Pharmacokinetics

Concentrations of psychoactive substances in blood samples from non-fatal and fatal opioid overdoses

Aim

The primary aim was to compare concentrations of psychoactive substances in blood in non‐fatal and fatal opioid overdoses. The secondary aim was to assess the concentration levels of naloxone in blood in non‐fatal overdoses and the association between naloxone findings and concomitantly detected drugs.

Method Design

Case‐control study.

Setting

Norway. Fatal overdoses from 2017 and non‐fatal overdoses from February 2018 to September 2019.

Cases

Thirty‐one non‐fatal and 160 fatal opioid overdose cases. Data from the non‐fatal overdoses were collected from hospital records and blood samples, and data from the fatal overdoses were collected from autopsy reports. Concentrations of psychoactive substances (including ethanol) in blood samples were collected at the time of hospital admission for the non‐fatal overdoses and during autopsy for the fatal overdoses.

Results

The median number of different substances detected was four for fatal and five for non‐fatal overdoses. The fatal overdoses had higher pooled concentrations of opioids (188 vs 57.2 ng/mL, P < .001), benzodiazepines (5467 vs 2051 ng/mL, P = .005) and amphetamines (581 vs 121 ng/mL, P < .001) than the non‐fatal overdoses. A linear relationship between naloxone and concomitant pooled opioid concentrations was found (95% confidence interval = 0.002‐0.135, P < .05).

Conclusion

The total load of drug concentrations was associated with the fatal outcome of an overdose, while the number of drugs used, to a lesser extent, differentiated between those who survived and those who died from an overdose. Higher opioid concentrations were associated with treatment with higher naloxone doses.

DoseCal: a virtual calculator for dosage conversion between human and different animal species

CONTEXT

The scientists as well as pharmacologists frequently convert the dose of drugs or extracts between human and different animal species. According to the literature, the extrapolation of the dose by simple conversion based only on body weight is not an accurate method. The miscalculation of dosage conversion may result in adverse effects due to overdose or reduced potency due to underdose.

AIM

To develop a conversion calculator with factual factor like K_m factor.

METHOD

The virtual calculator was developed as a web-based application using hypertext pre-processor programming language. My SQL software was used to store the data related to DoseCal.

RESULTS

Based on the K_m factor, dose conversion calculator called DoseCal was developed. The DoseCal would provide the dosage for both per kg and actual weight of the animal taken for the experiment.

CONCLUSION

The DoseCal would assist scientists in the dosage conversion easily and accurately between species.

Identification of the potential mechanism of Radix pueraria in colon cancer based on network pharmacology

Radix Puerariae (RP), a dry root of Pueraria lobata (Willd.) Ohwi, is used to treat a variety of diseases, including cancer. Several in vitro and in vivo studies have demonstrated the efficacy of RP in the treatment of colon cancer (CC). However, the biological mechanism of RP in the treatment of colon cancer remains unclear. In this study, the active component of RP and its potential molecular mechanism against CC were studied by network pharmacology and enrichment analysis. The methods adopted included screening active ingredients of Chinese medicine, predicting target genes of Chinese medicine and disease, constructing of a protein interaction network, and conducting GO and KEGG enrichment analysis. Finally, the results of network pharmacology were further validated by molecular docking experiments and cell experiments. Eight active constituents and 14 potential protein targets were screened from RP, including EGFR, JAK2 and SRC. The biological mechanism of RP against CC was analysed by studying the relationship between active components, targets, and enrichment pathways. These findings provide a basis for understanding the clinical application of RP in CC.

Current perspective on veterinary drug and chemical residues in food of animal origin

The marked increase in the demand for animal protein of high quality necessitates protecting animals from infectious diseases. This requires increasing the use of veterinary therapeutics. The overuse and misuse of veterinary products can cause a risk to human health either as short-term or long-term health problems. However, the biggest problem is the emergence of resistant strains of bacteria or parasites. This is in addition to economic losses due to the discarding of polluted milk or condemnation of affected carcasses. This paper discusses three key points: possible sources of drug and chemical residues, human health problems, and the possible method of control and prevention of veterinary drug residues in animal products.

Application of Semi-Mechanistic Pharmacokinetic and Pharmacodynamic Model in Antimicrobial Resistance

Antimicrobial resistance is a major public health issue. The pharmacokinetic/pharmacodynamic (PK/PD) model is an essential tool to optimize dosage regimens and alleviate the emergence of resistance. The semi-mechanistic PK/PD model is a mathematical quantitative tool to capture the relationship between dose, exposure, and response, in terms of the mechanism. Understanding the different resistant mechanisms of bacteria to various antibacterials and presenting this as mathematical equations, the semi-mechanistic PK/PD model can capture and simulate the progress of bacterial growth and the variation in susceptibility. In this review, we outline the bacterial growth model and antibacterial effect model, including different resistant mechanisms, such as persisting resistance, adaptive resistance, and pre-existing resistance, of antibacterials against bacteria. The application of the semi-mechanistic PK/PD model, such as the determination of PK/PD breakpoints, combination therapy, and dosage optimization, are also summarized. Additionally, it is important to integrate the PD effect, such as the inoculum effect and host response, in order to develop a comprehensive mechanism model. In conclusion, with the semi-mechanistic PK/PD model, the dosage regimen can be reasonably determined, which can suppress bacterial growth and resistance development.

Metabolite Identification and Pharmacokinetic Behavior of Diaveridine in the Plasma of Pigs and Chickens Based on Radioactive Tracing Coupled With LC/MS-IT-TOF Assay

Diaveridine (DVD) is widely used for the prevention and treatment of coccidiosis and leucocytozoonosis infections in food-producing animals. To gain a better understanding of DVD metabolism and pharmacokinetics in healthy Landrace/Doric Cross castrated male pigs and both female and male Cobb 500 broiler chickens, a method involving radioactive tracing coupled with LC/MS-IT-TOF was developed for the identification and quantitation of DVD and its metabolites in pig and chicken plasma, and then was applied to investigate DVD pharmacokinetics. A simple MCX solid phase extraction procedure was adopted for sample preparation. After a single oral administration of 3H-DVD (10 mg/kg BW), three radioactive compounds (D0: DVD; D1: 3'-desmethyl-DVD; and D2: monoglucuronide of 3'-desmethyl-DVD) were identified in pig plasma, while only two radioactive compounds (D0 and D2) were identified in chicken plasma. In both species, the C max values for all detected compounds were reached at 2 h after dosing. The C max order was D2 (1.38 μg/ml) > D0 (0.49 μg/ml) > D1 (0.24 μg/ml) in pigs and D0 (1.55 μg/ml) > D2 (0.27 μg/ml) in chickens. The longer t 1/2 (elimination half-life) of D0 contributed to the slow elimination of DVD-related compounds. The t 1/2β of D0 in pigs (66.41 h) was significantly longer than that in chickens (48.30 h), but the t 1/2 of total DVD-related metabolites in pigs (42.86 h) was lower than that in chickens (56.11 h). These findings suggested that the metabolism and pharmacokinetics of DVD in pigs and chickens were significantly different, and that this would affect its effectiveness, toxicology, and food safety in these animals.

In Vitro Metabolism of Helenalin Acetate and 11α,13-Dihydrohelenalin Acetate: Natural Sesquiterpene Lactones from Arnica

Arnica tincture is a herbal medicinal preparation with anti-inflammatory activity which is used traditionally for the topical treatment of blunt injuries as well as rheumatic muscle and joint complaints. Its main bioactive constituents are sesquiterpene lactones (STLs) of the helenalin and 11α,13-dihydrohelenalin types. Besides the mentioned activity, the tincture and its isolated STLs have antileishmanial activity. In a recent in vivo study, a treatment with Arnica tincture cured cutaneous Leishmaniasis (CL) in a golden hamster model. CL is a neglected tropical disease affecting more than two million people every year, for which new treatments are urgently needed. In order to use Arnica tincture on open CL lesions of human patients, it is important to know how the constituents are metabolized. Therefore, in vitro metabolism experiments with liver microsomes of different species (rat, pig and human) were performed with the Arnica STLs helenalin acetate and 11α,13-dihydrohelenalin acetate. Phase I and phase II metabolism experiments were performed, as well as a combination of both. Glutathione conjugation plays a major role in the metabolism of these STLs, as could be expected based on previous reports on their reactivity. Besides glutathione conjugates, several other metabolites were formed, e.g., water conjugates and hydroxides. Our results show for the first time a detailed picture of the metabolism of Arnica STLs. The fast and extensive formation of glutathione conjugates makes it unlikely that low absorbed levels of these compounds, as expected after dermal absorption from Arnica tincture, could be of toxicological concern.

Influence of release rate, dose and co-administration on pharmacokinetics, pharmacodynamics and PK-PD relationship of tanshinone IIA and tanshinol

The present study aims to investigate the influence of release rate, dose and co-administration on pharmacokinetics (PK) and pharmacodynamics (PD) of tanshinone IIA (TA) and tanshinol (TS), and reveal the changes in their PK-PD relationships. Sustained and immediate release pellets of TS and TA were prepared respectively, and oral administrated to angina model rabbits according to the experimental design. The administration dose of TS was 50, 35 or 20 mg/kg and that of TA was 30 mg/kg. Then, plasma concentrations of TS and TA were measured to evaluate the pharmacokinetics. Pharmacodynamic biomarkers including cardiac troponin (cTn-I), creatine kinase (CK-MB), superoxide dismutase (SOD) and nitric oxide (NO) were measured to evaluated the effects of cardioprotection, amelioration of oxidative stress and vasorelaxation of TS and TA. Parameters such as maximum plasma concentration (C_max), maximum effect (E_max), time to C_max or E_max (TC_max or TE_max), areas under the plasma concentration or effect curves (AUC_0-∞ or AUEC) and pharmacodynamic efficiency (EFF) were calculated based on non-compartmental analysis. Beside, PK-PD relationship/hysteresis was evaluated. The TE_max was less sensitive than TC_max to changes in release rate. The E_max, AUEC and EFF showed increasing trend as the decrease of release rate even that the AUC_0-∞ showed no significant difference. In addition, slow drug release decreased the magnitude of hysteresis of TS and TA. The sensitivities of E_max and AUEC of four biomarkers to changes in dose were varied and relatively lower than those of C_max and AUC_0-∞. The EFF decreased and the magnitude of hysteresis increased for high dose. The C_max and AUC_0-∞ of TS and TA showed little difference after co-administration. The E_max and AUEC of four biomarkers increased for immediate release pellets (P < 0.05 or P < 0.01) and generally decreased for sustained release pellets (P < 0.05 or P < 0.01) after co-administration. In addition, the magnitudes of hysteresis of four biomarkers decreased for immediate release pellets and generally increased for sustained release pellets after co-administration. In summary, the dissociated and unstable PK-PD relationship should be considered during optimization of dosage forms and regimens to make sure the rationality, safety and efficacy. These findings could also provide some valuable information for the development and clinical therapy of other drugs.

Advanced approaches for improving bioavailability and controlled release of anthocyanins

Anthocyanins are a group of phytochemicals responsible for the purple or red color of plants. Additionally, they are recognized to have health promoting functions including anti-cardiovascular, anti-thrombotic, anti-diabetic, antimicrobial, neuroprotective, and visual protective effect as well as anti-cancer activities. Thus, consumption of anthocyanin supplement or anthocyanin-rich foods has been recommended to prevent the risk of development of chronic diseases. However, the low stability and bioavailability of anthocyanins limit the efficacy and distribution of anthocyanins in human body. Thus, strategies to achieve target site-local delivery with good bioavailability and controlled release rate are necessary. This review introduced and discussed the latest advanced techniques of designing lipid-based, polysaccharide-based and protein-based complexes, nano-encapsulation and exosome to overcome the limitation of anthocyanins. The improved bioavailability and controlled release of anthocyanins have great significance for gastrointestinal tract absorption, transepithelial transportation and cellular uptake. The techniques of applying different biocompatible materials and modifying the solubility of anthocyanins complex could achieve target site-local delivery with negligible degradation and good bioavailability in human body.

PBPK Modeling and Simulation and Therapeutic Drug Monitoring: Possible Ways for Antibiotic Dose Adjustment

Pharmacokinetics (PK) is a branch of pharmacology present and of vital importance for the research and development (R&D) of new drugs, post-market monitoring, and continued optimizations in clinical contexts. Ultimately, pharmacokinetics can contribute to improving patients’ clinical outcomes, helping enhance the efficacy of treatments, and reducing possible adverse side effects while also contributing to precision medicine. This article discusses the methods used to predict and study human pharmacokinetics and their evolution to the current physiologically based pharmacokinetic (PBPK) modeling and simulation methods. The importance of therapeutic drug monitoring (TDM) and PBPK as valuable tools for Model-Informed Precision Dosing (MIPD) are highlighted, with particular emphasis on antibiotic therapy since dosage adjustment of antibiotics can be vital to ensure successful clinical outcomes and to prevent the spread of resistant bacterial strains.

Preclinical Pharmacokinetics and Acute Toxicity in Rats of 5-{[(2E)-3-Bromo-3-carboxyprop-2-enoyl]amino}-2-hydroxybenzoic Acid: A Novel 5-Aminosalicylic Acid Derivative with Potent Anti-Inflammatory Activity

Compound 5-{[(2E)-3-bromo-3-carboxyprop-2-enoyl]amino}-2-hydroxybenzoic acid (C1), a new 5-aminosalicylic acid (5-ASA) derivative, has proven to be an antioxidant in vitro and an anti-inflammatory agent in mice. The in vivo inhibition of myeloperoxidase was comparable to that of indomethacin. The aim of this study was to take another step in the preclinical evaluation of C1 by examining acute toxicity with the up-and-down OECD method and pharmacokinetic profiles by administration of the compound to Wistar rats through intravenous (i.v.), oral (p.o.), and intraperitoneal (i.p.) routes. According to the Globally Harmonized System, C1 belongs to categories 4 and 5 for the i.p. and p.o. routes, respectively. An RP-HPLC method for C1 quantification in plasma was successfully validated. Regarding the pharmacokinetic profile, the elimination half-life was approximately 0.9 h with a clearance of 24 mL/min after i.v. administration of C1 (50 mg/kg). After p.o. administration (50 mg/kg), the maximum plasma concentration was reached at 33 min, the oral bioavailability was about 77%, and the compound was amply distributed to all tissues evaluated. Therefore, C1 administered p.o. in rats is suitable for reaching the colon where it can exert its effect, suggesting an important advantage over 5-ASA and indomethacin in treating ulcerative colitis and Crohn’s disease.

Study of the Distribution of Acetaminophen and Its Metabolites in Rats, from the Whole-Body to Isolated Organ Levels, by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging after On-Tissue Chemical Derivatization

During drug development, detailed investigations of the pharmacokinetic profile of the drug are required to characterize its absorption, distribution, metabolism, and excretion properties. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is an established technique for studies of the distribution of drugs and their metabolites. It has advantages over autoradiography, which is conventionally used for distribution studies: it does not require the radiolabeling of drugs and can distinguish between the drug and its metabolites directly in the tissue. However, its lack of sensitivity in certain cases remains challenging. Novel procedures, such as on-tissue chemical derivatization (OTCD), could be developed to increase sensitivity. We used OTCD to enhance the sensitivity of MALDI-MSI for one of the most widely used drugs, acetaminophen, and to study its distribution in tissues. Without derivatization, this drug and some of its metabolites are undetectable by MALDI-MSI in the tissues of treated rats. We used 2-fluoro-1-methylpyridinium p-toluene sulfonate as a derivatization reagent, to increase the ionization yield of acetaminophen and some of its metabolites. The OTCD protocol made it possible to study the distribution of acetaminophen and its metabolites in whole-body sections at a spatial resolution of 400 μm and in complex anatomical structures, such as the testis and epididymis, at a spatial resolution <50 μm. The OTCD is also shown to be compatible with the quantification of acetaminophen by MALDI-MSI in whole-body tissues. This protocol could be applied to other molecules bearing phenol groups and presenting a low ionization efficiency.

Pharmacokinetic herb-drug interactions between Aidi injection and doxorubicin in rats with diethylnitrosamine-induced hepatocellular carcinoma

BACKGROUND

Aidi Injection (ADI), a Chinese herbal preparation with anti-cancer activity, is used for the treatment of hepatocellular carcinoma (HCC). Several clinical studies have shown that co-administration of ADI with doxorubicin (DOX) is associated with reduced toxicity of chemotherapy, enhanced clinical efficacy and improved quality of life for patients. However, limited information is available about the herb-drug interactions between ADI and DOX. The study aimed to investigate the pharmacokinetic mechanism of herb-drug interactions between ADI and DOX in a rat model of HCC.

METHODS

Experimental HCC was induced in rats by oral administration of diethylnitrosamine. The HCC rats were pretreated with ADI (10 mL/kg, intraperitoneal injection) for 14 consecutive days prior to administration of DOX (7 mg/kg, intravenous injection) to investigate pharmacokinetic interactions. Plasma concentrations of DOX and its major metabolite, doxorubicinol (DOXol), were determined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

RESULTS

Preadministration of ADI significantly altered the pharmacokinetics of DOX in HCC rats, leading to increased plasma concentrations of both DOX and DOXol. The area under the plasma drug concentration-time curve (AUCs) of DOX and DOXol in rats pretreated with ADI were 3.79-fold and 2.92-fold higher, respectively, than those in control rats that did not receive ADI.

CONCLUSIONS

Increased levels of DOX and DOXol were found in the plasma of HCC rats pretreated with ADI.

Ultra-high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry method for quantifying polymer poloxamer 124 and its application to pharmacokinetic study

Poloxamer is a commonly used pharmaceutical excipient. It is a high molecular polymer formed using polypropylene oxide and polyethylene oxide units. Specifically, poloxamer 124 is one of the smaller molecular weight in the poloxamer series; however, its pharmacokinetic behaviors in vivo are still unclear. In this study, a method for quantifying poloxamer 124 in rat plasma through ultra-high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry was developed. The intravenous dosage of PL124 was 10 mg/kg. Plasma was collected at different times. The calibration curve was linear in the range of 0.1-5 μg/mL for the poloxamer 124 (r ≥ 0.9956) with the lower limit of quantitation of 0.1 μg/ml. The relative standard deviation of the intraday and interday precisions was below 8.0%, and the relative error of the accuracy was within ±12.0%. The extraction recovery, matrix effect, and stability were satisfactory in rat plasma. The validated method was successfully applied to a pharmacokinetic study of poloxamer 124 in rats. Results indicated that poloxamer 124 could be rapidly absorbed and eliminated through caudal vein injection. This study is helpful for the further study of poloxamer 124.

Individualized precision dosing approaches to optimize antimicrobial therapy in pediatric populations

Introduction:Severe infections continue to impose a major burden on critically ill children and mortality rates remain stagnant. Outcomes rely on accurate and timely delivery of antimicrobials achieving target concentrations in infected tissue. Yet, developmental aspects, disease-related variables, and host factors may severely alter antimicrobial pharmacokinetics in pediatrics. The emergence of antimicrobial resistance increases the need for improved treatment approaches.Areas covered:This narrative review explores why optimization of antimicrobial therapy in neonates, infants, children, and adolescents is crucial and summarizes the possible dosing approaches to achieve antimicrobial individualization. Finally, we outline a roadmap toward scientific evidence informing the development and implementation of precision antimicrobial dosing in critically ill children.The literature search was conducted on PubMed using the following keywords: neonate, infant, child, adolescent, pediatrics, antimicrobial, pharmacokinetic, pharmacodynamic target, Bayes dosing software, optimizing, individualizing, personalizing, precision dosing, drug monitoring, validation, attainment, and software implementation. Further articles were sought from the references of the above searched articles.Expert opinion:Recently, technological innovations have emerged that enabled the development of individualized antimicrobial dosing approaches in adults. More work is required in pediatrics to make individualized antimicrobial dosing approaches widely operationalized in this population.

In Vivo Induction of P-Glycoprotein Function can be Measured with [18F]MC225 and PET

P-Glycoprotein (P-gp) is an efflux pump located at the blood-brain barrier (BBB) that contributes to the protection of the central nervous system by transporting neurotoxic compounds out of the brain. A decline in P-gp function has been related to the pathogenesis of neurodegenerative diseases. P-gp inducers can increase the P-gp function and are considered as potential candidates for the treatment of such disorders. The P-gp inducer MC111 increased P-gp expression and function in SW480 human colon adenocarcinoma and colo-320 cells, respectively. Our study aims to evaluate the P-gp inducing effect of MC111 in the whole brain in vivo, using the P-gp tracer [18F]MC225 and positron emission tomography (PET). Eighteen Wistar rats were treated with either vehicle solution, 4.5 mg/kg of MC111 (low-dose group), or 6 mg/kg of MC111 (high-dose group). Animals underwent a 60 min dynamic PET scan with arterial-blood sampling, 24 h after treatment with the inducer. Data were analyzed using the 1-tissue-compartment model and metabolite-corrected plasma as the input function. Model parameters such as the influx constant (K1) and volume of distribution (VT) were calculated, which reflect the in vivo P-gp function. P-gp and pregnane xenobiotic receptor (PXR) expression levels of the whole brain were assessed using western blot. The administration of MC111 decreased K1 and VT of [18F]MC225 in the whole brain and all of the selected brain regions. In the high-dose group, whole-brain K1 was decreased by 34% (K1-high-dose = 0.20 ± 0.02 vs K1-control = 0.30 ± 0.02; p < 0.001) and in the low-dose group by 7% (K1-low-dose = 0.28 ± 0.02 vs K1-control = 0.30 ± 0.02; p = 0.42) compared to controls. Whole-brain VT was decreased by 25% in the high-dose group (VT-high-dose = 5.92 ± 0.41 vs VT-control = 7.82 ± 0.38; p < 0.001) and by 6% in the low-dose group (VT-low-dose = 7.35 ± 0.38 vs VT-control = 7.82 ± 0.37; p = 0.38) compared to controls. k2 values did not vary after treatment. The treatment did not affect the metabolism of [18F]MC225. Western blot studies using the whole-brain tissue did not detect changes in the P-gp expression, however, preliminary results using isolated brain capillaries found an increasing trend up to 37% in treated rats. The decrease in K1 and VT values after treatment with the inducer indicates an increase in the P-gp functionality at the BBB of treated rats. Moreover, preliminary results using brain endothelial cells also sustained the increase in the P-gp expression. In conclusion, the results verify that MC111 induces P-gp expression and function at the BBB in rats. An increasing trend regarding the P-gp expression levels is found using western blot and an increased P-gp function is confirmed with [18F]MC225 and PET.

Bioanalysis of niclosamide in plasma using liquid chromatography-tandem mass and application to pharmacokinetics in rats and dogs

Niclosamide, which is an anti-tapeworm drug, was developed in 1958. However, recent studies have demonstrated the antiviral effects of niclosamide against the SARS-CoV-2 virus, which causes COVID-19. In this study, we developed and validated a quantitative analysis method for the determination of niclosamide in rat and dog plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and used this method for pharmacokinetic studies. Biological samples were prepared using the protein precipitation method with acetonitrile. Ibuprofen was used as an internal standard. The mobile phase used to quantify niclosamide in rat or dog plasma consisted of 10 mM ammonium formate in distilled water-acetonitrile (30:70, v/v) or 5 mM ammonium acetate-methanol (30:70, v/v). An XDB-phenyl column (5 µm, 2.1 × 50 mm) and a Kinetex® C18 column (5 µm, 2.1 × 500 mm) were used as reverse-phase liquid chromatography columns for rat and dog plasma analyses, respectively. Niclosamide and ibuprofen were detected under multiple reaction monitoring conditions using the electrospray ionization interface running in the negative ionization mode. Niclosamide presented linearity in the concentration ranges of 1-3000 ng/mL (r = 0.9967) and 1-1000 ng/mL (r = 0.9941) in rat and dog plasma, respectively. The intra- and inter-day precision values were < 7.40% and < 6.35%, respectively, for rat plasma, and < 3.95% and < 4.01%, respectively, for dog plasma. The intra- and inter-day accuracy values were < 4.59% and < 6.63%, respectively, for rat plasma, and < 12.1% and < 10.9%, respectively, for dog plasma. In addition, the recoveries of niclosamide ranged between 87.8 and 99.6% and 102-104% for rat and dog plasma, respectively. Niclosamide was stable during storage under various conditions (three freeze-thaw cycles, 6 h at room temperature, long-term, and processed samples). A reliable LC-MS/MS method for niclosamide detection was successfully used to perform pharmacokinetic studies in rats and dogs. Niclosamide presented dose-independent pharmacokinetics in the dose range of 0.3-3 mg/kg after intravenous administration, and drug exposure in rats and dogs after oral administration was very low. Additionally, niclosamide presented high plasma protein binding (>99.8%) and low metabolic stability. These results can be helpful for further developing and understanding the pharmacokinetic characteristics of niclosamide to expand its clinical use.

LXR-Mediated Regulation of Marine-Derived Piericidins Aggravates High-Cholesterol Diet-Induced Cholesterol Metabolism Disorder in Mice

Reported as two antirenal cell carcinoma (RCC) drug candidates, marine-derived compounds piericidin A (PA) and glucopiericidin A (GPA) exhibit hepatotoxicity in renal carcinoma xenograft mice. Proteomics and transcriptomics reveal the hepatotoxicity related with cholesterol disposition since RCC is characterized by cholesterol accumulation. PA/GPA aggravate hepatotoxicity in high-cholesterol diet (HCD)-fed mice while exhibiting no toxicity in chow diet-fed mice. High cholesterol accumulation in liver is liver X receptor (LXR)-mediated cytochrome P450 family 7 subfamily a member 1 (CYP7A1) depression and low-density lipoprotein receptor (LDLR) activation. The farnesoid X nuclear receptor (FXR) is also depressed with a downregulated target gene OSTα. Different from PA directly combined with LXRα as an inhibitor, GPA exists as a prodrug in the liver and exerts toxic effects due to transformation into PA. Surface plasmon resonance (SPR) and docking results of 17 piericidins illustrate that glycosides exert no LXRα binding activity. A longer survival time of GPA-treated mice indicates that further exploration in anti-RCC drug research should focus on reducing glycosides transformed into PA and concentrating in the kidney tumor rather than the liver for lowering the risk of hepatotoxicity.

Acute toxicity, antinociceptive, and anti-inflammatory activities of the orally administered crotamine in mice

Crotamine is a polypeptide toxin isolated from rattlesnake venom. Although several studies have been developed identifying many biological effects of isolated crotamine, none of them evaluated its acute toxicity, antinociceptive, and anti-inflammatory activities through oral administration. All in vivo experiments from this study were performed in mice. The up-and-down procedure and hippocratic screening were carried out to evaluate possible pharmacological and toxic effects. Antinociceptive and anti-inflammatory activities of this toxin were evaluated using acetic acid-induced abdominal writhing, formalin-induced pain assays, croton oil-induced ear edema, and carrageenan-induced pleurisy. Crotamine did not cause lethality or signs of intoxication up to the maximum dose tested (10.88 mg/kg). The number of contortions was reduced significantly by 34, 57, and 74% at the oral doses of 0.08, 0.16, and 0.32 mg/kg, respectively. At the dose of 0.16 mg/kg, crotamine decreases pain time-reactivity at neurogenic phase by 45% and at inflammatory phase by 60%. Also, crotamine elicited antiedematogenic activity through the attenuation of the croton oil-induced ear edema by 77%. In the carrageenan-induced pleurisy, the leukocyte, neutrophil, and mononuclear cell migration to the lesion site were reduced by 52%, 46%, and 59%, respectively. Altogether, crotamine demonstrated in vivo antinociceptive and anti-inflammatory effect through acute oral administration, generating an anti-migratory mechanism of action at non-toxic doses.

Boronate Affinity-Based Oriented and Double-Shelled Surface Molecularly Imprinted Polymers on 96-Well Microplates for a High-Throughput Pharmacokinetic Study of Rutin and Its Metabolites

The boronate affinity-based oriented and double-shelled surface molecularly imprinted polymers on 96-well microplates (BDMIPs) were designed and applied to high-specific and high-throughput pharmacokinetic (PK) study of rutin and its metabolites from rat plasma without concentration and redissolution. It integrated the advantages of covalent effects-based boronate affinity, noncovalent effects of ethylene imine polymer (PEI) dendrimer, multiple cavities-based double-shelled layers, and multiparallel wells-based 96-well microplates. Furthermore, ultrahigh-performance liquid chromatography triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) was used to accurately quantify targets. It showed lower limits of detection (LODs) up to 100-fold than the conventional method. And PKs of rutin and trace isoquercetin (IQC) were first reported at the same time. The platform can provide a fast, simple, low-cost, high-selective, high-effective, and high-throughput methodological reference for analysis of large-scale samples in the fields of agriculture and food.

A meta-analysis of bone cement mediated antibiotic release: Overkill, but a viable approach to eradicate osteomyelitis and other infections tied to open procedures

A number of clinical studies have highlighted the success of antibiotics formulated at concentrations between 0 and 6% w/w into bone cements to address localized infections. Separately, some commercial manufacturers have produced gentamycin-infused bone cement mixtures as a countermeasure to infection. The anecdotal evidence suggests that antibiotic infused cements can help eradicate or delay the onset of infections. Quantifying the functionality of that response is more challenging. We have surveyed the literature to identify studies in which controlled drug release or mechanical behavioral assessments have been conducted on drug-infused cements. The focus here is on vancomycin (VAN) in part due to its higher potency relative to gentamycin and its more common usage for staph infections. Takeaways from the limited pool of research studies indicate that large fractions (>99%) of the infused vancomycin remain sequestered in the cement and aren't bioavailable after solidification. Antibiotic fluence ranged from 1 to 283 μg/cm²hr. The initial strength of the various antibiotic loaded samples as produced were 52-96 MPa. Simulated exposures in a fluid environment by submersion reduced the antibiotic loaded strengths between 3 and 29%. Some strength measurements were noted below the ASTM F451 standard for acrylic bone cement although drug releasing spacers likely have different requirements. The glassy behavior of the cured cement led to both vancomycin and gentamicin having low permeability and a burst response. Smaller drug molecules and more gel-like immobilization matrices with lower glass transition temperatures offer higher potential for larger and more comprehensive drug bioavailability.

Preparation of intravenous chemotherapy bags: evaluation of a dose banding approach in an Italian oncology hospital

Introduction

Dose banding is an original approach that manages intravenous (IV) chemotherapy preparation by generating on a weekly basis a series of bags containing scaled dosages of the active agent. These predetermined, fixed dosage bags are intended to replace the traditional bags prepared daily that contain fully individualized dosages.

Methods

Three different scenarios were examined: (1) the current method of daily preparation of individualized bags at the hospital pharmacy; (2) the weekly preparation at the hospital pharmacy of non-individualized bags containing discrete, predefined doses covering an adequate range of doses (dose banding); (3) the use of commercial ready-to-use bags based on the same approach of dose banding. The objective of this study was to compare these three different approaches in terms of cost per patient. We considered five cancer drugs (gemcitabine, oxaliplatin, paclitaxel, trastuzumab and 5-fluorouracil) that were suitable for the dose ranging approach. Appropriate dose bands for these five agents were identified. Costs were estimated for each of the three approaches.

Results

A total of 13,490 fully individualized bags were studied, which corresponded to the real bags prepared at our institution for these five agents in 2018. Dose banding was predicted to determine savings ranging from €10,998 (-0.84%) for trastuzumab to €169,429.60 (-8.39%) for paclitaxel.

Conclusion

The introduction of dose banding can determine economic savings along with other advantages, such as improved work conditions, management reorganization and containment of waste. The pharmaceutical industry can hopefully support these experiences by producing ready-to-use bags in predetermined dosages.

Glossary and tutorial of xenobiotic metabolism terms used during small molecule drug discovery and development (IUPAC Technical Report)

This project originated more than 15 years ago with the intent to produce a glossary of drug metabolism terms having definitions especially applicable for use by practicing medicinal chemists. A first-draft version underwent extensive beta-testing that, fortuitously, engaged international audiences in a wide range of disciplines involved in drug discovery and development. It became clear that the inclusion of information to enhance discussions among this mix of participants would be even more valuable. The present version retains a chemical structure theme while expanding tutorial comments that aim to bridge the various perspectives that may arise during interdisciplinary communications about a given term. This glossary is intended to be educational for early stage researchers, as well as useful for investigators at various levels who participate on today’s highly multidisciplinary, collaborative small molecule drug discovery teams.

On the search for COVID-19 therapeutics: identification of potential SARS-CoV-2 main protease inhibitors by virtual screening, pharmacophore modeling and molecular dynamics

COVID-19 also known as SARS-CoV-2 outbreak in late 2019 and its worldwide pandemic spread has taken the world by surprise. The minute-to-minute increasing coronavirus cases (>85 M) and progressive deaths (≈1.8 M) calls for finding a cure to this devastating pandemic. While there have been many attempts to find biologically active molecules targeting SARS-CoV-2 for treatment of this viral infection, none has found a way to the clinic yet. In this study, a 3-feature structure-based pharmacophore model was designed for SARS-CoV-2 main protease (M^Pro) that plays a vital role in the viral cellular penetration. High throughput virtual screening of the lead-like ZINC library was then performed to find a potent inhibitor employing the predesigned pharmacophore. In-silico pharmacokinetics/toxicity prediction study was subsequently applied towards the best hits. Finally, a 50 ns molecular dynamics simulation was carried out for the best hit and compared to the co-crystallized ligand where the hit compound displayed high binding and comparable interactions. The results identified new hits for SARS-CoV-2 M^Pro inhibition showing good docking score, pharmacokinetics and toxicity profile, drug-likeness, high binding energy in addition to a promising synthetic accessibility. Identifying new small compounds as potential leads for inhibiting SARS-CoV-2 is a very important step towards designing a synthesizing of promising drug candidates.Communicated by Ramaswamy H. Sarma.

High-Sensitivity Permeation Analysis of Ultrasmall Nanoparticles Across the Skin by Positron Emission Tomography

Ultrasmall nanoparticles (US-NPs; <20 nm in hydrodynamic size) are now included in a variety of pharmacological and cosmetic products, and new technologies are needed to detect at high sensitivity the passage of small doses of these products across biological barriers such as the skin. In this work, a diffusion cell adapted to positron emission tomography (PET), a highly sensitive imaging technology, was developed to measure the passage of gold NPs (AuNPs) in skin samples in continuous mode. US-AuNPs (3.2 nm diam.; TEM) were functionalized with deferoxamine (DFO) and radiolabeled with ⁸⁹Zr_(IV) (half-life: 3.3 days, matching the timeline of diffusion tests). The physicochemical properties of the functionalized US-AuNPs (US-AuNPs-PEG-DFO) were characterized by FTIR (DFO grafting; hydroxamate peaks: 1629.0 cm^-1, 1569.0 cm^-1), XPS (presence of the O═C-N C 1s peak of DFO at 287.49 eV), and TGA (organic mass fraction). The passage of US-AuNPs-PEG-DFO-⁸⁹Zr_(IV) in skin samples was measured by PET, and the diffusion parameters were extracted thereby. The signals of radioactive US-AuNPs-PEG-DFO-⁸⁹Zr_(IV) leaving the donor compartment, passing through the skin, and entering the acceptor compartment were detected in continuous at concentrations as low as 2.2 nM of Au. The high-sensitivity acquisitions performed in continuous allowed for the first time to extract the lag time to the start of permeation, the lag time to start of the steady state, the diffusion coefficients, and the influx data for AuNPs permeating into the skin. PET could represent a highly valuable tool for the development of nanoparticle-containing topical formulations of drugs and cosmetics.

Directly Compressed Tablets: A Novel Drug-Containing Reservoir Combined with Hydrogel-Forming Microneedle Arrays for Transdermal Drug Delivery

Microneedle (MN) patches consist of a hydrogel-forming MN array and a drug-containing reservoir. Drug-containing reservoirs documented in the literature include polymeric films and lyophilized wafers. While effective, both reservoir formulations are aqueous based, and so degradation can occur during formulation and drying for drugs inherently unstable in aqueous media. The preparation and characterization of novel, nonaqueous-based, directly compressed tablets (DCTs) for use in combination with hydrogel-forming MN arrays are described for the first time. In this work, a range of drug molecules are investigated. Precipitation of amoxicillin (AMX) and primaquine (PQ) in conventional hydrogel-forming MN arrays leads to use of poly(vinyl alcohol)-based MN arrays. Following in vitro permeation studies, in vivo pharmacokinetic studies are conducted in rats with MN patches containing AMX, levodopa/carbidopa (LD/CD), and levofloxacin (LVX). Therapeutically relevant concentrations of AMX (≥2 µg mL^-1 ), LD (≥0.5 µg mL^-1 ), and LVX (≥0.2 µg mL^-1 ) are successfully achieved at 1, 2, and 1 h, respectively. Thus, the use of DCTs offers promise to expand the range of drug molecules that can be delivered transdermally using MN patches.

Toxic Prediction of Pyrrolizidine Alkaloids and Structure-Dependent Induction of Apoptosis in HepaRG Cells

Pyrrolizidine alkaloids (PAs) are common phytotoxins and could cause liver genotoxicity/carcinogenicity following metabolic activation. However, the toxicity of different structures remains unclear due to the wide variety of PAs. In this study, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) of 40 PAs were analyzed, and their toxicity was predicted by Komputer Assisted Technology (TOPKAT) using Discovery Studio software. The in silico results showed that all PAs except retronecine had good intestinal absorption, and all PAs were predicted to have different toxicity ranges. To verify the predictive results, 4 PAs were selected to investigate cell injury and possible mechanisms of the differentiation in HepaRG cells, including retronecine type of twelve-membered cyclic diester (retrorsine), eleven-membered cyclic diester (monocrotaline), noncyclic diester (retronecine), and platynecine type (platyphylline). After 24 h exposure, retronecine-type PAs exhibited concentration-dependent cytotoxicity. The high-content screening assay showed that cell oxidative stress, mitochondrial damage, endoplasmic reticulum stress, and the concentration of calcium ions increased, and neutral lipid metabolism was changed notably in HepaRG cells. Induced apoptosis by PAs was indicated by cell cycle arrest in the G2/M phase, disrupting the mitochondrial membrane potential. Overall, our study revealed structure-dependent cytotoxicity and apoptosis after PA exposure, suggesting that the prediction results of in silico have certain reference values for compound toxicity. A 1,2-membered cyclic diester seems to be a more potent apoptosis inducer than other PAs.

Preclinical Pharmacokinetics, Tissue Distribution and Primary Safety Evaluation of a Novel Curcumin Analogue H10 Suspension, a Potential 17β Hydroxysteroid Dehydrogenase Type 3 Inhibitor

17β Hydroxysteroid dehydrogenase type 3 (17β-HSD3) is the key enzyme in the biosynthesis of testosterone, which is an attractive therapeutic target for prostate cancer (PCa). H10, a novel curcumin analogue, was identified as a potential 17β-HSD3 inhibitor. The pharmacokinetic study of H10 in rats were performed by intraperitoneal (i.p.), intravenous (i.v.) and oral (p.o.) administration. In addition, the inhibitory effects of H10 against liver CYP3A4 were investigated in vitro using human liver microsomes (HLMs). The acute and chronic toxicological characteristics were characterized using single-dose and 30 d administration. All the mice were alive after i.p. H10 with dose of no more than 100 mg/kg which are nearly the maximum solubility in acute toxicity test. The pharmacokinetic characteristics of H10 fitted with linear dynamics model after single dose. Furthermore, H10 could bioaccumulate in testis, which was the target organ of 17β-HSD3 inhibitor. H10 distributed highest in spleen, and then in liver both after single and multiple i.p. administration. Moreover, H10 showed weak inhibition towards liver CYP3A4, and did not cause significant changes in aspartate transaminase (AST) and alanine transaminase (ALT) levels after treated with H10 for continuously 30 d. Taken together, these preclinical characteristics laid the foundation for further clinical studies of H10.

Pharmacokinetic Characteristics of Long-Acting Injectable Antipsychotics for Schizophrenia: An Overview

The availability of long-acting injectable (LAI) antipsychotics for the treatment of schizophrenia provides clinicians with options that deliver continuous drug exposure and may improve adherence compared with daily oral antipsychotics. However, all LAI antipsychotics have unique formulations and pharmacokinetic characteristics that have implications for medication selection, administration interval, and injection site. This review outlines key differences in drug formulations and pharmacokinetics among LAI antipsychotics. A systematic search of the PubMed database was conducted to identify physical and formulation properties and pharmacokinetic data of commercially available LAI antipsychotics, including flupentixol decanoate, fluphenazine decanoate, haloperidol decanoate, zuclopenthixol decanoate, aripiprazole monohydrate, aripiprazole lauroxil, olanzapine pamoate, paliperidone palmitate, risperidone microspheres, and risperidone polymeric microspheres. Additional information was obtained from package inserts and product monographs. Relevant data on drug properties, administration details, pharmacokinetic parameters, and oral dose equivalencies of LAI antipsychotics are summarized. Based on our analysis, formulation characteristics (e.g., vehicle medium) and administration characteristics (e.g., injection site) can affect rate of absorption and adverse effects and may factor into whether oral supplementation or an additional injection is needed. Dose adjustments may be necessary based on potential drug-drug interactions, and approximate dose equivalence with oral formulations can help inform titration when switching from oral to LAI formulations. Clinicians administering LAI antipsychotics should consider these formulation and pharmacokinetic factors to maximize clinical impact and to adjust to an individual patient's needs and treatment goals.

Pharmacokinetic Modeling of (R)-[11C]verapamil to Measure the P-Glycoprotein Function in Nonhuman Primates

(R)-[¹¹C]verapamil is a radiotracer widely used for the evaluation of the P-glycoprotein (P-gp) function at the blood–brain barrier (BBB). Several studies have evaluated the pharmacokinetics of (R)-[¹¹C]verapamil in rats and humans under different conditions. However, to the best of our knowledge, the pharmacokinetics of (R)-[¹¹C]verapamil have not yet been evaluated in nonhuman primates. Our study aims to establish (R)-[¹¹C]verapamil as a reference P-gp tracer for comparison of a newly developed P-gp positron emission tomography (PET) tracer in a species close to humans. Therefore, the study assesses the kinetics of (R)-[¹¹C]verapamil and evaluates the effect of scan duration and P-gp inhibition on estimated pharmacokinetic parameters. Three nonhuman primates underwent two dynamic 91 min PET scans with arterial blood sampling, one at baseline and another after inhibition of the P-gp function. The (R)-[¹¹C]verapamil data were analyzed using 1-tissue compartment model (1-TCM) and 2-tissue compartment model fits using plasma-corrected for polar radio-metabolites or non-corrected for radio-metabolites as an input function and with various scan durations (10, 20, 30, 60, and 91 min). The preferred model was chosen according to the Akaike information criterion and the standard errors (SE %) of the estimated parameters. 1-TCM was selected as the model of choice to analyze the (R)-[¹¹C]verapamil data at baseline and after inhibition and for all scan durations tested. The volume of distribution (V_T) and the efflux constant k₂ estimations were affected by the evaluated scan durations, whereas the influx constant K₁ estimations remained relatively constant. After P-gp inhibition (tariquidar, 8 mg/kg), in a 91 min scan duration, the whole-brain V_T increased significantly up to 208% (p < 0.001) and K₁ up to 159% (p < 0.001) compared with baseline scans. The k₂ values decreased significantly after P-gp inhibition in all the scan durations except for the 91 min scans. This study suggests the use of K₁, calculated with 1-TCM and using short PET scans (10 to 30 min), as a suitable parameter to measure the P-gp function at the BBB of nonhuman primates.

Microencapsulation of Coenzyme Q10 and bile acids using ionic gelation vibrational jet flow technology for oral delivery

Developing new delivery dosage forms with robust delivery and safety profiles remains a challenge to the pharmaceutical industry in terms of optimum gut absorption, consistent dosing and bioavailability; particularly for orally administered drugs that are poorly water soluble. Coenzyme Q10 is an example of a poorly water-soluble compound with low bioavailability, and significant inter-individual variation after oral administration; limiting its optimum efficacy, as a powerful antioxidant with significant promise in treating hearing disorders. Microencapsulation technology is one way to optimize drug bioavailability and absorption profile. One example is Ionic Gelation Vibrational Jet Flow techniques, using new encapsulating parameters to determine the nature of formed capsules. Bile acids are an example of an excipient that can be used to improve membrane permeability; and will be examined. This review addresses the applications of microencapsulation technology on oral delivery and efficacy profiles of poorly water-soluble drugs, focusing on Coenzyme Q10.

Food-Effect on (-) - Hydroxycitric Acid Absorption After Oral Administration of Garcinia cambogia Extract Formulation: a Phase I, Randomized, Cross-Over Study

Garcinia cambogia extract (GCE)/(-) - hydroxycitric acid (HCA) has been identified as a potential antiobesity agent. However, controversial clinical trial results have been published on its biological effect and poor pharmacokinetic (PK) information increases its dubious efficacy. The aim of this study was to determine the main PK parameters of GCE/HCA in healthy women, and to evaluate food effects on HCA absorption. Healthy women ages 21-41 years with body mass index (BMI; kg/m²) 20.29-25.82 participated in a phase I, open-label, randomized, single-dose, cross-over study. In the fasted- and fed-conditions subjects received 1500/750 mg of GCE/HCA under 8 h of fasting. In the fed-period was given a high calorie breakfast (~600 calories) after dosing. Plasma HCA concentrations were substantially reduced in fed-state. Peak plasma concentration (C_max) and area under the curve of time-concentration (AUC_0-10h) were 3-fold and 2-fold lower (p < 0.001, 0.01) in fed-condition, respectively. Higher volume of distribution (Vd/F) and clearance (Cl/F) were achieved in fed state, probably due to the lower fraction (F) of HCA absorbed induced by food effect. Large inter-individual variations were observed for the main pharmacokinetics parameters in both periods. These findings suggest that HCA might suffer an active absorption uptake and intense adsorption on food.

The Current Application of LC-MS/MS in Pharmacokinetics of Traditional Chinese Medicines (Recent Three Years): A Systematic Review

BACKGROUND

With significant clinical effects, traditional Chinese medicine (TCM) has been attracting increasing interest of the world's scientific community. However, TCM contains immense amounts of chemical components. It is a great challenge to objectively evaluate the correlation between the in vivo process and the therapeutic effect of TCM. The purpose of this systematic review was to summarize the recent investigation (from 2017 to 2019) on preclinical pharmacokinetics (PK) of TCM via liquid chromatography coupled with mass spectrometry (LC-MS/MS).

METHODS

We reviewed the published articles regarding the PK of TCM by LC-MS/MS. In addition, we summarized information on PK parameter of bioactive components, single herb and traditional Chinese medicine prescriptions.

RESULTS

The vast majority of literature on preclinical PK of TCM uses single oral administration, the biological matrix is mostly rat plasma, and the main PK parameters include AUC, Cmax, Tmax and T1/2, etc. Conclusion: Although LC-MS/MS can be used for high-throughput analysis, the characterization of in vivo processes of TCM still has a long way. With the advantages of high sensitivity, high specificity and simple operation, the increasingly mature LC-MS/MS technology will play an important role in the PK study of TCM.

Pharmacokinetics and bioavailability of ipatasertib in dog plasma using LC/MS/MS

A rapid, sensitive, and reliable liquid chromatography-tandem mass spectrometric method was developed to quantify ipatasertib in dog plasma. The dog plasma sample was deproteinated by using acetonitrile with ulixertinib as an internal standard followed by separation on a Spursil C₁₈ -EP column with a gradient mobile phase comprising 2 mM ammonium acetate containing 0.1% formic acid and acetonitrile. Positive ion electrospray was used, and multiple reaction monitoring transitions were m/z 458.2 > 387.2 for ipatasertib and m/z 433.1 > 262.1 for the internal standard. The developed method was validated with a linear range of 0.3-1500 ng/mL, and with correlation coefficient greater than 0.9989. The lower limit of quantification was 0.3 ng/mL. The intra- and inter-day precision ranged from 3.58 to 14.32%, whereas the intra- and inter-day accuracy was in the range of -2.50-13.25%. No carry-over and matrix effects were observed under the current conditions. The extraction recovery was demonstrated to be greater than 85.43%. Ipatasertib was stable during the storage, processing, and determination. The validated assay was further successfully applied to a pharmacokinetic study of ipatasertib in dogs after oral and intravenous administrations. The bioavailability of ipatasertib was determined to be 19.3%.

Microengineered systems with iPSC-derived cardiac and hepatic cells to evaluate drug adverse effects

Hepatic and cardiac drug adverse effects are among the leading causes of attrition in drug development programs, in part due to predictive failures of current animal or in vitro models. Hepatocytes and cardiomyocytes differentiated from human induced pluripotent stem cells (iPSCs) hold promise for predicting clinical drug effects, given their human-specific properties and their ability to harbor genetically determined characteristics that underlie inter-individual variations in drug response. Currently, the fetal-like properties and heterogeneity of hepatocytes and cardiomyocytes differentiated from iPSCs make them physiologically different from their counterparts isolated from primary tissues and limit their use for predicting clinical drug effects. To address this hurdle, there have been ongoing advances in differentiation and maturation protocols to improve the quality and use of iPSC-differentiated lineages. Among these are in vitro hepatic and cardiac cellular microsystems that can further enhance the physiology of cultured cells, can be used to better predict drug adverse effects, and investigate drug metabolism, pharmacokinetics, and pharmacodynamics to facilitate successful drug development. In this article, we discuss how cellular microsystems can establish microenvironments for these applications and propose how they could be used for potentially controlling the differentiation of hepatocytes or cardiomyocytes. The physiological relevance of cells is enhanced in cellular microsystems by simulating properties of tissue microenvironments, such as structural dimensionality, media flow, microfluidic control of media composition, and co-cultures with interacting cell types. Recent studies demonstrated that these properties also affect iPSC differentiations and we further elaborate on how they could control differentiation efficiency in microengineered devices. In summary, we describe recent advances in the field of cellular microsystems that can control the differentiation and maturation of hepatocytes and cardiomyocytes for drug evaluation. We also propose how future research with iPSCs within engineered microenvironments could enable their differentiation for scalable evaluations of drug effects.

Approaching sites of action of drugs in clinical pharmacology: New analytical options and their challenges

Clinical pharmacology is an important discipline for drug development aiming to define pharmacokinetics (PK), pharmacodynamics (PD) and optimum exposure to drugs, i.e. the concentration-response relationship and its modulators. For this purpose, information on drug concentrations at the anatomical, cellular and molecular sites of action is particularly valuable. In pharmacological assays, the limited accessibility of target cells in readily available samples (i.e. blood) often hampers mass spectrometry-based monitoring of the absolute quantity of a compound and the determination of its molecular action at the cellular level. Recently, new sample collection methods have been developed for the specific capture of rare circulating cells, especially for the diagnosis of circulating tumour cells. In parallel, new advances and developments in mass spectrometric instrumentation now allow analyses to be scaled down to the cellular level. Together, these developments may permit the monitoring of minute drug quantities and show their effect at the cellular level. In turn, such PK/PD associations on a cellular level would not only enrich our pharmacological knowledge of a given compound but also expand the basis for PK/PD simulations. In this review, we describe novel concepts supporting clinical pharmacology at the anatomical, cellular and molecular sites of action, and highlight the new challenges in mass spectrometry-based monitoring. Moreover, we present methods to tackle these challenges and define future needs.

Computational Approaches in Preclinical Studies on Drug Discovery and Development

Because undesirable pharmacokinetics and toxicity are significant reasons for the failure of drug development in the costly late stage, it has been widely recognized that drug ADMET properties should be considered as early as possible to reduce failure rates in the clinical phase of drug discovery. Concurrently, drug recalls have become increasingly common in recent years, prompting pharmaceutical companies to increase attention toward the safety evaluation of preclinical drugs. In vitro and in vivo drug evaluation techniques are currently more mature in preclinical applications, but these technologies are costly. In recent years, with the rapid development of computer science, in silico technology has been widely used to evaluate the relevant properties of drugs in the preclinical stage and has produced many software programs and in silico models, further promoting the study of ADMET in vitro. In this review, we first introduce the two ADMET prediction categories (molecular modeling and data modeling). Then, we perform a systematic classification and description of the databases and software commonly used for ADMET prediction. We focus on some widely studied ADMT properties as well as PBPK simulation, and we list some applications that are related to the prediction categories and web tools. Finally, we discuss challenges and limitations in the preclinical area and propose some suggestions and prospects for the future.

A validated LC-MS/MS method for the determination of RAF inhibitor LXH254: Application to pharmacokinetic study in rat

In this study, a simple and sensitive UHPLC-ESI-MS/MS method was established for the determination of LXH254 in rat plasma. The developed method was validated according to the Food and Drug administration guidelines. After extraction using ethyl acetate, the sample was separated on an ACQUITY BEH C₁₈ column. The mobile phase consisted of 2 mM ammonium acetate containing 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. The flow rate was 0.3 mL/min. A TSQ triple quadrupole mass spectrometer operated in positive-ion mode was used for mass detection, with multiple reaction monitoring transitions of m/z 503.3 > 459.1 and m/z 435.3 > 367.1 for LXH254 and olaparib (internal standard), respectively. An excellent linearity was achieved in the concentration range of 0.1-1000 ng/mL, with correlation coefficient >0.998. The mean recovery was more than 78.55%. Inter- and intra-day precision (percentage of relative standard deviation) did not exceed 12.87%, and accuracy was in the range of -2.50 to 13.50%. LXH254 was demonstrated to be stable under the tested storage conditions. The validated UHPLC-MS/MS method was further applied to the pharmacokinetic study of LXH254 in rat plasma after oral (2, 5, and 15 mg/kg) and intravenous (2 mg/kg) administrations. The pharmacokinetic study revealed that LXH254 showed low clearance, moderate bioavailability (~30%), and linear pharmacokinetic profile over the oral dose range of 2-15 mg/kg. To the best of our knowledge, this is the first report on the method development and validation of the determination of LXH254 and its application to pharmacokinetic study.

Pharmacokinetic Modeling of [18F]MC225 for Quantification of the P-Glycoprotein Function at the Blood-Brain Barrier in Non-Human Primates with PET

[¹⁸F]MC225 has been developed as a weak substrate of P-glycoprotein (P-gp) aimed to measure changes in the P-gp function at the blood–brain barrier with positron emission tomography. This study evaluates [¹⁸F]MC225 kinetics in non-human primates and investigates the effect of both scan duration and P-gp inhibition. Three rhesus monkeys underwent two 91-min dynamic scans with blood sampling at baseline and after P-gp inhibition (8 mg/kg tariquidar). Data were analyzed using the 1-tissue compartment model (1-TCM) and 2-tissue compartment model (2-TCM) fits using metabolite-corrected plasma as the input function and for various scan durations (10, 20, 30, 60, and 91 min). The preferred model was chosen according to the Akaike information criterion and the standard errors (%) of the estimated parameters. For the 91-min scan duration, the influx constant K₁ increased by 40.7% and the volume of distribution (V_T) by 30.4% after P-gp inhibition, while the efflux constant k₂ did not change significantly. Similar changes were found for all evaluated scan durations. K₁ did not depend on scan duration (10 min—K₁ = 0.2191 vs 91 min—K₁ = 0.2258), while V_T and k₂ did. A scan duration of 10 min seems sufficient to properly evaluate the P-gp function using K₁ obtained with 1-TCM. For the 91-min scan, V_T and K₁ can be estimated with a 2-TCM, and both parameters can be used to assess P-gp function.

The Pharmacogenetics of Efavirenz Metabolism in Children: The Potential Genetic and Medical Contributions to Child Development in the Context of Long-Term ARV Treatment

Efavirenz (EFV) is a well-known, effective anti-retroviral drug long used in first-line treatment for children and adults with HIV and HIV/AIDS. Due to its narrow window of effective concentrations, between 1 and 4 μg/mL, and neurological side effects at supratherapeutic levels, several investigations into the pharmacokinetics of the drug and its genetic underpinnings have been carried out, primarily with adult samples. A number of studies, however, have examined the genetic influences on the metabolism of EFV in children. Their primary goal has been to shed light on issues of appropriate pediatric dosing, as well as the manifestation of neurotoxic effects of EFV in some children. Although EFV is currently being phased out of use for the treatment of both adults and children, we share this line of research to highlight an important aspect of medical treatment that is relevant to understanding the development of children diagnosed with HIV.

Randomized, Parallel Group, Open-Label Bioequivalence Trial of Intramuscular Pegaspargase in Patients With Relapsed Acute Lymphoblastic Leukemia

PURPOSE

Pegylated asparaginase is comparatively safer than native asparaginase in the management of acute lymphoblastic leukemia (ALL). However, the high price and nonavailability in low- and middle-income countries limits its use. In 2014, the first generic of pegaspargase (Hamsyl) was approved in India for use as a second-line treatment option for ALL. The aim of this study was to assess whether the generic pegaspargase (the test product) was bioequivalent with the reference product (Oncaspar).

PATIENTS AND METHODS

This study was an open-label, parallel-group, comparative pharmacokinetic study in pediatric patients with relapsed ALL receiving their first dose (1,000 IU/m²) of pegaspargase administered intramuscularly. Patients were randomly assigned 1-to-1 to either the test or the reference product. The 2 formulations were considered equivalent if the 90% CIs for area under the plasma asparaginase activity–time curve (AUC_0-t) geometric mean test-to-reference ratio was within 75% to 133%.

RESULTS

Twenty-nine patients (6-18 years of age) were enrolled in this study, of whom 24 completed the study criteria and were considered for safety analysis (5 patients were ineligible for the assessment). Three patients were excluded from analysis, because of presence of anti-asparaginase antibodies, leaving 21 patients who were considered for bioequivalence pharmacokinetics data. The point estimate of AUC_0-t for the test-to-reference ratio was 95.05 (90% CI, 75.07% to 120.33%). Maximum plasma concentration, trough concentrations (day 14), half-life, volume of distribution, drug clearance, and changes in the asparagine and glutamine levels were not significantly different between products. Adverse events were comparable in both groups.

CONCLUSION

Generic and reference pegaspargase had equivalent pharmacokinetics with comparable safety. This could be a safe and cost-effective alternative for patients with ALL, especially in low- and middle-income countries.

Blood circulation of soft nanomaterials is governed by dynamic remodeling of protein opsonins at nano-biointerface

Nanomaterials in the blood must mitigate the immune response to have a prolonged vascular residency in vivo. The composition of the protein corona that forms at the nano-biointerface may be directing this, however, the possible correlation of corona composition with blood residency is currently unknown. Here‚ we report a panel of new soft single molecule polymer nanomaterials (SMPNs) with varying circulation times in mice (t_1/2β ~ 22 to 65 h) and use proteomics to probe protein corona at the nano-biointerface to elucidate the mechanism of blood residency of nanomaterials. The composition of the protein opsonins on SMPNs is qualitatively and quantitatively dynamic with time in circulation. SMPNs that circulate longer are able to clear some of the initial surface-bound common opsonins, including immunoglobulins, complement, and coagulation proteins. This continuous remodelling of protein opsonins may be an important decisive step in directing elimination or residence of soft nanomaterials in vivo.

The blood circulation time is important to the biomedical application of nanomaterials. Here, the authors explore the effect of protein corona formation on the blood residency of nanomaterials and show circulation times are governed by the dynamic remodelling of protein opsonins in vivo.

Role of PTA in the prevention of Cu(amyloid-β) induced ROS formation and amyloid-β oligomerisation in the presence of Zn

Metal-targeting drugs are being widely explored as a possible treatment for Alzheimer's disease, but most of these ligands are developed to coordinate Cu(ii). In a previous communication (E. Atrián-Blasco, E. Cerrada, A. Conte-Daban, D. Testemale, P. Faller, M. Laguna and C. Hureau, Metallomics, 2015, 7, 1229-1232) we showed another strategy where Cu(i) was targeted with the PTA (1,3,5-triaza-7-phosphaadamantane) ligand that is able to target Cu(ii) as well, reduce it and keep it in a safe complexed species. Removal of Cu(ii) from the amyloid-β peptide prevents the stabilization of oligomers and protofibrils and the complexation of Cu(i) also stops the formation of reactive oxygen species. Besides, zinc, which is found in the synaptic cleft at a higher concentration than copper, can hamper the ability of metal-targeting drug candidates, an issue that is still poorly considered and studied. Here we show that PTA fully retains the above described properties even in the presence of zinc, thus fulfilling an additional pre-requisite for its use as a model of Cu(i)-targeting drug candidates in the Alzheimer's disease context.