Cannabidiol Inhibits In Vitro Human Liver Microsomal Metabolism of Remdesivir

Introduction: The year 2020 began with the world being flounced with a wave of novel coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) disease, named COVID-19. Based on promising pre-clinical and clinical data, remdesivir (RDV) was the first drug to receive FDA approval and so far, it is the most common therapy for treatment of SARS-CoV-2/MERS-CoV. However, following intravenous administration, RDV metabolizes majorly by human liver carboxylesterase 1 (CES1) and marginally by the CYP3A4 enzyme in merely less than an hour. Its resultant active metabolite is a hydrophilic nucleoside with very limited accumulation within lung tissues. Therefore, there is a need to investigate strategies to overcome such premature metabolism issues and improve the antiviral efficacy of RDV at the target site. Objective: Considering the major CES1-mediated metabolism of RDV on systemic administration, we intend to explore the remarkable CES1 plus CYP3A4 inhibitory activity of cannabidiol (CBD) against in vitro microsomal metabolism of RDV to indicate its therapeutic potential as an adjuvant to RDV in the treatment and management of COVID-19. Methods: We investigated the in vitro human liver microsomal metabolism of RDV in the presence of two potential CES1 inhibitors-CBD and nelfinavir, and two standard CYP3A4 inhibitors-ritonavir (RITO) and cyclosporin A. The microsomal metabolism assay was further validated by using a well-characterized CYP3A4-selective substrate, midazolam (MDZ), in the presence of CBD and RITO. Results: Our findings depicted that RDV was rapidly and completely metabolized by human liver microsomes within 60 min. Coincubation with CBD substantially reduced microsomal metabolism of RDV and prolonged its in vitro half-life from 8.93 to 31.07 min. CBD showed significantly higher inhibition of RDV compared with known CES1 and CYP3A4 inhibitors. Inhibition of MDZ metabolism by CBD and RITO further validated the assay. Conclusions: The current study strongly suggests that CBD significantly inhibits human liver microsomal metabolism of RDV and extends its in vitro half-life. Thus, concomitant administration of CBD with RDV intravenous injection could be a promising strategy to prevent premature metabolism in COVID-19 patients.

Development of a safe pediatric liquisolid self-nanoemulsifying system of triclabendazole for the treatment of fascioliasis

Fascioliasis, a common parasitic infection observed in the pediatric patient population, is a leading cause of concern in countries with poor/unhealthy water resources. To treat this condition first line agent such as triclabendazole (TBZ) has been the choice therapy. However, there is a major hurdle in exploiting TBZ. Characterized with poor aqueous solubility (0.1 mg/L), its solubility has been the rate limiting factor, rendering requirement of large doses of TBZ. To address the same, the focus of the current study was to develop a self-nano emulsifying drug delivery system (TBZ-SNEDDS) for TBZ and developing dose customizable pediatric dispersible color-coded tablets. TBZ-SNEDDS were successfully formulated by using Kolliphor®EL, as a surfactant, a lipid phase of medium chain triglyceride and α-tocopherol in the ratio of (1:1), with dimethylacetamide (DMA) as a solvent. It was observed during in vitro release studies that there was a significant effect of fed conditions on the rate of TBZ release from the formulation. greater than 85 % TBZ was observed to release in fed conditions in comparison to fasted conditions. As currently TBZ is prescribed on a weight-based dosage regimen, it is imperative to develop a dose-customizable fast dissolving pediatric formulation. Hence, TBZ-SNEDDS could prove to be pivotal in helping countless children around the world in desperate conditions to get cheap yet effective therapy.

In vitro assessment of a synergistic combination of gemcitabine and zebularine in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers with an extremely poor prognosis. Gemcitabine (Gem) is still the mainstay drug for the treatment of PDAC. However, rapid inactivation by cytidine deaminase (CDA) present in pancreatic cancer cells severely limits anticancer efficacy of Gem. In this study, we investigated the effect of a CDA inhibitor - Zebularine (Zeb) on anticancer activity of Gem in pancreatic cancer cell lines MiaPaCa-2, BxPC-3, and Panc-1. Zeb treatment synergistically increased Gem-induced cytotoxicity in all three pancreatic cancer cell lines. The strongest synergistic activity was found at 1:10 M ratio of Gem/Zeb (combination index 0.04-0.4). Additionally, Gem + Zeb treated cells showed marked decreased in the expressions of anti-apoptotic protein including Bcl-2 and survivin while significantly increased the cleaved caspase-3, and loss of mitochondrial membrane potential was observed. Multicellular 3D spheroids of MiaPaCa-2 cells treated with combination showed significant reduction (25-60%) in spheroid size, weight compared to single drug and control group. Live/dead cell imaging showed that Gem + Zeb treated spheroids exhibited a highly distorted surface with significantly higher number of dead cells (red). The results of the present study confirm that this synergistic combination is worthy of future investigations as a potential approach for the treatment of PDAC.

Abstract 1059: Combination of gemcitabine and cytidine deaminase inhibitor: A breakthrough cocktail for the treatment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma is a very common type of pancreatic cancer and is one of the deadliest cancers. Gemcitabine (Gem), is still the mainstay drug for the treatment of PDAC. Gem is a hydrophilic drug which requires nucleoside transporters for its efficient uptake. Once inside the cell, Gem is converted to an active triphosphate form which inhibits DNA synthesis and causes apoptosis. However, Gem gets inactivated by cytidine deaminase (CDA). Long term treatment with Gem leads to increased CDA production thereby developing resistance. We hypothesize that combination of Gem with CDA inhibitor like Zebularine (Zeb), could prevent the intracellular degradation of Gem. Combination can potentially result in enhancing the anti-cancer activity of Gem, reduced dose and dosing frequency and minimizing side effects. The objectives of our study were; (a) to investigate the cytotoxic interaction of Gem and Zeb alone and in combination (b) Evaluating effect of various apoptosis and proliferation markers using flow cytometry and western blot assay. Initially we explored the anti-proliferative effects of Gem and Zeb as a single drug and in combination on MiaPaca-2 cells using MTT assay. Combination index was calculated using chou talalay method and Combenefit software. Effect of Gem, Zeb, and combination treatment on the cell viability of 3D tumor spheroids and its area was carried out using fluorescence microscopy and ImageJ software respectively. Apoptosis study was carried out using Annexin V apoptosis kit.Gem and Zeb exhibited dose-dependent inhibition in viability of MiaPaca-2 cells with an IC50 of 0.48 and 67.82 µM, respectively. The combination index of 0.09 suggest “very strong synergism” (Table 1). 3D spheroid treated with combination exhibited a highly distorted surface with significantly higher number of dead cells. Our research confirms that this synergistic combination can be a breakthrough approach for the treatment of PDAC.

Table 1.IC50 of Gem, Zeb and combination of Gem+Zeb in Miapaca2 cellsDrugMolar RatioIC50 of GemIC50 of ZebCombination IndexSingle-0.4867.82Gem1:100.0440.40.09

Citation Format: Manali Patki, Aishwarya Saraswat, Shraddha Bhutkar, Vikas Dukhande, Ketankumar Patel. Combination of gemcitabine and cytidine deaminase inhibitor: A breakthrough cocktail for the treatment of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1059.

Aerosolized nanoliposomal carrier of remdesivir: an effective alternative for COVID-19 treatment in vitro

Aim: To formulate an aerosolized nanoliposomal carrier for remdesivir (AL-Rem) against coronavirus disease 2019. Methods: AL-Rem was prepared using modified hydration technique. Cytotoxicity in lung adenocarcinoma cells, stability and aerodynamic characteristics of developed liposomes were evaluated. Results: AL-Rem showed high encapsulation efficiency of 99.79%, with hydrodynamic diameter of 71.46 ± 1.35 nm and surface charge of -32 mV. AL-Rem demonstrated minimal cytotoxicity in A549 cells and retained monolayer integrity of Calu-3 cells. AL-Rem showed sustained release, with complete drug release obtained within 50 h in simulated lung fluid. Long-term stability indicated >90% drug recovery at 4°C. Desirable aerosol performance, with mass median aerodynamic diameter of 4.56 ± 0.55 and fine particle fraction of 74.40 ± 2.96%, confirmed successful nebulization of AL-Rem. Conclusion: AL-Rem represents an effective alternative for coronavirus disease 2019 treatment.

Self-injectable extended release formulation of Remdesivir (SelfExRem): A potential formulation alternative for COVID-19 treatment

There has been a growing and evolving research to find a treatment or a prevention against coronavirus 2019 (COVID-19). Though mass vaccination will certainly help in reducing number of COVID-19 patients, an effective therapeutic measure must be available too. Intravenous remdesivir (RDV) was the first drug receiving Food and Drug Administration (FDA) approval for the treatment of COVID-19. However, in a pandemic like COVID-19, it is essential that drug formulations are readily available, affordable and convenient to administer to every patient around the globe. In this study, we have developed a Self-injectable extended release subcutaneous injection of Remdesivir (SelfExRem) for the treatment of COVID-19. As opposed to intravenous injection, extended release subcutaneous injection has the benefits of reducing face-to-face contact, minimizing hospitalization, reducing dosing frequency and reducing overall health care cost. SelfExRem was developed using a biodegradable polymer, poly(lactic-co-glycolic acid) (PLGA), dissolved in a biocompatible vehicle. Six different batches were formulated using 2 different grades of low molecular weight PLGA and 3 different PLGA concentration. The force of injection of various polymeric solutions through 23–30-gauge needles were analyzed using a TA.XTplus texture analyzer. The time required for injection was evaluated both manually and by using an autoinjector. In vitro release of all the batches were carried out in 1% v/v tween 80 in phosphate buffer saline. The study indicated that SelfExRem developed with 15% w/v PLGA (75:25) provided a steady release of drug for 48 h and may be a breakthrough approach for the treatment of COVID-19.

Process optimization of twin-screw melt granulation of fenofibrate using design of experiment (DoE)

The purpose of this study was to optimize the melt granulation process of fenofibrate using twin-screw granulator. Initial screening was performed to select the excipients required for melt granulation process. A 3 × 3 factorial design was used to optimize the processing conditions using the % drug loading (X₁) and screw speed (X₂) as the independent parameters and granule friability (Y₁) % yield (Y₂) as the dependent parameters. The effect of the independent parameters on the dependent parameters was determined using response surface plots and contour plots. A linear relationship was observed between % drug loading (X₁) and % friability (Y₁) and a quadratic relationship was observed between the independent parameters (X₁ and X₂) and % yield (Y₂). The processing conditions for optimum granules were determined using numerical and graphical optimization and it was found that 15% drug loading at 50 rpm results in maximum % yield of 82.38% and minimum friability of 7.88%. The solid-state characterization of the optimized granules showed that the drug turned from crystalline state to amorphous state during melt granulation process. The optimized granules were compressed into tablets using Purolite® as the super disintegrating agent. The optimized formulation showed >85% drug release in 0.75% SLS solution within 60 min.

Overdose and Alcohol Sensitive Immediate Release System (OASIS) for Deterring Accidental Overdose or Abuse of Drugs

Death from an accidental or intentional overdose of sleeping tablets has increased exponentially in the USA. Furthermore, the simultaneous consumption of sleeping tablets with alcoholic beverages not only intensifies the effect of sleeping tablets but also leads to blackouts, sleepwalking, and death in many cases. In this article, we proposed a unique and innovative technology to prevent multi-tablet and alcohol-associated abuse of sleeping tablet. Agonist- and antagonist-loaded polymeric filaments of appropriate Eudragit® polymers were prepared using hot melt extrusion. Metoprolol tartrate and hydrochlorothiazide were used as model drugs in place of zolpidem tartrate (agonist-BCS class I) and flumazenil (antagonist-BCS class IV), respectively. Crushed filaments were converted into a tablet with a novel rapidly soluble co-processed alkalizing agent. Dissolution studies of single tablet and multiple tablets (5) in fasted state simulated gastric fluid (FaSSGF) confirmed that the release of the agonist was significantly (p < 0.0001) reduced in multi-tablet dissolution. Furthermore, the release of antagonist was significantly higher when tablet was exposed to FaSSGF+20% ethanol and various alcoholic beverages. Thus, appropriate use of Eudragit® polymer's chemistry could help design a tablet to prevent the release of agonist in case of overdose and simultaneous release of antagonist when consumed with alcohol.

Nanoformulation of PROteolysis TArgeting Chimera targeting ‘undruggable’ c-Myc for the treatment of pancreatic cancer

Aim: To explore the anticancer activity of a novel BRD4 protein degrader ARV-825 (ARV) and its nanoformulation development (ARV-NP) for treatment of pancreatic cancer. Materials & methods: ARV-NP were prepared using nanoprecipitation method and characterized for their physicochemical properties and various anticancer cell culture assays. Results: ARV-NP (89.63 ± 16.39 nm) demonstrated good physical stability, negligible hemolysis and improved half-life of ARV. ARV-NP showed significant cytotoxicity, apoptosis and anticlonogenic effect in pancreatic cancer cells. Significant downregulation of target proteins BRD4, c-Myc, Bcl-2 and upregulation of apoptotic marker cleaved caspase-3 was observed. Most importantly, ARV-NP treatment significantly inhibited the cell viability of 3D tumor spheroids of pancreatic cancer. Conclusion: ARV-NP represents a novel therapeutic strategy for pancreatic cancer.

Efavirenz nanomicelles loaded vaginal film (EZ film) for preexposure prophylaxis (PrEP) of HIV

Preexposure prophylaxis (PrEP) using oral or vaginal microbicide is an emerging and effective strategy to prevent HIV transmission. Vaginal film is becoming more acceptable and a convenient dosage form compared to cream, gel and suppository. Extremely poor aqueous solubility of efavirenz (EFV) limits its use as vaginal microbicide. The aim of this study was to develop and evaluate a monomeric surfactant free, rapidly soluble vaginal film of EFV (EZ film). EZ film was prepared using a tetrafunctional block polymer (Tetronic 1107), carrageenan and polyvinyl alcohol (PVA) by solvent evaporation method. First, different solubilizers were screened for EFV solubility, in vitro cytotoxicity and cell membrane integrity assay on HeLa cells. Optimized film was characterized for solid state, mechanical strength, epithelial integrity, in vitro drug release in simulated vaginal fluid (SVF), simulated seminal fluid (SSF) and in vitro anti-HIV activity. Optimized EZ film showed a particle size of 48 ± 3.8 nm with PDI of 0.299. Differential scanning colorimetry (DSC) thermogram suggested the complete amorphization of EFV within the film. EZ film rapidly disintegrated (30 s) with complete release of EFV in SVF and SSF. The film was found to be non-toxic to HeLa cells and showed similar anti-HIV-1 activity as that of EFV in DMSO. EZ film did not show any significant change in the TEER value in HEC 1A cell line. Hence, the findings from the current study strongly suggest that the EZ film could be a cost-effective and convenient dosage form for PrEP of HIV.

A vaginal nanoformulation of a SphK inhibitor attenuates lipopolysaccharide-induced preterm birth in mice

Aim: Previously, we have shown that inhibition of SphK by the SphK inhibitor-II (SKI II) prevents lipopolysaccharide-induced preterm birth in mice. The aim of this study was to develop a vaginal self-nanoemulsifying drug-delivery system (SNEDDS) for SKI II. Materials & methods: A SKI II-loaded SNEDDS was characterized and tested in a murine preterm birth model. Results: The SNEDDS immediately formed a gel and then slowly emulsified to nanoglobules with over 500-fold enhancement of SKI II solubility at vaginal pH. Intravaginal administration of the SKI II SNEDDS significantly decreased lipopolysaccharide-induced preterm birth in mice. Conclusion: A vaginal nanoformulation of SKI II represents a novel, noninvasive approach to prevent preterm birth.

Development of an Arginine Anchored Nanoglobule with Retrograde Trafficking Inhibitor (Retro-2) for the Treatment of an Enterohemorrhagic Escherichia coli Outbreak

Enterohemorrhagic Escherichia coli O157:H7 (EHEC) or Shiga toxin-producing E. coli (STEC) is known to cause sporadic and epidemic gastrointestinal infections with several incidences of outbreaks. Antibiotic-based therapy further worsens the condition by facilitating the release of Shiga toxins (Stx) and lipopolysaccharides (LPS). Hence, there is an urgent need to develop an antibiotic-free, safe, and effective therapeutic intervention for the treatment of EHEC infections. We proposed a novel therapeutic strategy to address this clinical problem-kill, capture, and inhibit. We aimed to formulate and characterize lauroyl arginate ethyl ester (LAE) and Retro-2 loaded self-nano emulsifying drug delivery systems (SNEDDS). Retro-2 is a recently developed novel class of molecule, which can selectively inhibit retrograde transport of Stx. In this paper, we first carried out preformulation studies of Retro-2, followed by the development of SNEDDS forming arginine anchored nanoglobules (AR-NG), characterization of LPS binding to AR-NG, and finally evaluation of activity against EHEC. Retro-2 showed extremely poor solubility at all gastrointestinal pH values, susceptibility to acidic environments, and good permeability. The positively charged AR-NG spontaneously formed a globule size of 102.8 ± 1.9 nm with a surface charge of +52.15 ± 3 mV and increased the solubility of Retro-2. Further, binding and aggregation of LPS and AR-NG were confirmed by particle size, polydispersity index, zeta potential, fluorescent intensity, turbidity analysis, and a limulus amebocyte lysate (LAL) test. Additionally, a significant reduction in LPS induced TNF-α was observed in AR-NG treated macrophages. Thus, in this paper, we demonstrate a very promising and innovative therapeutic approach based on the "kill (E. Coli), capture (released LPS), and inhibit (transport of Stx)" concept.

Multi-dose oral abuse deterrent formulation of loperamide using hot melt extrusion

Loperamide, an over the counter anti-diarrheal drug, also infamously referred to as "poor man's methadone". Due to the ease of availability and low price, people/patients abuse it by consuming more than 30 tablets to achieve euphoric effect and to combat opioid withdrawal. But supratherapeutic doses of loperamide result in severe respiratory depression, cardiac dysrhythmia and mortality. To address this issue, we developed a unique and innovative technology to deter multi-dose oral abuse. The concept is to design a tablet which can immediate release loperamide in diarrheic patients (single tablet) while stops loperamide release in case of intentional multi-dose ingestion. Loperamide was molecularly dispersed into gastric soluble cationic polymers - Eudragit® EPO and Kollicoat® Smartseal 100P using hot melt extrusion to obtain filament. Filaments were milled and compressed into tablets ((Eudragit® EPO (SJU1) and Kollicoat® Smartseal (SJU2)) with optimized amount of L-Arginine. Dissolution in 250 mL of Fasted state simulated gastric fluid (FaSSGF) revealed that single tablet of Imodium® (marketed formulation) and SJU1 showed >85% of release within 15 min. Most importantly, in multi-unit dissolution (15 tablets), Imodium® exhibited >90% release but SJU tablets showed <2% of drug release thus demonstrating its ability to deter multi-dose oral abuse.

Erlotinib-Valproic Acid Liquisolid Formulation: Evaluating Oral Bioavailability and Cytotoxicity in Erlotinib-Resistant Non-small Cell Lung Cancer Cells

Lung cancer patients develop acquired resistance to tyrosine kinase inhibitors including erlotinib (ERL) after few months of primary treatment. Evidently, new chemotherapy strategies to delay or overcome the resistance are urgently needed to improve the clinical outcome in non-small cell lung cancer (NSCLC) patients. In this paper, we have investigated the cytotoxic interaction of ERL and valproic acid (VA) in ERL-resistant NSCLC cells and developed a liquisolid formulation of ERL-VA for improving oral bioavailability of ERL. ERL is weakly basic, biopharmaceutical classification system (BCS) class II drug with extremely poor aqueous solubility while VA is a branched chain fatty acid. Ionic interaction between ERL and VA (1:2 M ratio) resulted in significant enhancement in saturation solubility of ERL at different pH range. Liquisolid formulation of ERL-VA (EVLF) developed using PEG 400 and mesoporous calcium silicate was characterized for solid state and in vitro dissolution in biorelevant dissolution medium (FaSSIF and FeSSIF). Cytotoxicity of ERL was enhanced by 2-5 folds on co-incubation with VA in HCC827/ERL cell line. Flow cytometry analysis using AnnexinV-FITC assay demonstrated that VA and ERL alone have poor apoptotic effect on HCC827/ERL cells while combination showed around 69% apoptotic cells. Western blot analysis confirmed the role of survivin in overcoming resistance. In vivo pharmacokinetic studies of EVLF in rats demonstrated a 199% relative bioavailability compared to ERL suspension. Thus, EVLF could be a promising alternative to current ERL formulations in the treatment of NSCLC.

Investigating the application of FDM 3D printing pattern in preparation of patient-tailored dosage forms

Aim: The aim of this work was to investigate the effect of printing pattern on physical attributes and dissolution of fused deposition modeling 3D printed caplets. Methods: Hydrochlorothiazide-loaded polyvinyl alcohol filaments were prepared by hot melt extrusion. Caplets printed in hexagonal (HexCap), diamond infill (DiaCap) in three different sizes using fused deposition modeling 3D printer and evaluated for hardness, disintegration and dissolution. Results: DiaCaps exhibited higher hardness than HexCaps. Disintegration time for HexCaps was <20 mins. while DiaCaps took 25–40 mins. DiaCaps showed 20–30% lower release at all time points compared with HexCaps. Conclusion: Although composition, processing parameters were same, mere change in printing pattern alters disintegration and dissolution. Findings of this study can be invaluable in developing patient-tailored medicines.

Abuse Deterrent Immediate Release Egg-Shaped Tablet (Egglets) Using 3D Printing Technology: Quality by Design to Optimize Drug Release and Extraction

Opioid abuse is a growing problem and has become a national health crisis over the past decade in the USA. Oral ingestion, snorting, and injection are the most commonly employed routes of abuse for an immediate release product. To circumvent these issues, we have developed an egg-shaped tablet (egglet) using fused deposition modeling (FDM) 3D printing technology. Drug-loaded polymeric filaments (1.5 mm) were prepared using hot melt extrusion (HME) followed by printing into egglets of different sizes and infill densities. Based on printability and crush resistance, polyvinyl alcohol (PVA) was found to be the most suitable polymer for the preparation of abuse deterrent egglets. Further, egglets were evaluated and optimized for mechanical manipulation using household equipment, milling, particle size distribution, solvent extraction, and drug release as per the FDA guidance (November 2017). A multifactorial design was used to optimize egglets for solvent extraction and drug release. Extreme hardness (> 500 N) and very large particle size (> 1 mm) on mechanical manipulation confirmed the snorting deterring property while less than 15% drug extraction in 5 min (% S_ext) demonstrated the deterrence for injection abuse. Quality target product profile D85 < 30 min and % S_ext < 15 was achieved with egglets of 6 mm diameter, 45% infill density, and 15% w/w drug loading. Dose of drug can be easily customized by varying dimension and infill density without altering the composition. HME coupled with FDM 3D printing could be a promising tool in the preparation of patient-tailored, immediate release abuse deterrent formulation.