Prediction of Soluble-Solid Content in Citrus Fruit Using Visible-Near-Infrared Hyperspectral Imaging Based on Effective-Wavelength Selection Algorithm.

Citrus fruits were sorted based on external qualities, such as size, weight, and color, and internal qualities, such as soluble solid content (SSC), acidity, and firmness. Visible and near-infrared (VNIR) hyperspectral imaging techniques were used as rapid and nondestructive techniques for determining the internal quality of fruits. The applicability of the VNIR hyperspectral imaging technique for predicting the SSC in citrus fruits was evaluated in this study. A VNIR hyperspectral imaging system with a wavelength range of 400-1000 nm and 100 W light source was used to acquire hyperspectral images from citrus fruits in two orientations (i.e., stem and calyx ends). The SSC prediction model was developed using partial least-squares regression (PLSR). Spectrum preprocessing, effective wavelength selection through competitive adaptive reweighted sampling (CARS), and outlier detection were used to improve the model performance. The performance of each model was evaluated using the coefficient of determination (R2) and root mean square error (RMSE). In the present study, the PLSR model was developed using only a citrus cultivar. The SSC prediction CARS-PLSR model with outliers removed exhibited R2 and RMSE values of approximatively 0.75 and 0.56 °Brix, respectively. The results of this study are expected to be useful in similar fields such as agricultural and food post-harvest management, as well as in the development of an online system for determining the SSC of citrus fruits.

Comprehensive stability analysis of 13 ß-lactams and ß-lactamase inhibitors in in vitro media, and novel supplement dosing strategy to mitigate thermal drug degradation.

Non-clinical antibiotic development relies on in vitro susceptibility and infection model studies. Validating the achievement of the targeted drug concentrations is essential to avoid under-estimation of drug effects and over-estimation of resistance emergence. While certain ß-lactams (e.g., imipenem) and ß-lactamase inhibitors (BLIs; clavulanic acid) are believed to be relatively unstable, limited tangible data on their stability in commonly used in vitro media are known. We aimed to determine the thermal stability of 10 ß-lactams and 3 BLIs via LC-MS/MS in cation-adjusted Mueller Hinton broth at 25 and 36°C as well as agar at 4 and 37°C, and in water at -20, 4, and 25°C. Supplement dosing algorithms were developed to achieve broth concentrations close to their target over 24 h. During incubation in broth (pH 7.25)/agar, degradation half-lives were 16.9/21.8 h for imipenem, 20.7/31.6 h for biapenem, 29.0 h for clavulanic acid (studied in broth only), 23.1/71.6 h for cefsulodin, 40.6/57.9 h for doripenem, 46.5/64.6 h for meropenem, 50.8/97.7 h for cefepime, 61.5/99.5 h for piperacillin, and >120 h for all other compounds. Broth stability decreased at higher pH. All drugs were ≥90% stable for 72 h in agar at 4°C. Degradation half-lives in water at 25°C were >200 h for all drugs except imipenem (14.7 h, at 1,000 mg/L) and doripenem (59.5 h). One imipenem supplement dose allowed concentrations to stay within ±31% of their target concentration. This study provides comprehensive stability data on ß-lactams and BLIs in relevant in vitro media using LC-MS/MS. Future studies are warranted applying these data to antimicrobial susceptibility testing and assessing the impact of ß-lactamase-related degradation.

Establishment of an LC-MS/MS method for quantification of lifitegrast in rabbit plasma and ocular tissues and its application to pharmacokinetic study.

Lifitegrast, a lymphocyte function-associated antigen 1 antagonist, was approved by the FDA for the treatment of dry eye disease. Cornea and conjunctiva have been reported to be the sites of action of lifitegrast. To investigate the pharmacokinetics of lifitegrast, a sensitive analytical method for the determination of lifitegrast in various biological matrices such as plasma and ocular tissues is required. However, only limited information about the analytical method for lifitegrast in biological samples is available. In the present study, we aimed to develop a new liquid chromatography-tandem mass spectrometry method for the determination of lifitegrast in rabbit plasma, cornea, conjunctiva, and sclera. Lifitegrast-d6 was used as an internal standard (IS). To prepare the biological samples, protein precipitation using acetonitrile was utilized. Analytes were separated from endogenous interferences on an Atlantis dC18 (5 µm, 2.1 × 150 mm), and a mixture of 0.1 % formic acid and acetonitrile was used as the mobile phase. The mass transition of precursor to product ion was monitored at 615.2 â†’ 145.0 for lifitegrast and 621.2 â†’ 145.1 for IS. The calibration curves were linear over the concentration range from 2 to 500 ng/mL for plasma and 5 to 500 ng/mL in ocular tissue homogenates. Intra- and inter-day accuracy ranged from 95.76 to 106.80 % in the plasma and 94.42 to 112.80 % in the ocular tissues. Precision was within 8.56 % in the plasma and 9.72 % in the ocular tissues. The short-term, long-term, auto-sampler, and freeze-thaw stabilities of lifitegrast were validated. The developed method was applied to a pharmacokinetic study of lifitegrast in rabbits. Following ophthalmic administration, only 3.26 % of administered lifitegrast was absorbed into the systemic circulation. Peak tissue concentrations were observed at 0.5 h after dosing, and topically administered lifitegrast was mainly distributed in the cornea and conjunctiva. The finding of this study is expected to be used in further pharmacokinetic studies and formulation development.

Novel modeling approach integrating population pharmacokinetics and interspecies scaling to predict human pharmacokinetics of the new anti-tuberculosis agent telacebec (Q203).

Telacebec is a new anti-tuberculosis agent with promising therapeutic activity and a favorable safety profile. This study aimed to characterize the pharmacokinetics of telacebec via interspecies scaling and population pharmacokinetic modeling for the prediction of human pharmacokinetics. Preclinical pharmacokinetic data were obtained from mice, rats, and dogs following intravenous and oral doses of telacebec. A population pharmacokinetic model was developed to describe the pharmacokinetic data from all three species. The disposition parameters were well correlated with the body weight for all species using an allometric equation. Thus, the allometric scaling was incorporated into the population pharmacokinetic model, which could simultaneously describe the plasma concentration vs. time data from all preclinical studies as well as the Phase 1A clinical study. The developed model was used to predict the pharmacokinetics of telacebec after IV injection, including the clearance (CL) of 168.58 [118.86 - 238.73] mL/min and volume of distribution (Vss) of 968.84 [396.87 - 2831.31] L for 80-kg human. The absolute bioavailability of telacebec in humans in the fed state was estimated as 70.34 ± 9.91%. Finally, the population pharmacokinetic model with allometric scaling was utilized to simulate the plasma concentration vs. time profiles of telacebec after multiple oral doses in humans. The model-predicted profiles well agreed with the observed data in Phase 1B clinical trial. The present pharmacokinetic model may help better understand the activity of telacebec, leading to the design of optimal dosing regimens and new formulation development.

Development of an LC-MS/MS Assay and Toxicokinetic Characterization of Hexamethylenetetramine in Rats.

Hexamethylenetetramine, an aldehyde-releasing agent, is used as a preservative in various food, cosmetics, and medical treatments, such as a treatment for urinary tract infections. It has been reported to be allergenic on contact with the skin, with the additional possibility of causing toxicity once absorbed systemically. Despite its potential toxicity, there are no reports on the in vivo bioavailability of hexamethylenetetramine following oral or dermal administration. In this study, we developed a new simple and sensitive LC-MS/MS method for the determination of hexamethylenetetramine in plasma and applied this method to characterize the toxicokinetics. The developed assay had a sufficient specificity and sensitivity for toxicokinetic characterization, and its accuracy and precision were verified. Following iv injection, the plasma concentration of hexamethylenetetramine showed mono exponential decay, with an elimination half-life of about 1.3 h. Following oral administration, the Tmax reached an average of 0.47 h and bioavailability was estimated as 89.93%. After percutaneous administration, it reached Cmax on average at 2.9-3.6 h. Although the absorption rate was relatively slow, its average bioavailability was calculated as 77.19-78.91%. Overall, most of the orally and percutaneously administered hexamethylenetetramine was absorbed into systemic circulation. The derived results in this study are expected to be utilized as the scientific evidence for further toxicokinetic study and risk assessment.

Novel LC-MS/MS analysis of the GLP-1 analog semaglutide with its application to pharmacokinetics and brain distribution studies in rats.

Semaglutide, one of the most potent glucagon-like peptide (GLP)-1 analogs, has widely been used to treat type II diabetes mellitus and obesity. Recent studies have shown that semaglutide also works on the brain, suggesting its potential utility for various diseases, including Parkinson's disease and Alzheimer's disease. This study aimed to develop a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of semaglutide in both plasma and brain to characterize the pharmacokinetics and brain distribution in rats. Semaglutide was extracted by simple protein precipitation with methanol from plasma and by solid phase extraction from brain tissue. Liraglutide was used as an internal standard. Gradient elution profiles with mobile phases comprising 0.1 % formic acid in water and acetonitrile were used for chromatographic separation. The lower limit of quantification (LLOQ) of the LC-MS/MS assay was 0.5 ng/mL for both rat plasma and brain. Intra- and inter-day accuracy ranged 89.20-109.50 % in the plasma and 92.00-105.00 % in the brain. Precision was within 8.92 % in the plasma and 7.94 % in the brain. Sprague-Dawley rats were given semaglutide by intravenous (IV, 0.02 mg/kg) and subcutaneous (SC, 0.1 and 0.2 mg/kg) injection. Plasma concentrations of semaglutide showed a multi-exponential decline with an average half-life of 7.22-9.26 hr in rats. The subcutaneous bioavailability of semaglutide was 76.65-82.85 %. The brain tissue to plasma partition coefficient (Kp) value of semaglutide was estimated as <0.01. Among the different regions of the brain, semaglutide concentrations were significantly higher in the hypothalamus. The analytical method and pharmacokinetic information may be helpful toward a better understanding of the effect of semaglutide in the brain and further development of GLP-1 analogs for various brain diseases.

Safety, Tolerability, Pharmacokinetics, and Metabolism of Telacebec (Q203) for the Treatment of Tuberculosis: a Randomized, Placebo-Controlled, Multiple Ascending Dose Phase 1B Trial.

A phase 1b, randomized, placebo-controlled, double-blind, multiple ascending dose study (NCT02858973) was conducted to assess the safety, tolerability, and pharmacokinetics of the new antituberculosis agent telacebec (Q203). A total of 47 healthy adult subjects entered the study; 36 received telacebec, and 11 received placebo. Telacebec at doses of 20, 50, 100, 160, 250, and 320 mg was orally administered once daily with a standard meal for 14 days. Multiple oral doses of telacebec up to 320 mg daily for 14 days appeared to be safe and well tolerated by healthy adult subjects in this study. There were no deaths, serious adverse events, or subject discontinuations due to adverse events. Following oral doses of telacebec, the overall extent (AUCτ) and peak (Cmax) exposures of telacebec increased from 538.94 to 10,098.47 ng·h/mL and from 76.43 to 1502.33 ng/mL, respectively, with increasing telacebec doses from 20 mg to 320 mg. A steady state was achieved for plasma telacebec by day 12, and there was 1.9- to 3.1-fold accumulation in the extent of telacebec exposure after daily doses for 14 days. Analysis of plasma samples from the participants indicated that telacebec was the primary circulating entity with no significant metabolites. Three potential metabolites of telacebec have been identified, which may be relatively minimal compared to the parent drug. Consistent with findings from preclinical and previous single-dose clinical studies, these results also support the potential of telacebec for further development as a safe and effective agent for the treatment of tuberculosis.

Toxicokinetics, Percutaneous Absorption and Tissue Distribution of Benzophenone-3, an UV Filtering Agent, in Rats.

The aim of this study was to evaluate in vitro skin permeation and deposition, in vivo toxicokinetics, percutaneous absorption and tissue distribution of benzophenone-3 (BP-3) in rats. Four transdermal formulations containing BP-3 were prepared and evaluated for in vitro skin permeation and deposition of BP-3 using Franz diffusion cells. A gel formulation was used in subsequent in vivo percutaneous absorption due to its high in vitro skin permeation and deposition. Compared to intravenous (i.v.) injection, the prolonged terminal t1/2 (3.1 ± 1.6 h for i.v. injection and 18.3 ± 5.8 h for topical application) was observed indicating occurrence of flip-flop kinetics after topical application. The bioavailability of BP-3 after topical application was 6.9 ± 1.8%. The tissue-to-plasma partition coefficient (kp) for testis, considered a toxic target for BP-3, was less than 1.. Overall, findings of this study may be useful for risk assessment of BP-3.

Combined phototherapy with metabolic reprogramming-targeted albumin nanoparticles for treating breast cancer.

Triple-negative breast cancer (TNBC) is characterized by rapid tumor growth and resistance to cancer therapy, and has a poor prognosis. Accumulating data have revealed that cancer metabolism relies on both the Warburg effect and oxidative phosphorylation (OXPHOS), which are strongly related to the high proliferation and chemoresistance of cancer cells. Phototherapy is considered as a non-invasive method to precisely control drug activity with reduced side effects. Herein, our group introduced an Abraxane-like nanoplatform, named LCIR NPs, which significantly eradicates cancer cells via synergism between metabolic reprogramming and phototherapy effects. Endowed with mitochondria-targeting residues, the nanoparticles efficiently inhibited mitochondrial complexes I and IV as well as hexokinase II, leading to the depletion of intracellular ATP. Consequently, the photodynamic and photothermal effect triggered by NIR irradiation was enhanced due to the alleviation of hypoxia and the thermoresistance mechanism that rely on mitochondrial metabolism. In vivo experiments showed that the tumor size of mice that received the combination treatment was only 50.7 mm3, which was 21 times smaller than that of the untreated group and was much lower than those of other single treatments after 21 days. Additionally, almost no systemic undesired toxicity was detected during the observation period. We believe that the concept of LCIR as presented here offers a potential platform to overcome the resistance to conventional therapies by the incorporation with the energy metabolism inhibition approach.

Determination of pharmacokinetics and tissue distribution of a novel lutetium-labeled PSMA-targeted ligand, 177Lu-DOTA-PSMA-GUL, in rats by using LC-MS/MS.

Prostate specific membrane antigen (PSMA) is known to be overexpressed in prostate cancer cells, providing as a diagnostic and therapeutic target for prostate cancer. A lutetium-labeled PSMA targeted ligand, 177Lu-DOTA-PSMA-GUL is a novel radiopharmaceutical, which has been developed for the treatment of prostate cancer. While the GUL domain of 177Lu-DOTA-PSMA-GUL binds to the antigen, the beta-emitting radioisotope, 177Lu-labeled DOTA, interacts with prostate cancer cells. However, the in vivo pharmacokinetics of intact 177Lu-DOTA-PSMA-GUL has never been characterized. This study aimed to evaluate the pharmacokinetics and tissue distribution of the radiopharmaceutical in rats by using its stable isotope-labeled analog, 175Lu-DOTA-PSMA-GUL. A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of 175Lu-DOTA-PSMA-GUL was developed and validated. Following intravenous injection, the plasma concentration-time profiles of 175Lu-DOTA-PSMA-GUL showed a multi-exponential decline with the average elimination half-life of 0.30 to 0.33 h. Systemic exposure increased with the dose and renal excretion is the major elimination route. Tissue distribution of 175Lu-DOTA-PSMA-GUL was most substantial in kidneys, followed by the prostate. The developed LC-MS/MS assay and the in vivo pharmacokinetic data of 175Lu-DOTA-PSMA-GUL would provide helpful information for further clinical studies to be developed as a novel therapeutic agent for prostate cancer.

Establishment of Level a In Vitro-In Vivo Correlation (IVIVC) via Extended DoE-IVIVC Model: A Donepezil Case Study.

This study aimed to establish an extended design of experiment (DoE)-in vitro in vivo correlation (IVIVC) model that defines the relationship between formulation composition, in vitro dissolution, and in vivo pharmacokinetics. Fourteen sustained-release (SR) tablets of a model drug, donepezil, were designed by applying a mixture design of DoE and prepared by the wet granulation method. The in vitro dissolution patterns of donepezil SR tablets were described by Michaelis-Menten kinetics. The mathematical relationship describing the effects of SR tablet compositions on the in vitro dissolution parameter, i.e., the in vitro maximum rate of release (Vmax), was derived. The predictability of the derived DoE model was validated by an additional five SR tablets with a mean prediction error (PE%) of less than 3.50% for in vitro Vmax. The pharmacokinetics of three types of donepezil SR and the immediate-release (IR) tablets was assessed in Beagle dogs following oral administration (n = 3, each). Based on the plasma concentration-time profile, a population pharmacokinetic model was developed, and the in vivo dissolution of SR tablets, represented by in vivo Vmax, was estimated. By correlating the in vitro and in vivo Vmax, level A IVIVC was established. Finally, the extended DoE-IVIVC model was developed by integrating the DoE equation and IVIVC into the population pharmacokinetic model. The extended DoE-IVIVC model allowed one to predict the maximum plasma concentration (Cmax) and the area under the plasma concentration-time curve (AUC) of donepezil SR tablets with PE% less than 10.30% and 5.19%, respectively, by their formulation composition as an input. The present extended DoE-IVIVC model may provide a valuable tool to predict the effect of formulation changes on in vivo pharmacokinetic behavior, leading to the more efficient development of SR formulations. The application of the present modeling approaches to develop other forms of drug formulation may be of interest for future studies.

Pharmacokinetics of Nafamostat, a Potent Serine Protease Inhibitor, by a Novel LC-MS/MS Analysis.

Nafamostat, a synthetic serine protease inhibitor, has been used for the treatment of inflammatory diseases such as pancreatitis. Recently, an increasing number of studies have shown the promising antiviral effects of nafamostat for the treatment of coronavirus disease-19 (COVID-19). This study aimed to develop a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis and to characterize the pharmacokinetics of nafamostat in rats. Nafamostat in the rat plasma was extracted by solid phase extraction, and 13C6-nafamostat was used as an internal standard. The quantification limit of nafamostat in the rat plasma was 0.5 ng/mL. The LC-MS/MS method was fully validated and applied to characterize the pharmacokinetics of nafamostat in rats. Following intravenous injection (2 mg/kg), nafamostat in the plasma showed a multiexponential decline with an average elimination half-life (t1/2) of 1.39 h. Following oral administration of nafamostat solutions (20 mg/kg) in 10% dimethyl sulfoxide (DMSO) and in 10% DMSO with 10% Tween 80, nafamostat was rapidly absorbed, and the average oral bioavailability was 0.95% and 1.59%, respectively. The LC-MS/MS method and the pharmacokinetic information of nafamostat could be helpful for the further preclinical and clinical studies of nafamostat.

Novel extended IVIVC combined with DoE to predict pharmacokinetics from formulation compositions.

The objective of this study was to develop a novel extended in vitro in vivo correlation (IVIVC) model combined with design of experiment (DoE) that integrates the DoE into IVIVC, which can predict the pharmacokinetics of sustained-release (SR) tablets from their formulation compositions, and vice versa. To develop the extended IVIVC model, ketoprofen was used as a model drug. Nineteen types of ketoprofen SR tablets with different formulation compositions were prepared based on the mixture design and used to derive mathematical relationships between the formulation composition and the in vitro dissolution profiles for DoE. The predictability of the DoE equation was externally validated by using additional seven types of SR formulations with prediction errors (%PE) of less than 11.45%. For the development of IVIVC model, three SR formulations that have fast, medium, and slow drug-releasing rates were selected, and the in vivo pharmacokinetics were assessed in Beagle dogs. The pharmacokinetic properties of ketoprofen SR tablets were described by a population pharmacokinetics (POP-PK) model which incorporated the pH-dependent dissolution of ketoprofen by a time-dependent Hill-type equation. The final POP-PK model could describe the overall in vivo pharmacokinetic profiles and allowed estimation of the in vivo dissolution parameters. The POP-PK model estimated in vivo dissolution parameter, Kdiss, in vivo were then correlated with the in vitro dissolution parameter, Kdiss, in vitro by linear regression (R2 = 0.9989), establishing IVIVC. Finally, the equation derived from DoE was introduced to the IVIVC model to develop the extended IVIVC, which connects the formulation composition, in vitro dissolution, and in vivo pharmacokinetic profiles. The average %PE of the final extended IVIVC model was 4.24% for Cmax and 4.46% and AUC. Finally, the final extended IVIVC was applied to predict the in vivo PK profiles of SR tablets from their formulation compositions as well as to design the optimal formulation to achieve certain target PK profiles. The %PE of the final extended IVIVC model was less than 14.67% for Cmax and 12.41% for AUC, satisfying the FDA criteria of conventional IVIVC. The present extended IVIVC model may provide a useful tool towards rationalized design and development of new SR formulations.

Development of Multiple UAV Collaborative Driving Systems for Improving Field Phenotyping.

Unmanned aerial vehicle-based remote sensing technology has recently been widely applied to crop monitoring due to the rapid development of unmanned aerial vehicles, and these technologies have considerable potential in smart agriculture applications. Field phenotyping using remote sensing is mostly performed using unmanned aerial vehicles equipped with RGB cameras or multispectral cameras. For accurate field phenotyping for precision agriculture, images taken from multiple perspectives need to be simultaneously collected, and phenotypic measurement errors may occur due to the movement of the drone and plants during flight. In this study, to minimize measurement error and improve the digital surface model, we proposed a collaborative driving system that allows multiple UAVs to simultaneously acquire images from different viewpoints. An integrated navigation system based on MAVSDK is configured for the attitude control and position control of unmanned aerial vehicles. Based on the leader-follower-based swarm driving algorithm and a long-range wireless network system, the follower drone cooperates with the leader drone to maintain a constant speed, direction, and image overlap ratio, and to maintain a rank to improve their phenotyping. A collision avoidance algorithm was developed because different UAVs can collide due to external disturbance (wind) when driving in groups while maintaining a rank. To verify and optimize the flight algorithm developed in this study in a virtual environment, a GAZEBO-based simulation environment was established. Based on the algorithm that has been verified and optimized in the previous simulation environment, some unmanned aerial vehicles were flown in the same flight path in a real field, and the simulation and the real field were compared. As a result of the comparative experiment, the simulated flight accuracy (RMSE) was 0.36 m and the actual field flight accuracy was 0.46 m, showing flight accuracy like that of a commercial program.

Comparison of the exposure assessment of di(2-ethylhexyl) phthalate between the PBPK model-based reverse dosimetry and scenario-based analysis: A Korean general population study.

Di (2-ethylhexyl) phthalate (DEHP), classified as a reproductive toxicant, is a ubiquitous pollutant in foodstuffs, dust, and commercial products. In this study, to provide a useful cross-check on the accuracy of the exposure assessment, the estimated daily intake of DEHP was compared using reverse dosimetry with a physiologically-based pharmacokinetic (PBPK) model and a scenario-based probabilistic estimation model for six subpopulations in Korea. For reverse dosimetry analysis, the concentrations of urinary DEHP metabolites, namely mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono (2-ethyl-5-oxohexyl)phthalate (MEOHP), from three human biomonitoring program datasets were used. For the scenario-based model, we evaluated the various exposure sources of DEHP, including diet, air, indoor dust, soil, and personal care products (PCPs), and also determined its levels based on the literature review and measurements of indoor dust. The DEHP exposure doses using both exposure assessment approaches were similar in all cases, except for the 95th percentile exposure doses in toddlers (1-2 years) and young children (3-6 years). The PBPK-reverse dosimetry estimated daily intakes at the 95th percentile ranged between 22.53 and 29.90 µg/kg/day for toddlers and young children. These exceeded the reference dose (RfD) of 20 µg/kg bw/day of the US Environmental Protection Agency (EPA) based on the increased relative liver weight. Although, food was considered the primary source of DEHP, contributing to a total exposure of 50.8-75.1%, the effect of exposure to indoor dust should not be overlooked. The occurrence of high levels of DEHP in indoor dust collected from Korean homes suggests the use of a wide variety of consumer products containing DEHP. Furthermore, more attention should be paid to the high exposure levels of DEHP, especially in young children. Therefore, it is necessary to perform continuous monitoring of the indoor dust, consumer products, and the body burden of children.

Safety, Tolerability, and Pharmacokinetics of Telacebec (Q203), a New Antituberculosis Agent, in Healthy Subjects.

Telacebec (Q203) is a potent drug candidate under clinical development for the treatment of drug-naïve and drug-resistant tuberculosis. The first-in-human randomized, placebo-controlled, double-blind, dose-escalation Phase 1A trial (Q203-TB-PI-US001) was conducted to evaluate the safety, tolerability, and pharmacokinetics of telacebec. A total of 56 normal, healthy, male and female subjects (42 active and 14 placebo) were enrolled in the study. The doses of telacebec were 10 mg (Cohort 1), 30 mg (Cohort 2), 50 mg (Cohort 3), 100 mg (Cohort 4), 200 mg (Cohort 5), 400 mg (Cohort 6), and 800 mg (Cohort 7) in a fasted state. Subjects participating in Cohort 4 were also enrolled in Cohort 8 to investigate the food effect on the pharmacokinetics of telacebec after a high-fat meal. In all subjects dosed with telacebec (10 to 800 mg), telacebec was well tolerated and did not lead to any significant or serious adverse events. Following a single oral administration of telacebec (10 to 800 mg), telacebec plasma concentration reached the maximal plasma concentration (Cmax) in average 2.0 to 3.5 h and showed multi-exponential decline thereafter. The area under the plasma concentration versus time curve (AUC) was approximately dose-proportional. A significant increase in plasma concentrations was observed in the fed condition compared with the fasted condition with the geometric mean ratio of 3.93 for Cmax. Moderate delay in Tmax (4.5 h) was also observed in the fed condition. These results, combined with the demonstrated activity against drug-sensitive and multidrug-resistant Mycobacterium tuberculosis, support further investigation of telacebec for the treatment of tuberculosis.

Newly Synthesized DNA Methyltransferase Inhibitors as Radiosensitizers for Human Lung Cancer and Glioblastoma Cells.

BACKGROUND/AIM: Improvement of the efficacy of radiotherapy for lung cancer and glioblastoma is urgently needed. MATERIALS AND METHODS: We synthesized several novel DNA methyltransferase inhibitors and evaluated their potentials as possible radiosensitizers. Eleven non-nucleoside compounds were synthesized and evaluated along with one known compound using human lung cancer (A549) and glioblastoma (U373MG) cells. Cytotoxicity and radiosensitizing effects were evaluated using clonogenic assay. Sensitizer enhancement ratios at a survival fraction of 0.5 were calculated, and statistical analysis was performed using the ratio paired t-test. The inhibitory effects of three selected compounds on the activity of DNA methyltransferase 1 (DNMT1) and the pharmacokinetic profiles were analyzed. RESULTS: All twelve compounds demonstrated various levels of cytotoxicity. Of the twelve compounds, eleven and eight compounds radiosensitized A549 and U373MG cells, respectively, with at least marginal significance (p<0.10). The sensitizer enhancement ratios in A549 and U373MG ranged 1.166-2.537 and 1.083-1.743 among compounds with radiosensitizing effects, respectively. The three selected compounds inhibited DNMT1 activity by 26.5-78.5%. Elimination half-lives ranged from 0.3 to 1.3 h. CONCLUSION: Novel DNA methyltransferase inhibitors with significant radiosensitizing capacity and improved biostability were synthesized. These materials will serve as a basis for the development of novel radiosensitizers.

Pharmacokinetics of panduratin A following oral administration of a Boesenbergia pandurata extract to rats.

Boesenbergia pandurata and its major active ingredient, panduratin A (PAN), exhibit antibacterial, anti-oxidant, anti-inflammatory, and anti-obesity effects. We explored the time course of the plasma and tissue (in the major organs, gums and skin) concentrations of PAN after oral administration of a B. pandurata extract to rats. Model-dependent analysis was used to quantify the skin distribution of PAN after systemic exposure. The PAN level peaked at 1.12 ± 0.22 µg/mL after 3 h, and then biexponentially decayed with a terminal half-life of 9 h. The mean clearance (Cl/F) was 2.33 ± 0.68 L/h/kg. The PAN levels in organs were in the following order (highest first): skin, lung, heart, gum, liver, spleen, kidney, and brain. For the first time, the time course of PAN levels in plasma and organs was investigated after oral administration of a BPE. This study helps to explain the pharmacological activities of PAN in the skin and gums. The pharmacokinetic model provided data in the plasma and skin concentrations of PAN, which are of fundamental importance to evaluate its efficacy.

Pharmacokinetics of Shikimic Acid Following Intragastric and Intravenous Administrations in Rats.

Shikimic acid, a critical starting material for the semi-total synthesis of oseltamivir to treat and prevent influenza, exerts many pharmacological effects. However, the optimal bioanalytical method has not been adequately defined. We used liquid chromatography-tandem mass spectrometry to quantitate shikimic acid in rat plasma and studied its pharmacokinetics after intragastric and intravenous administration. Plasma was spiked with an internal standard, and the proteins were precipitated with acetonitrile, followed by solvent evaporation and reconstitution of the mobile phase. Shikimic acid was separated on a hydrophilic reverse-phase column and showed a mass transition ([M-H]-) at m/z 173.4→136.6. Shikimic acid exhibited bi-exponential decay after intravenous dosing, with a rapid distribution (5.57 h-1) up to 1 h followed by slow elimination (0.78 h-1). The steady state distribution and clearance volumes were 5.17 and 1.79 L/h/kg, respectively. After intragastric administration, the shikimic acid level peaked at about 3 h, and the material then disappeared mono-exponentially with a half-life of 1.3 h. A double peak phenomenon was observed. The absolute oral bioavailability was about 10% in rats. We explored the relationship between the pharmacokinetics and pharmacodynamics of shikimic acid.

3D-Printed Gastroretentive Sustained Release Drug Delivery System by Applying Design of Experiment Approach.

This study aimed to develop a novel oral drug delivery system for gastroretentive sustained drug release by using a capsular device. A capsular device that can control drug release rates from the inner immediate release (IR) tablet while floating in the gastric fluid was fabricated and printed by a fused deposition modeling 3D printer. A commercial IR tablet of baclofen was inserted into the capsular device. The structure of the capsular device was optimized by applying a design of experiment approach to achieve sustained release of a drug while maintaining sufficient buoyancy. The 2-level factorial design was used to identify the optimal sustained release with three control factors: size, number, and height of drug-releasing holes of the capsular device. The drug delivery system was buoyant for more than 24 h and the average time to reach 80% dissolution (T80) was 1.7-6.7 h by varying the control factors. The effects of the different control factors on the response factor, T80, were predicted by using the equation of best fit. Finally, drug delivery systems with predetermined release rates were prepared with a mean prediction error ≤ 15.3%. This approach holds great promise to develop various controlled release drug delivery systems.