Novel in vitro transport method for screening the reversibility of P-glycoprotein inhibitors

Self-Nanoemulsion Intrigues the Gold Phytopharmaceutical Chrysin: In Vitro Assessment and Intrinsic Analgesic Effect

Chrysin is a natural flavonoid with a wide range of bioactivities. Only a few investigations have assessed the analgesic activity of chrysin. The lipophilicity of chrysin reduces its aqueous solubility and bioavailability. Hence, self-nanoemulsifying drug delivery systems (SNEDDS) were designed to overcome this problem. Kollisolv GTA, Tween 80, and Transcutol HP were selected as oil, surfactant, and cosurfactant, respectively. SNEDDS A, B, and C were prepared, loaded with chrysin (0.1%w/w), and extensively evaluated. The optimized formula (B) encompasses 25% Kollisolv GTA, 18.75% Tween 80, and 56.25% Transcutol HP was further assessed. TEM, in vitro release, and biocompatibility towards the normal oral epithelial cell line (OEC) were estimated. Brain targeting and acetic acid-induced writhing in a mouse model were studied. After testing several adsorbents, powdered SNEDDS B was formulated and evaluated. The surfactant/cosurfactant (S/CoS) ratio of 1:3 w/w was appropriate for the preparation of SNEDDS. Formula B exhibited instant self-emulsification, spherical nanoscaled droplets of 155.4 ± 32.02 nm, and a zeta potential of - 12.5 ± 3.40 mV. The in vitro release proved the superiority of formula B over chrysin suspension (56.16 ± 10.23 and 9.26 ± 1.67%, respectively). The biocompatibility of formula B towards OEC was duplicated (5.69 ± 0.03 µg/mL). The nociceptive pain was mitigated by formula B more efficiently than chrysin suspension as the writhing numbers reduced from 8.33 ± 0.96 to 0 after 60 min of oral administration. Aerosil R972 was selected as an adsorbent, and its chemical compatibility was confirmed. In conclusion, our findings prove the therapeutic efficacy of chrysin self-nanoemulsion as a potential targeting platform to combat pain.

Influence of a Short Course of Ritonavir Used as Booster in Antiviral Therapies Against SARS-CoV-2 on the Exposure of Atorvastatin and Rosuvastatin

PURPOSE

Early antiviral treatment with nirmatrelvir/ritonavir is recommended for SARS-CoV-2-infected patients at high risk for severe courses. Such patients are usually chronically ill and susceptible to adverse drug interactions caused by ritonavir. We investigated the interactions of short-term low-dose ritonavir therapy with atorvastatin and rosuvastatin, two statins commonly used in this population.

METHOD

We assessed exposure changes (area under the concentration-time curve (AUC∞) and maximum concentration (Cmax)) of a single dose of 10 mg atorvastatin and 10 mg rosuvastatin before and on the fifth day of ritonavir treatment (2 × 100 mg/day) in healthy volunteers and developed a semi-mechanistic pharmacokinetic model to estimate dose adjustment of atorvastatin during ritonavir treatment.

RESULTS

By the fifth day of ritonavir treatment, the AUC∞ of atorvastatin increased 4.76-fold and Cmax 3.78-fold, and concurrently, the concentration of atorvastatin metabolites decreased to values below the lower limit of quantification. Pharmacokinetic modelling indicated that a stepwise reduction in atorvastatin dose during ritonavir treatment with a stepwise increase up to 4 days after ritonavir discontinuation can keep atorvastatin exposure within safe and effective margins. Rosuvastatin pharmacokinetics were only mildly modified; ritonavir significantly increased the Cmax 1.94-fold, while AUC∞ was unchanged.

CONCLUSION

Atorvastatin doses should likely be adjusted during nirmatrelvir/ritonavir treatment. For patients on a 20-mg dose, we recommend half of the original dose. In patients taking 40 mg or more, a quarter of the dose should be taken until 2 days after discontinuation of nirmatrelvir/ritonavir. Patients receiving rosuvastatin do not need to change their treatment regimen.

TRIAL REGISTRATION

EudraCT number: 2021-006634-39. DRKS00027838.

Inside-out extracellular vesicles-like biomimetic magnetic nanoparticles for efficient screening P-Glycoprotein inhibitors to overcome cancer multidrug resistance

The discovery of P-Glycoprotein (P-gp) inhibitors to block chemotherapy drugs efflux is considered an attractive treatment strategy for overcoming cancer multidrug resistance (MDR). Cell membrane biomimetic platform has emerged as a promising candidate method for screening small molecule P-gp inhibitors from natural products. However, randomly oriented cell membrane coating does not guarantee the inward-opening conformation of P-gp, limiting the precise screening of P-gp inhibitors. Herein, inside-out orientation extracellular vesicles camouflaged magnetic nanoparticles (IOVMNPs) were prepared to discover P-gp inhibitors with low toxicity and high efficiency from natural products. The orientation of extracellular vesicles on the surface of IOVMNPs was rigorously confirmed by immunogold electron microscopy and sialic acid quantification assay. Finally, two potential P-gp inhibitors, honokiol and magnolol, were captured by obtained IOVMNPs. The effect of MDR reversal in combination with chemotherapy drugs was further verified by pharmacological activity experiments. The inside-out orientation extracellular vesicles encapsulation strategy provides an effective tool for the discovery of novel P-gp inhibitors from nature products, thus further extending the application field of orientation assembly cell membrane biomimetic magnetic nanoparticles. This inside-out extracellular vesicles coating also proposes a new concept for the assembly of cell membrane biomimetic platform.

Lipid-based solubilization technology via hot melt extrusion: promises and challenges

INTRODUCTION

Self-emulsifying drug delivery systems (SEDDS) are a promising strategy to improve the oral bioavailability of poorly water-soluble drugs (PWSD). The excipients of SEDDS enable permeation through the mucus and gastro-intestinal barrier, inhibiting efflux transporters (e.g. P-glycoprotein) of drugs. Poor drug loading capacity and formulation instability are the main setbacks of traditional SEDDS. The use of polymeric precipitation inhibitors was shown to create supersaturable SEDDS with increased drug payload, and their solidification can help to overcome the instability challenge. As an alternative to several existing SEDDS solidification technologies, hot melt extrusion (HME) holds the potential for lean and continuous manufacturing of supersaturable solid-SEDDS. Despite being ubiquitously applied in solid lipid and polymeric processing, HME has not yet been widely considered for the preparation of SEDDS.

AREAS COVERED

The review begins with the rationale why SEDDS as the preferred lipid-based delivery systems (LBDS) is suitable for the oral delivery of PWSD and discusses the common barriers to oral administration. The potential of LBDS to surmount them is discussed. SEDDS as the flagship of LBDS for PWSD is proposed with a special emphasis on solid-SEDDS. Finally, the opportunities and challenges of HME from the lipid-based excipient (LBE) processing and product performance standpoint are highlighted.

EXPERT OPINION

HME can be a continuous, solvent-free, cost-effective, and scalable technology for manufacturing solid supersaturable SEDDS. Several critical formulations and process parameters in successfully preparing SEDDS via HME are identified.

DHW-221, a Dual PI3K/mTOR Inhibitor, Overcomes Multidrug Resistance by Targeting P-Glycoprotein (P-gp/ABCB1) and Akt-Mediated FOXO3a Nuclear Translocation in Non-small Cell Lung Cancer

Multidrug resistance (MDR) is considered as a primary hindrance for paclitaxel failure in non-small cell lung cancer (NSCLC) patients, in which P-glycoprotein (P-gp) is overexpressed and the PI3K/Akt signaling pathway is dysregulated. Previously, we designed and synthesized DHW-221, a dual PI3K/mTOR inhibitor, which exerts a remarkable antitumor potency in NSCLC cells, but its effects and underlying mechanisms in resistant NSCLC cells remain unknown. Here, we reported for the first time that DHW-221 had favorable antiproliferative activity and suppressed cell migration and invasion in A549/Taxol cells in vitro and in vivo. Importantly, DHW-221 acted as a P-gp inhibitor via binding to P-gp, which resulted in decreased P-gp expression and function. A mechanistic study revealed that the DHW-221-induced FOXO3a nuclear translocation via Akt inhibition was involved in mitochondrial apoptosis and G0/G1 cell cycle arrest only in A549/Taxol cells and not in A549 cells. Interestingly, we observed that high-concentration DHW-221 reinforced the pro-paraptotic effect via stimulating endoplasmic reticulum (ER) stress and the mitogen-activated protein kinase (MAPK) pathway. Additionally, intragastrically administrated DHW-221 generated superior potency without obvious toxicity via FOXO3a nuclear translocation in an orthotopic A549/Taxol tumor mouse model. In conclusion, these results demonstrated that DHW-221, as a novel P-gp inhibitor, represents a prospective therapeutic candidate to overcome MDR in Taxol-resistant NSCLC treatment.

Thiolated Nanoparticles for Biomedical Applications: Mimicking the Workhorses of Our Body

Advances in nanotechnology have generated a broad range of nanoparticles (NPs) for numerous biomedical applications. Among the various properties of NPs are functionalities being related to thiol substructures. Numerous biological processes that are mediated by cysteine or cystine subunits of proteins representing the workhorses of the bodies can be transferred to NPs. This review focuses on the interface between thiol chemistry and NPs. Pros and cons of different techniques for thiolation of NPs are discussed. Furthermore, the various functionalities gained by thiolation are highlighted. These include overall bio- and mucoadhesive, cellular uptake enhancing, and permeation enhancing properties. Drugs being either covalently attached to thiolated NPs via disulfide bonds or being entrapped in thiolated polymeric NPs that are stabilized via inter- and intrachain crosslinking can be released at the diseased tissue or in target cells under reducing conditions. Moreover, drugs, targeting ligands, biological analytes, and enzymes bearing thiol substructures can be immobilized on noble metal NPs and quantum dots for therapeutic, theranostic, diagnostic, biosensing, and analytical reasons. Within this review a concise summary and analysis of the current knowledge, future directions, and potential clinical use of thiolated NPs are provided.

Per-6-Thiolated Cyclodextrins: A Novel Type of Permeation Enhancing Excipients for BCS Class IV Drugs

The purpose of the study was to develop a per-6-thiolated α-cyclodextrin (α-CD) by substituting all primary hydroxyl groups of α-CD with thiol groups and to assess its solubility-improving and permeation-enhancing properties for a BCS Class IV drug in vitro as well as in vivo. The primary hydroxyl groups of α-CD were replaced by iodine, followed by substitution with -SH groups. The structure of per-6-thiolated α-CD was approved by FT-IR and ¹H NMR spectroscopy. The per-6-thiolated was characterized for thiol content, -SH stability, cytotoxicity, and solubility-improving properties by using the model BCS Class IV drug furosemide (FUR). The mucoadhesive properties of the thiolated oligomer were investigated via viscoelastic measurements with porcine mucus, whereas permeation-enhancing features were evaluated on the Caco-2 cell monolayer and rat gut mucosa. Furthermore, oral bioavailability studies were performed in rats. The per-6-thiolated α-CD oligomer displayed 4244 ± 402 μmol/g thiol groups. These -SH groups were stable at pH ≤ 4, exhibiting a pK_a value of 8.1, but subject to oxidation at higher pH. Per-6-thiolated α-CD was not cytotoxic to Caco-2 cells in 0.5% (m/v) concentration within 24 h. It improved the solubility of FUR in the same manner as unmodified α-CD. The addition of per-6-thiolated α-CD (0.5% m/v) increased the mucus viscosity up to 5.8-fold at 37 °C within 4 h. Because of the incorporation in per-6-thiolated α-CD, the apparent permeability coefficient (P_app) of FUR was 6.87-fold improved on the Caco-2 cell monolayer and 6.55-fold on the intestinal mucosa. Moreover, in vivo studies showed a 4.9-fold improved oral bioavailability of FUR due to the incorporation in per-6-thiolated α-CD. These results indicate that per-6-thiolated α-CD would be a promising auxiliary agent for the mucosal delivery of, in particular, BCS Class IV drugs.

Thiolated polymers: Bioinspired polymers utilizing one of the most important bridging structures in nature

Thiolated polymers designated "thiomers" are obtained by covalent attachment of thiol functionalities on the polymeric backbone of polymers. In 1998 these polymers were first described as mucoadhesive and in situ gelling compounds forming disulfide bonds with cysteine-rich substructures of mucus glycoproteins and crosslinking through inter- and intrachain disulfide bond formation. In the following, it was shown that thiomers are able to form disulfides with keratins and membrane-associated proteins exhibiting also cysteine-rich substructures. Furthermore, permeation enhancing, enzyme inhibiting and efflux pump inhibiting properties were demonstrated. Because of these capabilities thiomers are promising tools for drug delivery guaranteeing a strongly prolonged residence time as well as sustained release on mucosal membranes. Apart from that, thiomers are used as drugs per se. In particular, for treatment of dry eye syndrome various thiolated polymers are in development and a first product has already reached the market. Within this review an overview about the thiomer-technology and its potential for different applications is provided discussing especially the outcome of studies in non-rodent animal models and that of numerous clinical trials. Moreover, an overview on product developments is given.

Boosting Drug Discovery for Parkinson's: Enhancement of the Delivery of a Monoamine Oxidase-B Inhibitor by Brain-Targeted PEGylated Polycaprolactone-Based Nanoparticles

The current pharmacological treatments for Parkinson's disease only offer symptomatic relief to the patients and are based on the administration of levodopa and catechol-O-methyltransferase or monoamine oxidase-B inhibitors (IMAO-B). Since the majority of drug candidates fail in pre- and clinical trials, due largely to bioavailability pitfalls, the use of polymeric nanoparticles (NPs) as drug delivery systems has been reported as an interesting tool to increase the stealth capacity of drugs or help drug candidates to surpass biological barriers, among other benefits. Thus, a novel potent, selective, and reversible IMAO-B (chromone C27, IC50 = 670 ± 130 pM) was encapsulated in poly(caprolactone) (PCL) NPs by a nanoprecipitation process. The resulting C27-loaded PEGylated PCL NPs (~213 nm) showed high stability and no cytotoxic effects in neuronal (SH-SY5Y), epithelial (Caco-2), and endothelial (hCMEC/D3) cells. An accumulation of PEGylated PCL NPs in the cytoplasm of SH-SY5Y and hCMEC/D3 cells was also observed, and their permeation across Caco-2 and hCMEC/D3 cell monolayers, used as in vitro models of the human intestine and blood-brain barrier, respectively, was demonstrated. PEGylated PCL NPs delivered C27 at concentrations higher than the MAO-B IC50 value, which provides evidence of their relevance to solving the drug discovery pitfalls.

Labrasol-Enriched Nanoliposomal Formulation: Novel Approach to Improve Oral Absorption of Water-Insoluble Drug, Carvedilol

The purpose of the current study was to develop a novel liposomal formulation to improve the oral bioavailability of carvedilol, a Biopharmaceutics Classification System class II with poor aqueous solubility and extensive presystemic metabolism. Conventional and various surfactant-enriched carvedilol-loaded liposomes were prepared by thin film hydration technique and physicochemical properties of liposomes (including size, encapsulation efficiency, release behavior, and morphology) were evaluated. To assess the oral bioavailability, in vivo studies were carried out in eight groups of male Wistar rats (n = 6) and the drug plasma concentration was determined. Conventional and surfactant containing liposomes showed average particle size of 76-104 nm with a narrow size distribution, high encapsulation efficiency (80%≤) and a sustained release profile in simulated intestinal fluid. Compared to the suspension, conventional and Labrasol containing liposomes significantly improved the oral bioavailability and peak plasma concentration of carvedilol. Biocompatibility studies (cell cytotoxicity and histopathological analyses) showed that the enhancing effect might be achieved without any apparent toxicity in the intestine. Decreased oral absorption of carvedilol nanovesicles by using a chylomicron flow blocker indicated contribution of lymphatic transport in nanocapsules absorption. The results reported the successful development of biocompatible Labrasol-enriched carvedilol nanoliposomal formulation with a significant oral enhancement capability. Graphical Abstract ᅟ.

Recellularized Native Kidney Scaffolds as a Novel Tool in Nephrotoxicity Screening

Drug-induced kidney injury in medicinal compound development accounts for over 20% of clinical trial failures and involves damage to different nephron segments, mostly the proximal tubule. Yet, currently applied cell models fail to reliably predict nephrotoxicity; neither are such models easy to establish. Here, we developed a novel three-dimensional (3D) nephrotoxicity platform on the basis of decellularized rat kidney scaffolds (DS) recellularized with conditionally immortalized human renal proximal tubule epithelial cells overexpressing the organic anion transporter 1 (ciPTEC-OAT1). A 5-day SDS-based decellularization protocol was used to generate DS, of which 100-μm slices were cut and used for cell seeding. After 8 days of culturing, recellularized scaffolds (RS) demonstrated 3D-tubule formation along with tubular epithelial characteristics, including drug transporter function. Exposure of RS to cisplatin (CDDP), tenofovir (TFV), or cyclosporin A (CsA) as prototypical nephrotoxic drugs revealed concentration-dependent reduction in cell viability, as assessed by PrestoBlue and Live/Dead staining assays. This was most probably attributable to specific uptake of CDDP by the organic cation transporter 2 (OCT2), TFV through organic anion transporter 1 (OAT1), and CsA competing for P-glycoprotein-mediated efflux. Compared with 2D cultures, RS showed an increased sensitivity to cisplatin and tenofovir toxicity after 24-hour exposure (9 and 2.2 fold, respectively). In conclusion, we developed a physiologically relevant 3D nephrotoxicity screening platform that could be a novel tool in drug development.

Placental control of drug delivery

The placenta serves as the interface between the maternal and fetal circulations and regulates the transfer of oxygen, nutrients, and waste products. When exogenous substances are present in the maternal bloodstream-whether from environmental contact, occupational exposure, medication, or drug abuse-the extent to which this exposure affects the fetus is determined by transport and biotransformation processes in the placental barrier. Advances in drug delivery strategies are expected to improve the treatment of maternal and fetal diseases encountered during pregnancy.

BZML, a novel colchicine binding site inhibitor, overcomes multidrug resistance in A549/Taxol cells by inhibiting P-gp function and inducing mitotic catastrophe

Multidrug resistance (MDR) interferes with the efficiency of chemotherapy. Therefore, developing novel anti-cancer agents that can overcome MDR is necessary. Here, we screened a series of colchicine binding site inhibitors (CBSIs) and found that 5-(3, 4, 5-trimethoxybenzoyl)-4-methyl-2-(p-tolyl) imidazol (BZML) displayed potent cytotoxic activity against both A549 and A549/Taxol cells. We further explored the underlying mechanisms and found that BZML caused mitosis phase arrest by inhibiting tubulin polymerization in A549 and A549/Taxol cells. Importantly, BZML was a poor substrate for P-glycoprotein (P-gp) and inhibited P-gp function by decreasing P-gp expression at the protein and mRNA levels. Cell morphology changes and the expression of cycle- or apoptosis-related proteins indicated that BZML mainly drove A549/Taxol cells to die by mitotic catastrophe (MC), a p53-independent apoptotic-like cell death, whereas induced A549 cells to die by apoptosis. Taken together, our data suggest that BZML is a novel colchicine binding site inhibitor and overcomes MDR in A549/Taxol cells by inhibiting P-gp function and inducing MC. Our study also offers a new strategy to solve the problem of apoptosis-resistance.

Preactivated thiomers for intranasal delivery of apomorphine: In vitro and in vivo evaluation

The purpose of this study was to synthesize preactivated thiomers with different degrees of preactivation and to evaluate their potential as novel excipient for nasal apomorphine administration. The thiomer (PAA-cys) was synthesized by addition of thiol groups on poly(acrylic acid) with various molecular mass including 100, 250and450kDafollowed by immobilization of 2-mercaptonicotinic acid (2MNA) to thiol groups by disulfide bond formation resulting in PAA-cys-2MNA. These thiomers (PAA₁₀₀-cys, PAA₂₅₀-cys and PAA₄₅₀-cys) were in the next step preactivated by 56.3, 59.5 and 46.5% (medium degree), and 80.1, 81.6 and 87% (high degree), respectively. Apomorphine permeation across porcine nasal mucosa in the presence of PAA₁₀₀-cys-2MNA, PAA₂₅₀-cys-2MNA and PAA₄₅₀-cys-2MNA with high degree of preactivation was 3.1-, 4.4- and 4.1-fold, while 2.7-, 3.4- and 3.0-fold higher than control for medium degree of preactivation, respectively. Administration of apomorphine in the presence of PAA₂₅₀-cys-2MNA showed in rats 9 and ∼2-fold improvement of relative bioavailability compared with oral and intranasal administration of apomorphine solution, respectively. Because of the pronounced improvement among other polymers, PAA₂₅₀-cys-2MNA with high degree of preactivation could be considered as promising excipient for nasal delivery of apomorphine.

Measurement of Rhodamine 123 in Three-Dimensional Organoids: A Novel Model for P-Glycoprotein Inhibitor Screening

P-glycoprotein (P-gp), as the most important efflux transporter in intestines, plays the key role to determine the bioavailability of many drugs. The three-dimensional (3D) organoid model is suitable to imitate small intestinal epithelium. In this study, a rapid, sensitive and efficient method to measure rhodamine 123 (Rh123, P-gp substrate) in 3D organoids was developed to analyse P-gp-mediated drug transport. Ultrasonic cell disruptor was used to smash the organoid, and automatic microplate reader was used for detecting the concentration of Rh123 (λex /λem = 485/520 nm). Moreover, verapamil, quinidine and mitotane were used to make validation about this newly developed approach. All three P-gp inhibitors significantly inhibited the transport of Rh123 into 3D organoids. Therefore, the above-mentioned method could serve as a new model for P-gp inhibitor screening in a high-throughput way.