Intestinal Perfusion Technique Research Articles

Psidium guajava leaves extract alters colonic microbiome composition and reduces intestinal sodium absorption in rats exposed to a high-sodium diet.

High sodium intake is a major risk factor for hypertension and renal diseases. Previous studies have shown that a suspension of ethanolic extract of Psidium guajava (guava) leaves (PsE) has antihypertensive effects in rats on a high-sodium diet (HSD), but some mechanisms to that remain unexplored. This study explored whether oral PsE treatment affects sodium handling by the intestine and alters the gut microbiome in HSD-fed rats. Male Wistar rats were divided into two groups: standard salt diet (SSD) and HSD (0.9% Na+), from weaning. After 12 weeks, both groups received PsE (200mg/kg) or a vehicle for an additional 4 weeks. Sodium excretion was measured using flame photometry, and sodium absorption was assessed by intestinal perfusion technique. The gut microbiome was analysed through 16S ribosomal gene sequencing. HSD increased faecal sodium, further elevated by PsE, which inhibited intestinal sodium absorption in HSD rats. HSD altered the abundance of specific bacterial families, which PsE partially reversed. No changes in alpha diversity were noted among groups. These findings suggest that PsE inhibited intestinal sodium handling and that PsE, combined with increased faecal sodium, may reshape the gut microbiome of HSD rats to resemble that of SSD rats.

In situ evaluation of the impact of metformin or verapamil coadministration with vildagliptin on its regional absorption from the rabbit's intestine.

This research aims to identify regional differences in vildagliptin absorption across the intestinal membrane. Furthermore, it was to investigate the effect of verapamil or metformin on vildagliptin absorptive clearance. The study utilized an in situ rabbit intestinal perfusion technique to determine vildagliptin oral absorption from duodenum, jejunum, ileum, and ascending colon. This was conducted both with and without perfusion of metformin or verapamil. The findings revealed that the vildagliptin absorptive clearance per unit length varied by site and was in the order as follows: ileum<jejunum<duodenum<ascending colon, implying that P-gp is significant in the reduction of vildagliptin absorption. Also, the arrangement cannot reverse intestinal P-gp, but the observations suggest that P-gp is significant in reducing vildagliptin absorption. Verapamil co-perfusion significantly increased the vildagliptin absorptive clearance by 2.4 and 3.2 fold through the jejunum and ileum, respectively. Metformin co-administration showed a non-significant decrease in vildagliptin absorptive clearance through all tested segments. Vildagliptin absorption was site-dependent and may be related to the intestinal P-glycoprotein content. This may aid in understanding the important elements that influence vildagliptin absorption, besides drug-drug interactions that can occur in type 2 diabetic patients taking vildagliptin in conjunction with other drugs that can modify the P-glycoprotein level.

Impact of the Unstirred Water Layer on the Permeation of Small-Molecule Drugs.

Over the last two decades, numerous molecular dynamics (MD) simulation-based investigations have attempted to predict the membrane permeability to small-molecule drugs as indicators of their bioavailability, a majority of which utilize the inhomogeneous solubility diffusion (ISD) model. However, MD-based membrane permeability is routinely 3-4 orders of magnitude larger than the values measured with the intestinal perfusion technique. There have been contentious discussions on the sources of the large discrepancies, and the two indisputable, potentially dominant ones are the fixed protonation state of the permeant and the neglect of the unstirred water layer (UWL). Employing six small-molecule drugs of different biopharmaceutical classification system classes, the current MD study relies on the ISD model but introduces the (de)protonation of the permeant by characterizing the permeation free energy of both neutral and charged states. In addition, the role of the UWL as a potential resistance against permeation is explored. The new MD protocol closely mimics the nature of small-molecule permeation and yields estimates that agree well with in vivo intestinal permeability.

Estimation of Human Oral Fraction Dose Absorbed of Simvastatin from Various Formulations using in-situ Single Pass Intestinal Perfusion Method

Background: SIM is a poorly water-soluble drug with dissolution-dependent bioavaila-bility. A solid dispersion and self-emulsifying drug delivery system was developed, optimized, and evaluated to improve its bioavailability. The permeability coefficient in rats was determined using the in-situ single-pass intestinal perfusion (SPIP) technique. Further, the permeability coefficient (Peff, humans) was used to calculate the permeability and fraction of SIM bioavailable to humans which have not yet been reported for these formulations. Objective: To estimate and compare various formulations of Simvastatin (SIM) for bioavailable fraction to humans (Fa) as a function of solubility enhancement. Methods: In this study, the preparation and evaluation of SIM formulations i.e., Self-emulsifying drug delivery system (SEDDS) and Solid dispersions (SD) are discussed in brief. An uncomplicat-ed, precise, and accurate HPLC method was validated for simultaneous determination of SIM and phenol red as per ICH guidelines. A comparative in-vitro dissolution test, pharmacokinetic studies, and in-situ SPIP technique in rats were carried out amongst optimized formulations of SIM-SD and SIM-SEDDS, SIM suspension (SIM-SUSP), and SIM marketed preparation (SIM-MP). Results: The HPLC method was successfully validated. In-vitro dissolution test displays that both the SIM formulations i.e., SIM-SEDDS and SIM-SD shows better dissolution rate than SIM-MP and SIM-SUSP. Pharmacokinetic studies revealed that SIM-SEDDS, SIM-SD, and SIM-MP showed significant differences when compared to SIM-SUSP in terms of Cmax, [AUC] 0-∞, at P ≤ 0.05. The comparison of permeability coefficient between SIM SEDDS vs. SIM MP and SIM SEDDS vs. SIM SD were non-significant. In contrast, SIM- SUSP vs. all other formulations were significantly different at P ≤ 0.05 (employing two-way ANOVA followed by post-Bonferroni Test). Fa for SIM SUSP, an optimized formulation of SIM-SEDDS, SIM-MP, and SIM-SD are 0.353, 0.977, 0.975, and 0.987 respectively. It is revealed that SIM-SEDDS and SIM-SD showed enhanced absorption and the results are confirmed by in-vitro data, pharmacokinetic studies, and In-situ SPIP techniques. Conclusion: The permeability prediction method is a rapid and economical method for screening chemical compounds with the least possible utilization of resources. So, its use can be extended in prime and initial screening prototypes for the evaluation of compounds in the early stages of their formulations.

Evaluation of Intestinal Drug Absorption and Interaction Using Quadruple Single-Pass Intestinal Perfusion Coupled with Mass Spectrometry Imaging.

Visualization and characterization of the intestinal membrane transporter-mediated drug absorption and interaction are challenging due to the complex physical and chemical environment. In this work, an integrated strategy was developed for in situ visualization and assessment of the drug absorption and interaction in rat intestines using quadruple single-pass intestinal perfusion (Q-SPIP) technique coupled with matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI). Compared with the traditional SPIP only available for perfusion of one single intestinal segment, the Q-SPIP model can simultaneously perfuse four individual segments of each rat intestine (duodenum, jejunum, ileum, and colon), enabling to obtain rich data from one rat. Subsequently, the drug distribution and absorption in rat intestinal tissue were accurately visualized by using an optimized MALDI MSI approach. The utility and versatility of this strategy were demonstrated via the examination of P-glycoprotein (P-gp)-mediated intestinal absorption of berberine (BBR) and its combination with natural products possessing inhibitory potency against P-gp. The change in the spatial distribution of BBR was resolved, and MALDI results showed that the signal intensity of BBR in defined regions was enhanced following coperfusion with P-gp inhibitors. However, enhanced absorption of BBR after coperfusion with the P-gp inhibitor was not observed in the ulcerative colitis rat model, which may be due to the damage to the intestinal barrier. This study exemplifies the availability and utility of Q-SPIP coupled with MALDI MSI in the examination of transporter-mediated intestinal drug absorption and interaction for fundamental inquiries into the preclinical prediction of oral absorption and drug interaction potential.

Intestinal absorption pathways of lisinopril: Mechanistic investigations.

Lisinopril is an antihypertensive drug with poor intestinal permeability. Enhancement of intestinal absorption depends on a clear understanding of the permeation pathways and absorption mechanisms. Unfortunately, these are not fully elucidated for lisinopril. Accordingly, the aim was to determine lisinopril permeation pathways and obstacles limiting membrane transport with subsequent nomination of appropriate permeation enhancers. This employed an in situ rabbit intestinal perfusion technique, which revealed site-dependent absorptive clearance (PeA/L) from a lisinopril simple solution (5μg/ml), with paracellular absorption playing a role. Regional drug permeability ranked as colon>duodenum>jejunum>ileum opposing intestinal expression rank of P-glycoprotein (P-gp) efflux transporters. Duodenal and jejunal perfusion of a higher lisinopril concentration (50μg/ml) reflected saturable absorption, suggesting carrier-mediated transport. The effect of piperine and verapamil as P-gp inhibitors on intestinal absorption of lisinopril was investigated. Coperfusion with either piperine or verapamil significantly enhanced lisinopril absorption, with enhancement being dominant in the ileum segment. This supported the contribution of P-gp transporters to poor lisinopril permeability. On the other hand, coperfusion of lisinopril with zinc acetate dihydrate significantly multiplied lisinopril PeA/L by 2.3- and 6.6-fold in duodenum and ileum segments, respectively, through magnifying intestinal water flux. The study explored the barriers limiting lisinopril intestinal absorption. Moreover, the study exposed clinically relevant lisinopril interactions with common coadministered cargos that should be considered for an appropriate lisinopril regimen. However, this requires further in vivo verification.

Cubosomes for Enhancing Intestinal Absorption of Fexofenadine Hydrochloride: In situ and in vivo Investigation.

PurposeThe aim of this work was to probe cubosomes for enhanced intestinal absorption and oral bioavailability of poorly absorbable fexofenadine HCl (FEX-HCl).Materials and MethodsTwo cubosomal systems were fabricated utilizing glyceryl mono-oleate, a lyotropic mono lamellar lipid as oil phase and poloxamer407 as stabilizer at weight ratios of 8:2 and 7:3. The morphology of cubosomes was researched using transmission electron microscopy (TEM) and particle size was measured using photon correlation spectroscopy. FEX-HCl release was monitored in vitro. The effect of cubosomal encapsulation on intestinal absorption was assessed using in situ rabbit intestinal perfusion technique. Carrageenan induced rat paw edema model was utilized to monitor in vivo anti-inflammatory effect before and after cubosomal encapsulation.ResultsTEM revealed the existence of spherical and polygonal nanostructures arranged in honeycomb organization. Size measurement reflected nanoparticles with reduced size at higher poloxamer concentration. Release studies revealed liberation of FEX-HCl from cubosomes based on Higuchi kinetics model. The intestinal permeability data indicated incomplete absorption of FEX-HCl from simple aqueous solution with P-glycoprotein efflux contributing to this poor intestinal absorption. Incorporation of FEX-HCl in cubosomes enhanced membrane transport parameters. The intestinal absorption did not correlate with drug release suggesting that drug release is not the rate limiting with possible intact cubosomal transport. Cubosomal encapsulation of FEX-HCl significantly enhanced its in vivo anti-inflammatory efficacy compared to the aqueous FEX-HCl dispersion.ConclusionCubosomes are promising novel carriers for enhancing intestinal absorption of FEX-HCl. Intact FEX-HCl-cubosomal absorption is possible via trans-lymphatic pathway but this requires further investigations.

Lopinavir-menthol co-crystals for enhanced dissolution rate and intestinal absorption

Lopinavir is an antiretroviral, antiparasitic agent and recently utilized in treatment of COVID-19. Unfortunately, lopinavir exhibited poor oral bioavailability due to poor dissolution, extensive pre-systemic metabolism, and significant P-glycoprotein intestinal efflux. Accordingly, the aim was to enhance dissolution rate and intestinal absorption of lopinavir. This employed co-processing with menthol which is believed to modify crystalline structures and inhibit intestinal efflux. Lopinavir was mixed with menthol at different molar ratios before ethanol assisted kneading. Formulations were evaluated using FTIR spectroscopy, differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and dissolution studies. Optimum ratio was utilized to assess lopinavir intestinal permeability. This employed in situ rabbit intestinal perfusion technique. FTIR, DSC and XRD indicated formation of lopinavir-menthol co-crystals at optimum molar ratio of 1:2. Additional menthol underwent phase separation due to possible self-association. Co-crystallization significantly enhanced lopinavir dissolution rate compared with pure drug to increase the dissolution efficiency from 24.96% in case of unprocessed lopinavir to 91.43% in optimum formulation. Lopinavir showed incomplete absorption from duodenum and jejuno-iliac segments with lower absorptive clearance from jejuno-ileum reflecting P-gp efflux. Co-perfusion with menthol increased lopinavir intestinal permeability. The study introduced menthol as co-crystal co-former for enhanced dissolution and augmented intestinal absorption of lopinavir.

Exploring the Predictive Power of the In Situ Perfusion Technique towards Drug Absorption: Theory, Practice, and Applications.

Considering the broad applications and popularity, the in situ perfusion technique is an established and interesting approach to evaluate the absorption mechanisms of drug molecules in specific regions of the intestinal tract. Compared to perfusion studies in humans, this surrogate model shows several familiar characteristics making it interesting to apply this technique in rats in the non-clinical stage of drug product development. The differences in gastrointestinal (GI) anatomy and physiology between rats and humans are thoroughly discussed in the present review. Moreover, an in-depth overview of the Doluisio (i.e., closed-loop) versus the single-pass intestinal perfusion (i.e., open-loop) technique is shown. Finally, applications and future perspectives of the technique are presented.

Influence of piperine and omeprazole on the regional absorption of Daclatasvir from rabbit intestine.

The study assessed the site dependent intestinal absorption of Daclatasvir and investigated the effects of piperine and omeprazole on such absorption utilizing in situ rabbit intestinal perfusion technique. The intestinal absorption of Daclatasvir was assessed in four segments: duodenum, jejunum, ileum, and colon. The effect of co-perfusion with omeprazole was monitored through the tested anatomical sites. The effect of piperine, a P-glycoprotein (P-gp) inhibitor on Daclatasvir absorption from jejunum and ileum was tested. The results showed that Daclatasvir was incompletely absorbed from the rabbit small and large intestine. The absorptive clearance per unit length (PeA/L) was site dependent and was ranked as colon>duodenum>jejunum>ileum. This rank is the opposite of the rank of P-gp intestinal content suggesting possible influence for P-gp. Co-perfusion with omeprazole increased PeA/L and this was evidenced also with reduced the L95% of Daclatasvir from both small and large intestinal segments. Significant enhancement in Daclatasvir absorption through jejunum and ileum was shown in presence of piperine. Daclatasvir showed site dependent intestinal absorption in a manner suggesting its affection by P-gp efflux. This effect was inhibited by piperine. Co-administration of Daclatasvir with omeprazole can enhance intestinal absorption a phenomenon which requires extension to human pharmacokinetic investigation.

Investigation of the effect of verapamil on the regional absorption of sofosbuvir from rabbit intestine in situ.

Sofosbuvir, a nucleotide antiviral drug, is a Biopharmaceutics Classification System (BCS) class III prodrug suffering from limited intestinal absorption due to its high hydrophilicity and low intestinal permeability. This research aims to investigate the luminal stability of Sofosbuvir, the influence of anatomical site on its intestinal absorption and the effects of verapamil on such absorption. The study utilized in situ rabbit intestinal perfusion technique to examine absorption of Sofosbuvir from duodenum, jejunum, ileum and ascending colon. This was conducted both with and without verapamil. The luminal stability study showed that Sofosbuvir was subjected to premature degradation with varying fractions degraded from the different intestinal segments. The in situ perfusion data showed incomplete absorption of Sofosbuvir from small and large intestinal segments. The recorded values of the absorptive clearance per unit length (Pe.A/L) of Sofosbuvir were 0.026, 0.0075, 0.0026, & 0.054ml/min.cm for duodenum, jejunum, ileum, and ascending colon, respectively. The Pe.A/L values were ordered as colon > duodenum > jejunum > ileum. This is the opposite rank of P-gp content in the different intestinal segments. The recorded values of the length required for complete Sofosbuvir absorption (L95%) were 29.58, 128.47, 949.2 and, 13.63cm for duodenum, jejunum, ileum, and ascending colon, respectively. Co-perfusion with verapamil significantly increased Pe.A/L and reduced the L95% of Sofosbuvir from both jejunum and ileum (P-value < 0.05). The results indicated that the absorptive clearance of Sofosbuvir was site dependent and associated with the content of P-glycoprotein, in addition to the expected drug interactions that can occur in polymedicated hepatitis C virus (HCV) infected patients.

Integration of In Silico, In Vitro and In Situ Tools for the Preformulation and Characterization of a Novel Cardio-Neuroprotective Compound during the Early Stages of Drug Development.

The main aim of this work is the biopharmaceutical characterization of a new hybrid benzodiazepine-dihydropyridine derivative, JM-20, derived with potent anti-ischemic and neuroprotective effects. In this study, the pKa and the pH-solubility profile were experimentally determined. Additionally, effective intestinal permeability was measured using three in vitro epithelial cell lines (MDCK, MDCK-MDR1 and Caco-2) and an in situ closed-loop intestinal perfusion technique. The results indicate that JM-20 is more soluble at acidic pH (9.18 ± 0.16); however, the Dose number (Do) was greater than 1, suggesting that it is a low-solubility compound. The permeability values obtained with in vitro cell lines as well as with the in situ perfusion method show that JM-20 is a highly permeable compound (Caco-2 value 3.8 × 10−5). The presence of an absorption carrier-mediated transport mechanism was also demonstrated, as well as the efflux effect of P-glycoprotein on the permeability values. Finally, JM-20 was provisionally classified as class 2 according to the biopharmaceutical classification system (BCS) due to its high intestinal permeability and low solubility. The potential good oral absorption of this compound could be limited by its solubility.

Cell-penetrating peptide-surface modified liposomes to enhance the intestinal absorption of enoxaparin

Enoxaparin is low-molecular-weight heparin administered by subcutaneous/intravenous injection. The oral bioavailability of enoxaparin is restricted by its low absorption through the intestine. In this study cell-penetrating peptide-surface functionalized liposomes (CPPs-L) were prepared to improve the intestinal absorption of enoxaparin. Liposomal formulations were prepared by the ethanol injection method and the intestinal absorption of the formulation was evaluated using single-pass intestinal perfusion (SPIP) technique in rats. Meanwhile, the human fraction dose absorbed value (Fa (human)) of the formulations were predicted based on the calculated effective intestinal permeability (P effect (rat)) values obtained from the SPIP study. Liposomal enoxaparin revealed an increased intestinal absorption by ten-time compared with the free drug solution. Meanwhile, CPPs-L formulation revealed an enhanced intestinal absorption compared with the un-modified liposomal formulation. Regarding Fa (human), it is predicted that liposomal formulations could have the potential to improve the fraction dose absorbed of enoxaparin from low to intermediate level. Overall, the liposomal formulation can be considered as a mighty drug carrier for the oral delivery of enoxaparin.

Reply to "Comment on López-Yerena et al. 'Absorption and Intestinal Metabolic Profile of Oleocanthal in Rats' Pharmaceutics 2020, 12, 134".

Recently, in February 2020, we published a study exploring the intestinal absorption and metabolism of oleocanthal (OLC) in rats. A single-pass intestinal perfusion technique (SPIP) was used, involving simultaneous sampling from the luminal perfusate and mesenteric blood. Later, comments on our published paper were released, requesting clarification of specific data. In this detailed reply, we hope to have addressed and clarified all the concerns of A. Kaddoumi and K. El Sayed and that the scientific community will benefit from both the study and the comments it has generated.

Enhancement of the intestinal absorption of bortezomib by self-nanoemulsifying drug delivery system

Purpose: Intestinal drug absorption is one of the main factors that govern the fraction of oral dose absorbed (Fa) of drugs. It is reported that oral absorption of bortezomib (BTZ) can be restricted by its low intestinal permeability. In this study, we aimed to evaluate the impact of self-nanoemulsifying drug delivery systems (SNEDDS) on the intestinal absorption and Fa of BTZ.Methods: Intestinal permeability studies were conducted using in situ single-pass intestinal perfusion (SPIP) technique in rats. Human intestinal absorption (Peff (Human)) and Fa values of BTZ and BTZ-SNEDDS were predicted based on SPIP data.Results: Based on the obtained data, Peff (rat) values of (3.36 ± 0.5) × 10−5 and (8.9 ± 3) × 10−5 cm/s (mean ± SEM) were calculated for BTZ and BTZ-SNEDDS, respectively. Meanwhile, Peff (human) values of (7 × 10−5) and (68 × 10−5) cm/sec were predicted for BTZ and BTZ-SNEDDS, respectively. Besides, Fa (human) values of 72.5 and 97% were estimated for BTZ and BTZ-SNEDDS, respectively.Conclusions: According to the obtained data, it is concluded that SNEDDS can be considered as a promising drug delivery system to improve the intestinal absorption and Fa values of BTZ.

Possible Role of P-Glycoprotein in Cyclosporine -Acitretin Drug Interaction

P-glycoprotein, an efflux transporter prevents intracellular accumulation of xenobiotics. Cyclosporine A and acitretin are used to treat psoriasis. The present research work aims to investigate the possible role of P-glycoprotein in Cyclosporine- Acitretin drug interaction due to evidence of both drugs having affinity for P-glycoprotein.The study has three different objective namely to assess apparent permeability coefficient of cyclosporine in presence of acitretin by non-everted sac technique, to study the intestinal permeation and absorption kinetics of cyclosporine in presence of acitretin by single pass intestinal perfusion (SPIP) technique and to study the influence of acitretin on oral bioavailability of cyclosporine in Wistar rats.The result of ex vivo, in situ and in vivo study showed that cyclosporine level increased in a time dependent manner. As the dose of acitretin increases the cyclosporine concentration in all three methods tend to increase and was statistically significant. The improvement in absorption of cyclosporine may be due to the inhibition of P-glycoprotein transporter in the intestine by acitretin. Thus acitretin may enhance the oral pharmacokinetics of cyclosporine. Hence this combination may require close monitoring for better therapeutic outcome. Our study confirmed the inhibitory role of acitretin on P-glycoprotein leading to increase concentration of cyclosporine.

Applicability analysis and evaluation of aglycones in single-pass intestinal perfusion technique based on PBPK model

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.

INFLUENCE OF P-GLYCOPROTEIN AND CYTOCHROME ISOENZYME-P3A4 ON BIOAVAILABILITY OF ANTICANCER DRUGS WITH CURCUMIN BY IN SITU INTESTINAL PERFUSION IN MALE WISTAR RATS

Objectives: An orally administered anticancer drug has been poor drug absorption; drug resistance and metabolism, which alters the bioavailability of drugs. An in situ intestine perfusion technique is developing under the different perfusion rates in the presence of drug inducers and inhibitors of cytochrome isoenzyme-P (CYP)-3A4 and P-glycoprotein (P-gp) for drug concentrations.&#x0D; Materials and Methods: The modified in situ intestinal perfusion technique was developed and followed to obtain the portal and hepatic venous blood samples paralleled at different perfusion time and flow rates of 0.05, 0.1, 0.5, and 1.0 mL/min using the imatinib (1 mg/mL) drug alone and in the presence of drug inducer and drug inhibitor for the period of 3 h. The imatinib drug concentrations were assayed using high-pressure liquid chromatography.&#x0D; Results: The results reveal that the mean imatinib drug concentrations in portal vein were higher than hepatic vein at various perfusion flow rates and time intervals were observed. The area under curve and plasma drug concentrations maximum of imatinib alone absorptions were significantly different between portal and hepatic veins (p&lt;0.05) at the flow rates of 0.5 and 1.0 mL/min and also in the presence of drug inducer and inhibitors that indicating for the considerable hepatic involvement in the presystemic extraction or metabolism of drugs.&#x0D; Conclusions: The in situ perfusions approach could provide the useful tool for improving the basic understanding of absorption kinetics and hepatic metabolism of drugs in the presence of drug inducers and drug inhibitors (CYP3A4 and P-gp) under the development and facilitating the clinical applications.

Investigating Intestinal Permeability of Bortezomib Using a Validated HPLC-UV Method.

Bortezomib (BTZ), as a proteasome inhibitor, has been used for treatment of patients with relapsed/refractory multiple myeloma and mantle cell lymphoma. BTZ is available for intravenous injection or subcutaneous administration. In this study, for evaluating the potential of BTZ oral delivery, intestinal permeability of BTZ was determined using in situ single-pass intestinal perfusion (SPIP) technique and the perfused solutions were analyzed using a validated HPLC-UV method. The chromatographic separation was performed using a C18 column via isocratic mode at a flow rate of 0.5 mL/min at 270 nm. The mobile phase was a mixture of methanol/deionized water (50:50% v/v) with 0.1% glacial acetic acid. The results indicated that calibration curves were linear (r2 ˃0.99) in a concentration range of 1.65-5 µg/mL for BTZ and 8.33-25 µg/mL for phenol red. A limit of quantitation of 1.03 and 6.67 µg/mL was obtained for BTZ and phenol red, respectively. The recovery values were in the range of 96.5-105.4% for BTZ, and 88-99.2% for phenol red. The relative standard deviations (RSD) were ≤4.9% for BTZ and ≤7% for phenol red. Stability studies indicated that the working standard solution is stable over a period of 48 h at room temperature. Finally, an effective permeability (Peff) value of (3.36±0.5)×10-5 cm/sec (mean±SEM) was achieved for BTZ. Moreover, it was predicted that BTZ belongs to the biopharmaceutical class ІІІ.

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.