Enhancing effect of Labrasol on the intestinal absorption of ganciclovir in rats

Enhancement of Curcumin's Anti-Psoriatic Efficacy via Formulation into Tea Tree Oil-Based Emulgel

Psoriasis is a chronic inflammatory skin disease characterized by the hyperproliferation and aberrant differentiation of epidermal keratinocytes. It is a debilitating condition that can cause significant physical and emotional distress. Natural anti-psoriatic agents have been investigated as alternatives to conventional allopathic medications, as they have notable limitations and drawbacks. Curcumin and tea tree oil are cost-efficient and effective anti-inflammatory medicines with less adverse effects compared to synthetic psoriasis medications. Our research endeavors to harness the therapeutic potential of these natural compounds by developing an herbal anti-psoriatic topical drug delivery system. This novel method uses curcumin and tea tree oil to create a bi-phasic emulgel drug delivery system. Formulations F1 (gel) and F2 (emulgel) have high drug content percentages of 84.2% and 96.7%, respectively. The emulgel showed better spreadability for cutaneous applications, with a viscosity of 92,200 ± 943 cp compared to the gel's 56,200 ± 1725 cp. The emulgel released 94.48% of the drugs, compared to 87.58% for the gel. These formulations conform to the zero-order and Higuchi models, and their stability over a three-month period is crucial. In vivo, the emulgel healed psoriasis symptoms faster than the usual gel. The gathered results confirmed the emulgel's potential as a drug delivery method, emphasizing the complementary benefits of tea tree oil and curcumin as an effective new therapy for psoriasis.

Nanostructured Lipid Carrier-Based Codelivery of Raloxifene and Naringin: Formulation, Optimization, In Vitro, Ex Vivo, In Vivo Assessment, and Acute Toxicity Studies

This work aimed to develop dual drug-loaded nanostructured lipid carriers of raloxifene and naringin (RLX/NRG NLCs) for breast cancer. RLX/NRG NLCs were prepared using Compritol 888 ATO and oleic acid using a hot homogenization-sonication method and optimized using central composite design (CCD). The optimized RLX/NRG NLCs were characterized and evaluated using multiple technological means. The optimized RLX/NRG NLCs exhibited a particle size of 137.12 nm, polydispersity index (PDI) of 0.266, zeta potential (ZP) of 25.9 mV, and entrapment efficiency (EE) of 91.05% (raloxifene) and 85.07% (naringin), respectively. In vitro release (81 ± 2.2% from RLX/NRG NLCs and 31 ± 1.9% from the RLX/NRG suspension for RLX and 93 ± 1.5% from RLX/NRG NLCs and 38 ± 2.01% from the RLX/NRG suspension for NRG within 24 h). Concurrently, an ex vivo permeation study exhibited nearly 2.3 and 2.1-fold improvement in the permeability profiles of RLX and NRG from RLX/NRG NLCs vis-à-vis the RLX/NRG suspension. The depth of permeation was proved with CLSM images which revealed significant permeation of the drug from the RLX/NRG NLCs formulation, 3.5-fold across the intestine, as compared with the RLX/NRG suspension. An in vitro DPPH antioxidant study displayed a better antioxidant potential of RLX/NRG in comparison to RLX and NRG alone due to the synergistic antioxidant effect of RLX and NRG. An acute toxicity study in Wistar rats showed the safety profile of the prepared nanoformulations and their excipients. Our findings shed new light on how poorly soluble and poorly permeable medicines can be codelivered using NLCs in an oral nanoformulation to improve their medicinal performance.

Interaction of Commonly Used Oral Molecular Excipients with P-glycoprotein

P-glycoprotein (P-gp) plays a critical role in drug oral bioavailability, and modulation of this transporter can alter the safety and/or efficacy profile of substrate drugs. Individual oral molecular excipients that inhibit P-gp function have been considered a mechanism for improving drug absorption, but a systematic evaluation of the interaction of excipients with P-gp is critical for informed selection of optimal formulations of proprietary and generic drug products. A library of 123 oral molecular excipients was screened for their ability to inhibit P-gp in two orthogonal cell-based assays. β-Cyclodextrin and light green SF yellowish were identified as modest inhibitors of P-gp with IC₅₀ values of 168 μM (95% CI, 118-251 μM) and 204 μM (95% CI, 5.9-1745 μM), respectively. The lack of effect of most of the tested excipients on P-gp transport provides a wide selection of excipients for inclusion in oral formulations with minimal risk of influencing the oral bioavailability of P-gp substrates.

Oral delivery of peptide therapeutics in infants: Challenges and opportunities

The vast majority of drugs are not designed or developed for pediatric and infant populations. Peptide drugs, which have become increasingly relevant in the past several decades, are no exception. Unfortunately, nearly all of the 60+ approved peptide drugs are formulated for injection, a particularly unfriendly mode of administration for infants. Although three peptide drugs were recently approved for oral formulations, this major advance in peptide drug delivery is available only for adults. In this review, we consider the current challenges and opportunities for the oral formulation of peptide therapeutics, specifically for infant populations. We describe the strategies that enable oral protein delivery and the potential impact of infant physiology on those strategies. We also detail the limited but encouraging progress towards 1) adapting conventional drug development and delivery approaches to infants and 2) designing novel infant-centric formulations. Together, these efforts underscore the feasibility of oral peptide delivery in infants and provide motivation to increase attention paid to this underserved area of drug delivery and formulation.

Enhanced Oral Bioavailability and Improved Biological Activities of a Quercetin/Resveratrol Combination Using a Liquid Self-Microemulsifying Drug Delivery System

Both quercetin and resveratrol are promising plant-derived compounds with various well-described biological activities; however, they are categorized as having low aqueous solubility and labile natural compounds. The purpose of the present study was to propose a drug delivery system to enhance the oral bioavailability of combined quercetin and resveratrol. The suitable self-microemulsifying formulation containing quercetin together with resveratrol comprised 100 mg Capryol 90, 700 mg Cremophor EL, 200 mg Labrasol, 20 mg quercetin, and 20 mg resveratrol, which gave a particle size of 16.91 ± 0.08 nm and was stable under both intermediate and accelerated storage conditions for 12 months. The percentages of release for quercetin and resveratrol in the self-microemulsifying formulation were 75.88 ± 1.44 and 86.32 ± 2.32%, respectively, at 30 min. In rats, an in vivo pharmacokinetics study revealed that the area under the curve of the self-microemulsifying formulation containing quercetin and resveratrol increased approximately ninefold for quercetin and threefold for resveratrol compared with the unformulated compounds. Moreover, the self-microemulsifying formulation containing quercetin and resveratrol slightly enhanced the in vitro antioxidant and cytotoxic effects on AGS, Caco-2, and HT-29 cells. These findings demonstrate that the self-microemulsifying formulation containing quercetin and resveratrol could successfully enhance the oral bioavailability of the combination of quercetin and resveratrol without interfering with their biological activities. These results provide valuable information for more in-depth research into the utilization of combined quercetin and resveratrol.

Tailoring functional nanostructured lipid carriers for glioblastoma treatment with enhanced permeability through in-vitro 3D BBB/BBTB models

The blood-brain barrier (BBB) and blood-brain tumour barrier (BBTB) pose a significant challenge to drug delivery to brain tumours, including aggressive glioblastoma (GB). The present study rationally designed functional nanostructured lipid carriers (NLC) to tailor their BBB penetrating properties with high encapsulation of CNS negative chemotherapeutic drug docetaxel (DTX). We investigated the effect of four liquid lipids, propylene glycol monolaurate (Lauroglycol® 90), Capryol® propylene glycol monocaprylate, caprylocaproylmacrogol-8-glycerides (Labrasol®) and polyoxyl-15-hydroxystearate (Kolliphor® HS15) individually and in combination to develop NLCs with effective permeation across in-vitro 3D BBB model without alteration in the integrity of the barrier. With desirable spherical shape as revealed by TEM and an average particle size of 123.3 ± 0.642 nm and zeta potential of -32 mV, DTX-NLCs demonstrated excellent stability for six months in its freeze-dried form. The confocal microscopy along with flow cytometry data revealed higher internalisation of DTX-NLCs in U87MG over SVG P12 cells. Micropinocytosis was observed to be one of the dominant pathways for internalisation in U87MG cells while clathrin-mediated pathway was more predominat in patient-derived glioblastoma cells. The NLCs readily penetrated the actively proliferating peripheral cells on the surface of the 3D tumour spheroids as compared to the necrotic core. The DTX-NLCs induced cell arrest through G2/M phase with a significant decrease in the mitochondrial reserve capacity of cells. The NLCs circumvented BBTB with high permeability followed by accumulation in glioblastoma cells with patient-derived cells displaying ~2.4-fold higher uptake in comparison to U87MG when studied in a 3D in-vitro model of BBTB/GB. We envisage this simple and industrially feasible technology as a potential candidate to be developed as GB nanomedicine.

Abdulbaqi I, Seok Ming T, Siok Yee C, A. Wahab H, Asif SM, Darwis Y. Liquid and Solid Self-Emulsifying Drug Delivery Systems (SEDDs) as Carriers for the Oral Delivery of Azithromycin: Optimization, In Vitro Characterization and Stability Assessment

Azithromycin (AZM) is a macrolide antibiotic used for the treatment of various bacterial infections. The drug is known to have low oral bioavailability (37%) which may be attributed to its relatively high molecular weight, low solubility, dissolution rate, and incomplete intestinal absorption. To overcome these drawbacks, liquid (L) and solid (S) self-emulsifying drug delivery systems (SEDDs) of AZM were developed and optimized. Eight different pseudo-ternary diagrams were constructed based on the drug solubility and the emulsification studies in various SEDDs excipients at different surfactant to co-surfactant (Smix) ratios. Droplet size (DS) < 150 nm, dispersity (Đ) ≤ 0.7, and transmittance (T)% > 85 in three diluents of distilled water (DW), 0.1 mM HCl, and simulated intestinal fluids (SIF) were considered as the selection criteria. The final formulations of L-SEDDs (L-F1(H)), and S-SEDDs (S-F1(H)) were able to meet the selection requirements. Both formulations were proven to be cytocompatible and able to open up the cellular epithelial tight junctions (TJ). The drug dissolution studies showed that after 5 min > 90% and 52.22% of the AZM was released from liquid and solid SEDDs formulations in DW, respectively, compared to 11.27% of the pure AZM, suggesting the developed SEDDs may enhance the oral delivery of the drug. The formulations were stable at refrigerator storage conditions.

Anti-Angiogenic Effect of Orally Available Pemetrexed for Metronomic Chemotherapy

Metronomic chemotherapy (MCT) is defined as the frequent administration of low-dose chemotherapeutics, without long drug-free periods, with the exertion of antitumor activity exclusively through anti-angiogenic mechanisms. In this study, we have developed an orally available formulation of pemetrexed (PMX) for MCT. PMX was first complexed ionically with N^α-deoxycholyl-l-lysyl-methylester (DCK) as the permeation enhancer. This was followed by dispersion with poloxamer 188 and Labrasol to form the solid oral formulation of PMX (PMX/DCK-OP). PMX/DCK-OP exhibited a 10.6-fold increase in permeability across a Caco-2 cell monolayer compared to PMX alone. This resulted in a 70-fold increase in the oral bioavailability of PMX/DCK-OP in mice over oral PMX alone. In the A549 xenograft model, tumor volume was reduced by 51.1% in the PMX/DCK-OP treated group compared to only 32.8% in the maximum tolerated dose (MTD)-treated group. Furthermore, PMX/DCK-OP exhibited a significant anti-angiogenic effect on the A549 xenograft mice when compared to the MTD-treated group, as indicated by microvessel density quantification for CD-31. In addition, PMX/DCK-OP enhanced the release of an endogenous angiogenesis inhibitor, thrombospondin-1 (TSP-1), into both the blood circulation and the tumor microenvironment. Therefore, due to its oral route of administration, PMX/DCK-OP appears to be a better alternative to the conventional treatment of PMX.

Solidified SNEDDS for the oral delivery of rifampicin: Evaluation, proof of concept, in vivo kinetics, and in silico GastroPlusTM simulation

The present investigation was performed to develop a rifampicin (RIF)-loaded solidified self-nanoemulsifying drug delivery system (SNEDDS) (solidified RIF-OF1) for in vitro and in vivo evaluations. Optimized formulations were tested for their powder flow characteristics, loading efficiency, and in vitro dissolution (at pH-1.2, 6.8 and 7.4). Compatibility studies were also performed. The formulations were also tested for hemocompatibility, intestinal permeation, histopathological effects, and in vivo pharmacokinetics. Additionally, an in silico simulation study using GastroPlus was performed. At different varied pH values, we observed immediate release (T_85% within 15 min) based on the dissolution profile. This could be due to labrasol-assisted RIF solubilization. In vitro hemolysis study of the reconstituted RIF-OF1 revealed normal architecture of erythrocytes compared to the positive control (lysed and fragmented). Through in vivo permeation and biopsy studies, a rationale for facilitated intestinal permeation of RIF with components deemed physiological safe (normal anatomy of mucosal membrane evidenced from biopsy study) could be established. The in vitro-in vivo correlation (IVIVC) plus module of GastroPlus^TM simulation showed a good IVIVC between in vitro release and in vivo absorption with a predicted systemic absorption of ∼96.5%. Solidified SNEDDS showed improved pharmacokinetic profiles compared to RIF suspension. Solid RIF-SNEDDS was demonstrated to be a suitable carrier for enhanced intestinal permeation and oral bioavailability. Hence, it may serve as a suitable alternative to conventional delivery systems for tuberculosis treatment.

Gintonin absorption in intestinal model systems

Background

Recently, we identified a novel ginseng-derived lysophosphatidic acid receptor ligand, called gintonin. We showed that gintonin induces [Ca²⁺]i transient-mediated morphological changes, proliferation, and migration in cells expressing lysophosphatidic acid receptors and that oral administration of gintonin exhibits anti-Alzheimer disease effects in model mice. However, little is known about the intestinal absorption of gintonin. The aim of this study was to investigate gintonin absorption using two model systems.

Methods

Gintonin membrane permeation was examined using a parallel artificial membrane permeation assay, and gintonin absorption was evaluated in a mouse everted intestinal sac model.

Results

The parallel artificial membrane permeation assay showed that gintonin could permeate an artificial membrane in a dose-dependent manner. In the everted sac model, gintonin absorption increased with incubation time (from 0 min to 60 min), followed by a decrease in absorption. Gintonin absorption into everted sacs was also dose dependent, with a nonlinear correlation between gintonin absorption and concentration at 0.1–3 mg/mL and saturation at 3–5 mg/mL. Gintonin absorption was inhibited by the Rho kinase inhibitor Y-27632 and the sodium–glucose transporter inhibitor phloridzin. Moreover, lipid extraction with methanol also attenuated gintonin absorption, suggesting the importance of the lipid portion of gintonin in absorption. This result shows that gintonin might be absorbed through passive diffusion, paracellular, and active transport pathways.

Conclusion

The present study shows that gintonin could be absorbed in the intestine through transcellular and paracellular diffusion, and active transport. In addition, the lipid component of gintonin might play a key role in its intestinal absorption.

Experimental design-based optimization of lipid nanocarrier as delivery system against Mycobacterium species: in vitro and in vivo evaluation

The study aimed to optimize self-nanoemulsifying drug delivery system using experimental design using excipients holding innate anti-mycobacterium activities followed with characterizations for responses such as optical clarity (Y₁), zone of inhibition (ZOI) against Mycobacterium smegmatis strains (Y₂, Y₃), and globular size (Y₄). The optimized formulations (OF1-OF3) were further characterized for responses and evaluated for zeta potential, minimum inhibition concentration (MIC) against non-pathogenic and tubercular strains, morphological (electron microscopy and atomic force microscopy), and confocal laser scanning microscopy (CLSM) studies. The desirability analysis suggested that the predicted values of the OF1 for the responses Y₁, Y₂, Y₃, and Y₄ were 0.137, 22.77 mm, 21.9 mm, and 191.11 nm, respectively. The morphological assessment confirmed the in vitro studies and established the inhibition mechanism as evidenced with oozing, ablation, and cell-wall fragmentation followed with cell disruption. The OF1, OF2, and OF3 showed an MIC value at 8.8 ± 0.56 mg/ml, 12.5 ± 0.22 mg/ml, and 15.0 ± 0.4 mg/ml, respectively, corroborating effectiveness against tubercular strain. CLSM studies revealed 75.1, 80.3, and 88.7% as an intense fluorescence intensity of OF1, OF2, and OF3, respectively, as compared with dye solution (∼53%). Conclusively, it can be inferred that the delivery of anti-tubercular drugs might be reassessed using excipients with inherent anti-mycobacterium activities.

In vitro–in vivo–in silico simulation studies of anti-tubercular drugs doped with a self nanoemulsifying drug delivery system

This study aimed to formulate a self-nanoemulsifying drug delivery system (SNEDDS) for enhanced pharmacokinetic (PK) behavior of rifampicin and isoniazid using excipients holding innate anti-mycobacterial activity followed within vivo–in silicopredictions using GastroPlus™.

Evidences for anti-mycobacterium activities of lipids and surfactants

Tuberculosis is the most widespread and deadly airborne disease caused by Mycobacterium tuberculosis. The two-pronged lethal effect on the bacteria using lipids/surfactants and anti-tubercular drugs may render the miniaturization of dose owing to synergistic and tandem effect of both. The current research has been focused on screening and evaluating various lipids/surfactants possessing inherent anti-mycobacterium activity that can ferry the anti-tubercular drugs. In vitro anti-mycobacterium activity was evaluated using agar well diffusion method. Furthermore, time-concentration dependent killing and DNA/RNA content release studies were performed to correlate the findings. The exact mechanism of bacterial killing was further elucidated by electron/atomic force microscopy studies. Finally, to negate any toxicity, in vitro hemolysis and toxicity studies were performed. The study revealed that capmul MCM C-8, labrasol and acconon C-80 possessed highest in vitro anti-mycobacterium activity. Electron/atomic force microscopy results confirmed in vitro studies and verified the killing of Mycobacterium owing to the release of cytoplasmic content after cell wall fragmentation and disruption. Moreover, the least hemolysis and hundred percent survivals rate of mice using the excipients demonstrated the safety aspects of explored excipients that can ferry the anti-tubercular drugs. The present study concluded the safe, efficient and synergistic activity of the explored excipients and anti-tubercular drugs in controlling the menace of tuberculosis.

Self-micro emulsifying formulation improved intestinal absorption and oral bioavailability of bakuchiol

Bakuchiol (BAK), isolated from the seeds of Psoralea corylifolia L., recently presents a variety of pharmacologic activities. However, the poor oral bioavailability limits its further development and clinical use. The purpose of this study was to establish a self-microemulsifying (SME) formulation for oral delivery improvement of BAK. The optimized liquid SME formulation was comprised of BAK (40 %), Cremophor RH 40 (30 %) and Labrasol (30 %). The emulsion droplets were spherical in shape, and particle size and zeta potential were determined. The in vitro dissolution test of BAK-SME formulation illustrated faster dissolution rate than the bulk drug. The permeabilities of 40 μg mL-1 BAK-SME formulation in rat intestinal segments of duodenum, jejunum, ileum and colon were 30.91 × 10-3, 23.61 × 10-3, 29.43 × 10-3 and 23.62 × 10-3 cm min-1, respectively, exhibiting 3.99 times in duodenum, 2.59 times in ileum and 2.31 times in colon greater than BAK perfusate. The oral bioavailability of BAK-SME formulation at a dose of 150 mg kg-1 was determined in rats. The Cmax and the AUC(0-24h) were 515.4 ng mL-1 and 4,327.2 h ng mL-1, respectively, which were 1.90 fold and 1.73 fold greater than the value of BAK suspension. All these results clearly stated that BAK-SME formulation performed well-improvement on oral bioavailability of BAK.

Artemisia dracunculus L. polyphenols complexed to soy protein show enhanced bioavailability and hypoglycemic activity in C57BL/6 mice

OBJECTIVE

Scientifically validated food-based interventions are a practical means of addressing the epidemic of metabolic syndrome. An ethanolic extract of Artemisia dracunculus L. (PMI-5011) containing bioactive polyphenols, such as 2', 4'-dihydroxy-4-methoxydihydrochalcone (DMC-2), improved insulin resistance in vitro and in vivo. Plant polyphenols are concentrated and stabilized when complexed to protein-rich matrices, such as soy protein isolate (SPI), which act as effective food-based delivery vehicles. The aim of this study was to compare the bioaccessibility, bioavailability, and efficacy of polyphenols extracted from A. dracunculus and delivered as PMI-5011 (ethanolic extract alone), formulated with the non-food excipient Gelucire(®), (5011- Gelucire), or sorbed to SPI (5011-Nutrasorb(®)).

METHODS

PMI-5011, 5011-Gelucire or 5011-Nutrasorb each containing 162 μg of DMC-2 was delivered to the TNO intestinal model-1 of the human upper gastrointestinal tract to compare the effect of delivery vehicle on DMC-2 bioaccessibility. C57BL6/J mice were orally administered 5011-Nutrasorb or PMI-5011 to compare effects of polyphenol-protein complexation on acute hypoglycemic activity and bioavailability of DMC-2 in serum.

RESULTS

At 500 mg/kg, 5011-Nutrasorb and PMI-5011 had similar hypoglycemic activity in a high-fat diet-induced diabetes mouse model despite the fact that 5011-Nutrasorb delivered 15 times less DMC-2 (40 versus 600 μg/kg). This can be partially explained by eight times greater DMC-2 absorption into serum from 5011-Nutrasorb than from PMI-5011. TNO intestinal model-1 experiments confirmed higher total bioaccessibility of DMC-2 in vitro when delivered in 5011-Nutrasorb (50.2%) or Gelucire-5011 (44.4%) compared with PMI-5011 (27.1%; P = 0.08).

CONCLUSION

Complexation with soy protein makes antidiabetic A. dracunculus polyphenols more bioavailable and bioaccessible.