDND-7 might be absorbed mainly by passive diffusion via transcellular pathway, MRP2 but P-gp may participate in the efflux of HDND-7.