Who volunteers for phase I clinical trials? Influences of anxiety,social anxiety and depressive symptoms on self-selection and the reporting of adverse events

Objective

To investigate the influence of anxiety, social anxiety and depressive symptoms on the willingness of healthy subjects to volunteer for phase I studies and to report adverse events.

Materials and methods

A group of healthy subjects who had never participated in a clinical trial (“Naïve Subjects”) were invited to participate in a phase I study. All subjects were assessed for trait anxiety (State-Trait Anxiety Inventory, STAI-T), social anxiety (Social Avoidance and Distress, SAD, and Fear of Negative Evaluation, FNE) and depressive symptomatology (Beck Depression Inventory, BDI-II). Subjects who accepted the invitation to participate were compared with those who refused. The personality traits of a group of “Actual Participants” were examined, and the relation of these traits to adverse events reported during participation was evaluated.

Results

A significant inverse correlation was found between the STAI-T (R?=??0.203, p?R?=??0.204, p?Z?=??2.600, p?Z?=?2.524, p?p?p?

Conclusion

Participants in phase I studies are a self-selected sample defined by low trait-anxiety and social avoidance behaviors. This self-selection bias may affect the study results because less anxious subjects tend to report fewer adverse events. The characterization of a participant’s personality traits may be important in phase I studies.

     

A Study on Toxicity of Chemically Synthesised Silver Nanoparticle on <Emphasis Type="Italic">Eudrilus eugeniae</Emphasis>

Objective

To evaluate the toxicity of the silver nanoparticle against earthworms - Eudrilus eugeniae, a model for soil organism.

Methods

Silver nanoparticles were synthesised by chemical reduction and further characterised by UV Visible Spectroscopy and FeSEM. Earthworms were allowed to interact with different concentrations of the synthesized silver nanoparticles. After exposure period, histology and inductively coupled plasma optical emission spectrometry (ICP-OES) were done to determine the accumulation and toxic effects exhibited by the nanoparticle on earthworms.

Results

The synthesized nanoparticle was found to be between the size of 180 and 200 nm. Histology studies revealed that silver nanoparticles to cause fibrosis, lipofuscin-like deposits and also gut disruption in earthworms.

Conclusion

Silver nanoparticles were found to be toxic to Eudrilus eugeniae, which was evidenced by histology.

     

Utility of Göttingen minipigs for Prediction of Human Pharmacokinetic Profiles After Dermal Drug Application

Purpose

Although Göttingen minipigs have been widely used for the evaluation of skin absorption, the correlation of minipig skin permeability with human skin absorption remains unclear. This study was designed to investigate the prediction of human plasma concentrations after dermal application of drug products using skin permeability data obtained from minipigs.

Methods

First, in vitro skin permeabilities of seven marketed transdermal drug products were evaluated in minipigs, and compared with in vitro human skin permeability data. Next, plasma concentration-time profiles in humans after dermal applications were simulated using the in vitro minipig skin permeability data. Finally, the in vitro-in vivo correlation of minipig skin permeability was assessed.

Results

The in vitro skin permeabilities in minipigs were correlated strongly with in vitro human skin permeability data for the same drug products, indicating the utility of minipig skin as an alternative to human skin for in vitro studies. The steady-state plasma concentration or the maximum concentration of drugs was within 2-fold of the clinical data. Bioavailability was approximately 3-fold lower than in vitro permeated fraction.

Conclusions

Predictions using in vitro skin permeability data in Göttingen minipig skin can reproduce the human pharmacokinetic profile, although the prediction of in vivo skin absorption underestimates human absorption.

     

Hyaluronic Acid Layer-By-Layer (LbL) Nanoparticles for Synergistic Chemo-Phototherapy

Purpose

The aim of this study was to design hyaluronic acid (HA) layer-by-layer (LbL) nanoparticles, which carried paclitaxel (PTX) and Indocyanine green (ICG) to both tumor cells and tumor associated cells to achieve synergistic chemo-photothermal therapeutic effect.

Methods

The LbL-engineered nanoparticles (PDIH) were prepared by dopamine self-polymerization on PTX nanocrystal to form thin, surface-adherent polydopamine (PDA) films, which subsequently absorbed ICG and HA. The tumor cell and tumor associated cell targeting and antitumor efficacy of PDIH were investigated both in vitro an in vivo using 4 T1 murine mammary cancer cell lines and mice bearing orthotopic 4 T1 breast tumor.

Results

PDIH presented a long-rod shape in TEM and showed enhanced photothermal effect and cytotoxicity upon NIR laser irradiation both in vitro and in vivo. PDIH also displayed high target ability to CD44 overexpressed tumor cells and tumor associated cells mediated by HA. In vivo antitumor study indicated that PDIH therapeutic strategy could achieve remarkable antitumor efficacy.

Conclusion

PDIH showed excellent tumor-targeting property and chemo-photothermal therapeutic efficacy.

     

Population <Emphasis Type="BoldItalic">In Vitro-In Vivo</Emphasis> Correlation Model Linking Gastrointestinal Transit Time,pH, and Pharmacokinetics: Itraconazole as a Model Drug

Purpose

To establish an in vitro-in vivo correlation (IVIVC) model for Sporanox and SUBA-itraconazole formulations and to understand the impact of gastrointestinal (GI) pH and transit times on itraconazole dissolution and absorption.

Methods

IVIVC was developed based on fed/fasted pharmacokinetic data from randomized cross-over trials, in vitro dissolution studies, and prior information about typical and between subject variability of GI pH and transit times. Data were analysed using the population modelling approach as implemented in NONMEM.

Results

Dissolution kinetics were described using first order models. The in vivo pharmacokinetics of itraconazole was described with a 2-compartment model with 4-transit absorption compartments. Pharmacokinetic profiles for fasted itraconazole periods were described based on the in vitro dissolution model, in vivo disposition model, and the prior information on GI pH and transit times. The IVIVC model indicated that drug dissolution in the fed state required an additional pH-independent dissolution pathway. The IVIVC models were presented in a ‘Shiny’ application.

Conclusion

An IVIVC model was established and internally evaluated for the two itraconazole formulations. The IVIVC model provides more insight into the observed variability of itraconazole pharmacokinetics and indicated that GI pH and transit times influence in vivo dissolution and exposure.

     

Exploring Variation in Known Pharmacogenetic Variants and its Association with Drug Response in Different Mexican Populations

Purpose

Information on genetic variants that affect the pharmacokinetics and pharmacodynamics (PK/PD) of drugs in different populations from Mexico is still an ongoing endeavor. Here, we investigate allele frequencies on pharmacogenetic targets in Mexican Mestizos and Natives from three different States and its association with drug efficacy in individuals receiving either anticoagulants or antipsychotic drugs.

Methods

Natives from three different states and Mestizo patients receiving acenocoumarol or antipsychotics were genotyped using the DMET microarray (Affymetrix).

Results

We provide a collection of genetic variants that indicate that there are 3-times more variation than similarities between populations from Mexico and major continental groups. These differences were observed in several relevant targets including ABCB1, SLCO1A1, NAT2, UGTs, TYMS, VKORC1, and NR1I3. Moreover, Mexican Mestizos also showed allele frequency differences when compared to Natives for variants on DPYD, ADH1A, CYP3A4, SLC28A3, and SLC28A1. Significant allele differences also arose among the three Native groups here studied, mostly for transporters of the ABC-binding cassette and the solute carrier gene family. Finally, we explored genotype-drug response associations and pinpointed variants on FMOs (coumarins), and GSTM1 (haloperidol).

Conclusions

These findings confirm previous results and further delve into the pharmacogenetics of Mexican populations including different Native groups.

     

Development and performance of npde for the evaluation of time-to-event models

Purpose

Normalised prediction distribution errors (npde) are used to graphically and statistically evaluate mixed-effect models for continuous responses. In this study, our aim was to extend npde to time-to-event (TTE) models and evaluate their performance.

Methods

Let V denote a dataset with censored TTE observations. The null hypothesis (H₀) is that observations in V can be described by model M. We extended npde to TTE models using imputations to take into account censoring. We then evaluated their performance in terms of type I error and power to detect model misspecifications for TTE data by means of a simulation study with different sample sizes.

Results

Type I error was found to be close to the expected 5% significance level for all sample sizes tested. The npde were able to detect misspecifications in the baseline hazard as well as in the link between the longitudinal variable and the survival function. The ability to detect model misspecifications increased as the difference in the shape of the survival function became more apparent. As expected, the power also increased as the sample size increased. Imputing the censored events tended to decrease the percentage of rejections.

Conclusions

We have shown that npde can be readily extended to TTE data and that they perform well with an adequate type I error.

     

A new <Emphasis Type="BoldItalic">in vitro</Emphasis> lipid digestion – <Emphasis Type="BoldItalic">in vivo</Emphasis> absorption model to evaluate the mechanisms of drug absorption from lipid-based formulations

Purpose

In vitro lipid digestion models are commonly used to screen lipid-based formulations (LBF), but in vitro-in vivo correlations are in some cases unsuccessful. Here we enhance the scope of the lipid digestion test by incorporating an absorption ‘sink’ into the experimental model.

Methods

An in vitro model of lipid digestion was coupled directly to a single pass in situ intestinal perfusion experiment in an anaesthetised rat. The model allowed simultaneous real-time analysis of the digestion and absorption of LBFs of fenofibrate and was employed to evaluate the influence of formulation digestion, supersaturation and precipitation on drug absorption.

Results

Formulations containing higher quantities of co-solvent and surfactant resulted in higher supersaturation and more rapid drug precipitation in vitro when compared to those containing higher quantities of lipid. In contrast, when the same formulations were examined using the coupled in vitro lipid digestion – in vivo absorption model, drug flux into the mesenteric vein was similar regardless of in vitro formulation performance.

Conclusion

For some drugs, simple in vitro lipid digestion models may underestimate the potential for absorption from LBFs. Consistent with recent in vivo studies, drug absorption for rapidly absorbed drugs such as fenofibrate may occur even when drug precipitation is apparent during in vitro digestion.

     

Co-Delivery of Ciprofloxacin and Colistin in Liposomal Formulations with Enhanced <Emphasis Type="BoldItalic">In Vitro</Emphasis> Antimicrobial Activities against Multidrug Resistant <Emphasis Type="BoldItalic">Pseudomonas aeruginosa</Emphasis>

Purpose

This study aims to develop liposomal formulations containing synergistic antibiotics of colistin and ciprofloxacin for the treatment of infections caused by multidrug-resistant Pseudomonas aeruginosa.

Methods

Colistin (Col) and ciprofloxacin (Cip) were co-encapsulated in anionic liposomes by ammonium sulfate gradient. Particle size, encapsulation efficiency, in vitro drug release and in vitro antibiotic activities were evaluated.

Results

The optimized liposomal formulation has uniform sizes of approximately 100 nm, with encapsulation efficiency of 67.0% (for colistin) and 85.2% (for ciprofloxacin). Incorporation of anionic lipid (DMPG) markedly increased encapsulation efficiency of colistin (from 5.4 to 67.0%); however, the encapsulation efficiency of ciprofloxacin was independent of DMPG ratio. Incorporation of colistin significantly accelerated the release of ciprofloxacin from the DMPG anionic liposomes. In vitro release of ciprofloxacin and colistin in the bovine serum for 2 h were above 70 and 50%. The cytotoxicity study using A549 cells showed the liposomal formulation is as non-toxic as the drug solutions. Liposomal formulations of combinations had enhanced in vitro antimicrobial activities against multidrug resistant P. aeruginosa than the monotherapies.

Conclusions

Liposomal formulations of two synergistic antibiotics was promising against multidrug resistant P. aeruginosa infections.

     

‘<Emphasis Type="BoldItalic">In Vitro</Emphasis>’, ‘<Emphasis Type="BoldItalic">In Vivo</Emphasis>’ and ‘<Emphasis Type="BoldItalic">In Silico</Emphasis>’ Investigation of the Anticancer Effectiveness of Oxygen-Loaded Chitosan-Shelled Nanodroplets as Potential Drug Vector

Purpose

Chitosan-shelled/decafluoropentane-cored oxygen-loaded nanodroplets (OLN) are a new class of nanodevices to effectively deliver anti-cancer drugs to tumoral cells. This study investigated their antitumoral effects ‘per se’, using a mathematical model validated on experimental data.

Methods

OLN were prepared and characterized either in vitro or in vivo. TUBO cells, established from a lobular carcinoma of a BALB-neuT mouse, were investigated following 48 h of incubation in the absence/presence of different concentrations of OLN. OLN internalization, cell viability, necrosis, apoptosis, cell cycle and reactive oxygen species (ROS) production were checked as described in the Method section.In vivo tumor growth was evaluated after subcutaneous transplant in BALB/c mice of TUBO cells either without treatment or after 24 h incubation with 10% v/v OLN.

Results

OLN showed sizes of about 350 nm and a positive surface charge (45 mV). Dose-dependent TUBO cell death through ROS-triggered apoptosis following OLN internalization was detected. A mathematical model predicting the effects of OLN uptake was validated on both in vitro and in vivo results.

Conclusions

Due to their intrinsic toxicity OLN might be considered an adjuvant tool suitable to deliver their therapeutic cargo intracellularly and may be proposed as promising combined delivery system.

     

Reformulation of Fungizone by PEG-DSPE Micelles: Deaggregation and Detoxification of Amphotericin B

Purpose

Fungizone® (AmB-SD), amphotericin B solubilized by sodium deoxycholate, contains a highly aggregated form of the antifungal agent that causes dose-limiting renal toxicity. With the aim of reducing the formulation’s toxicity by co-delivering monomeric amphotericin B (AmB) and sodium supplementation, we deaggregated AmB-SD with FDA-approved excipient PEG-DSPE in 0.9% NaCl-USP. Herein, we describe a reformulated AmB-SD with PEG-DSPE micelles that results in a less toxic drug with maintained antifungal activity.

Methods

We compared the aggregation state and particle size of AmB-SD alone or combined with PEG-DSPE micelles. In vitro hemolytic activity and in vivo renal toxicity were measured to determine the toxicity of different formulations. In vitro antifungal assays were performed to determine differences in efficacy among formulations.

Results

PEG-DSPE micelles in saline deaggregated AmB-SD. Deaggregated AmB-SD exhibited significantly reduced in vitro and in vivo toxicity. In vitro antifungal studies showed no difference in minimum inhibitory and fungicidal concentrations of AmB-SD combined with PEG-DSPE relative to the drug alone.

Conclusions

Reformulation of AmB-SD with PEG-DSPE micelles in saline facilitates co-delivery of monomeric AmB and sodium supplementation, potentially reducing the dose-limiting nephrotoxicity of AmB-SD. Ease of preparation and commercially available components lead us to acknowledge its potential for clinical use.

     

Synthesis,Characterization and Biocompatibility of <Emphasis Type="BoldItalic">N</Emphasis>-palmitoyl L-alanine-based Organogels as Sustained Implants of Granisetron and Evaluation of their Antiemetic Effect

Purpose

To assess the gelation power of N-palmitoyl L-alanine derivatives in injectable oils and to use the best chosen organogel as parenteral implant of granisetron for the treatment of emesis.

Methods

Twelve N-palmitoyl L-alanine derived organogels were developed and evaluated in terms of morphology, thermal properties and in vivo performance. The ability of the selected formula to form in situ gel upon subcutaneous injection in rats and its biocompatibility were monitored over 2 weeks by histopathological examination of the injection site.

Results

The acid derivative (N-palmitoyl L-alanine; PA) was superior to ester derivatives. The chosen formula (PA/safflower oil 10% w/v) was successful in forming an in situ gel of granisetron when subcutaneously injected in rats, lasting for 2 weeks and proved to be biocompatible by histopathological examination. Moreover, it exerted an extended antiemetic activity by decreasing the cisplatin-induced pica for a duration of 96 h and reduced preprotachykinin A mRNA expression and Substance P level for up to 4 days (gastric tissue) or 5 days (medulla oblongata) in rats.

Conclusion

Granisetron organogel could be considered as a safe, sustained-release and supportive anticancer treatment in both acute and chronic emesis as well as an accompanying treatment with chemotherapeutics in cancer cases.

     

<Emphasis Type="BoldItalic">CYP2D6</Emphasis> Genetic Variation and Beta-Blocker Maintenance Dose in Patients with Heart Failure

Purpose

This study examined whether a CYP2D6 polymorphism (CYP2D6*4) was related to beta-blocker maintenance dose in patients with heart failure.

Methods

Logistic regression modeling was utilized in a retrospective chart-review analysis of heart-failure patients (60% Male, 90% of European descent) to assess whether CYP2D6*4 (non-functional CYP2D6 allele present in 1 of 5 individuals of European descent) is associated with maintenance dose of carvedilol (n?=?65) or metoprolol (n?=?33).

Results

CYP2D6*4 was associated with lower maintenance dose of metoprolol (OR 0.13 [95% CI 0.02–0.75] p?=?0.023), and a trend was observed between CYP2D6*4 and higher maintenance dose of carvedilol (OR 2.94 [95% CI 0.84–10.30] p?=?0.093). None of the patients that carried CYP2D6*4 achieved the recommended target dose of metoprolol (200 mg/day).

Conclusion

Consistent with the role of CYP2D6 in the metabolism of metoprolol, the tolerated maintenance dose of metoprolol was lower in CYP2D6*4 carriers compared to non-carriers. Consistent with the role of CYP2D6 in activation of carvedilol, tolerated maintenance dose of carvedilol was higher in CYP2D6*4 carriers compared to non-carriers. Further investigation is warranted to ascertain the potential of CYP2D6 as a potential predictive biomarker of beta-blocker maintenance dose in heart failure patients.

     

Inflation of Type I Error in the Evaluation of Scaled Average Bioequivalence,and a Method for its Control

Purpose

To verify previously reported findings for the European Medicines Agency’s method for Average Bioequivalence with Expanding Limits (ABEL) for assessing highly variable drugs and to extend the assessment for other replicate designs in a wide range of sample sizes and CVs. To explore the properties of a new modified method which maintains the consumer risk ≤0.05 in all cases.

Methods

Monte-Carlo simulations of three different replicate designs covering a wide range of sample sizes and intra-subject variabilities were performed.

Results

At the switching variability of CV _wR 30% the consumer risk is substantially inflated to up to 9.2%, which translates into a relative increase of up to 84%. The critical region of inflated type I errors ranges approximately from CV _wR 25 up to 45%. The proposed method of iteratively adjusting α maintains the consumer risk at the desired level of ≤5% independent from design, variability, and sample size.

Conclusions

Applying the European Medicines Agency’s ABEL method at the nominal level of 0.05 inflates the type I error to an unacceptable degree, especially close to a CV _wR of 30%. To control the type I error nominal levels ≤0.05 should be employed. Iteratively adjusting α is suggested to find optimal levels of the test.

     

Vitamin E-rich Nanoemulsion Enhances the Antitumor Efficacy of Low-Dose Paclitaxel by Driving Th1 Immune Response

Purpose

To overcome the drawbacks of high dose regimen and improve the outcomes of chemotherapy at a low dose, an immunotherapeutic nanoemulsion based combination of chemotherapeutic agent (paclitaxel) with immunomodulatory agent (vitamin E) was developed and evaluated for their antitumor effect against breast cancer.

Methods

A total of five nanoemulsions loaded with various content of vitamin E were prepared and characterized. The immunoregulatory effects of vitamin E along with the overall antitumor efficacy of vitamin E-rich nanoemulsion with a low dose of paclitaxel were investigated through in vitro and in vivo experiments.

Results

Vitamin E-rich nanoemulsion exhibited relatively narrow size distribution, high entrapment efficiency and controlled in vitro release profile. In RAW264.7 cells, vitamin E-rich nanoemulsion significantly enhanced the secretion of Th1 cytokines and down-regulated the secretion of Th2 cytokine. In a co-culture system, vitamin E-rich nanoemulsion induced a high apoptosis rate in MDA-MB-231 cells as compared with vitamin E-low nanoemulsion. Furthermore, vitamin E-rich nanoemulsion exhibited superior in vivo antitumor efficacy in comparison with Taxol and vitamin E-low nanoemulsion at a paclitaxel dose of 4 mg/kg.

Conclusions

Vitamin E-rich nanoemulsion has great potential for the treatment of breast cancers with a low dose of paclitaxel via driving Th1 immune response.

     

Evaluation of Time Dependent Inhibition Assays for Marketed Oncology Drugs: Comparison of Human Hepatocytes and Liver Microsomes in the Presence and Absence of Human Plasma

Purpose

To evaluate an alternative in vitro system which can provide more quantitatively accurate drug drug interaction (DDI) prediction for 10 protein kinase inhibitors for which DDI risk was over-predicted by inhibition data generated in human liver microsomes (HLM).

Methods

Three cryopreserved human hepatocyte (hHEP) systems: 1) plated hHEPs; 2) hHEPs suspended in Dulbecco’s Modified Eagle Medium (DMEM) and 3) hHEPs suspended in human plasma (plasma hHEPs) were developed to detect CYP3A time dependent inhibition, and the static mechanistic model was used to predict clinical outcomes.

Results

A general trend was observed in the CYP3A inactivation potency (k _inact /K _{I, app} ) as HLM > plated > DMEM ≥ plasma hHEPs. Using the static mechanistic model, DDIs predicted using parameters estimated from plated, DMEM and plasma hHEPs had 84, 74 and 95% accuracy (out of 19 clinical interaction studies) within 2-fold of the reported interaction, respectively. They demonstrated significant improvement compared to the DDIs predicted using parameters estimated from HLMs where 58% accuracy was obtained.

Conclusions

Based on 19 DDIs, plasma hHEPs demonstrate a more reliable clinical DDI prediction for 10 protein kinase inhibitors and prototypical CYP3A time dependent inhibitors.

     

CpG-PEG Conjugates and their Immune Modulating Effects after Systemic Administration

Purpose

Synthetic oligodeoxynucleotides (ODN) containing unmethylated CpG motifs were found to be able to target cells that express Toll-like receptor 9 to modulate innate and adaptive immune reactions. But their in vivo application in immunotherapy against cancer has not been successful. We attempted in this study to examine polyethylene-glycol (PEG) conjugated CpG ODNs and investigated their mechanism of immune modulation in anti-cancer therapy.

Methods

CpG-PEG conjugates with different PEG lengths were synthesized. In vitro activity as well as in vivo pharmacokinetics and pharmacodynamics properties were evaluated.

Results

CpG-PEG20Ks were found to be able to persist longer in circulation and activate various downstream effector cells. After intravenous injection, they resulted in higher levels of IL-12p70 in the circulation and lower M-MDSC infiltrates in the tumor microenvironment. Such activities were different from those of CpG ODNs without PEGylation, suggesting different PK-PD profiles systemically and locally.

Conclusions

Our data support the development of CpG-PEGs as a new therapeutic agent that can be systemically administered to modulate immune responses and the microenvironment in tumor tissues.

     

Indinavir Alters the Pharmacokinetics of Lamivudine Partially <Emphasis Type="Italic">via</Emphasis> Inhibition of Multidrug and Toxin Extrusion Protein 1 (MATE1)

Purpose

Lamivudine, a characterized substrate for human multidrug and toxin extrusion protein 1 (hMATE1) in vitro, was commonly used with indinavir as a therapy against human immunodeficiency virus (HIV). We aimed to investigate whether mouse MATE1 is involved in the disposition of lamivudine in vivo, and whether there is any transporter-mediated interaction between indinavir and lamivudine.

Methods

The role of MATE1 in the disposition of lamivudine was determined using Mate1 wild type (+/+) and knockout (?/?) mice. The inhibitory potencies of indinavir on lamivudine uptake mediated by OCT2 and MATE1 were determined in human embryonic kidney 293 (HEK 293) cells stably expressing these transporters. The role of MATE1 in the interaction between indinavir and lamivudine in vivo was determined using Mate1 (+/+) and Mate1 (?/?) mice.

Results

The plasma concentrations and tissue accumulation of lamivudine were markedly elevated in Mate1 (?/?) mice as compared to those in Mate1 (+/+) mice. Indinavir significantly increased the pharmacokinetic exposure of lamivudine in mice; however, the effect by indinavir was significantly less pronounced in Mate1 (?/?) mice as compared to Mate1(+/+) mice.

Conclusion

MATE1 played an important role in lamivudine pharmacokinetics. Indinavir could cause drug-drug interaction with lamivudine in vivo via inhibition of MATE1 and additional mechanism.