Search

A soya milk production and pasteurization plant was designed, fabricated and tested. The machine processed soaked soya milk to milk and also pasteurized it. Its major component parts include blending chamber, blending blade, furnace, boiler, temperature gauge and pasteurization chamber. The blending of soya beans, mixing the slurry and extracting the milk from the paste takes place in the milling chamber. The burning of biomass (briquette) takes place in the furnace and heating of water at the boiler. The pasteurization takes place in the pasteurizer. The machine capacity is 750 liters in 8 hours operational time per day. The results of testing of the machine revealed that blending efficiency and yield of milk were 88.16%, 98.52% respectively. The selected pasteurization temperature and time used were 84°C and 30 seconds. The machine was able to increase shelf life of raw soya milk from 24 (1 day) to 48 hours (2 day) when stored under room temperature and to 144 hours (6 day) when stored at temperature of 4oC (refrigerated). [ABSTRACT FROM AUTHOR]

The research work was conducted to develop an automated grain drinks processing machine capable of integrating several operations (blending of soaked grains, mixing the slurry, extracting the aqueous liquid and discharging of the paste out of the machine) together and finished in one go. Fundamental design analysis and calculations were carried out in order to determine and select materials of appropriate strength and sizes for the machine component parts. The major machine parts include hopper, delivery tube, blending chamber, blade, conical centrifugal basket, electric motors and control system. The results of testing of the machine using soya beans revealed that blending efficiency of 85.52% was obtained from combination of 3 blades assembly, basket with half angle of 30 and speed of 1400 rpm. The optimisation of the machine parameters using response surface methodology produced optimum paste expelling efficiency of 94.89% with desirability of 94.3% from combination of 3-blades assembly, basket of half angle of 50 and speed of 1400 rpm. The speed of rotation and basket angle has positive significant effects on the paste expelling efficiency while blade number has insignificant effect. Paste expelling efficiency increase with both increased in speed of rotation and basket angle. The machine capacity and cost of production are 100 L per hour and $ 1670 respectively. [ABSTRACT FROM AUTHOR]

Cystic fibrosis is one of the most common genetic diseases among caucasian population. This disease is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene encoding for the CFTR protein. Lumacaftor, elexacaftor, tezacaftor, and ivacaftor were currently used as the treatment to Cystic fibrosis. In this study, we describe a new method for the simultaneous quantification of four molecules: lumacaftor, elexacaftor, tezacaftor, and ivacaftor, alongside two metabolites of ivacaftor, specifically hexyl-methyl ivacaftor and ivacaftor carboxylate by liquid chromatography-tandem mass spectrometry. This method holds significant utility for therapeutic drug monitoring and the optimization of treatments related to CFTR modulators. Molecules were extracted from 100 µL of plasma by a simple method of protein precipitation using acetonitrile. Following extraction, chromatographic separation was carried out by reverse chromatography on a C18 analytical column, using a gradient elution of water (0.05 % formic acid, V/V) and acetonitrile (0.05 % formic acid, V/V). The run time was 7 minutes at a flow rate of 0.5 mL/min. After separation, molecules were detected by electrospray ionization on a Xevo TQD triple-quadrupole-mass-spectrometer (Waters®, Milford, USA). The calibration range were: 0.053-20.000 mg/L for elexacaftor, tezacaftor and lumacaftor, 0.075-14.000 mg/L for ivacaftor, and 0.024-6.500 mg/L for hexyl-methyl ivacaftor and ivacaftor carboxylate. The proposed method underwent throughout validation demonstrating satisfactory precision (inter- and intra-day coefficients of variation less than 14.3 %) and a good accuracy (inter- and intra-day bias ranging between -13.7 % and 14.7 %) for all the analytes. The presented method for the simultaneous quantification of CFTR modulators and their metabolites in human plasma has undergone rigorous validation process yielding good results including strong precision and accuracy for all analytes. This method has been effectively used in routine analytical analysis and clinical investigations within our laboratory., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aims: Vigabatrin is an antiepileptic drug used to treat some forms of severe epilepsy in children. The main adverse effect is ocular toxicity, which is related to the cumulative dose. The aim of the study is to identify an acceptable exposure range, both through the development of a population pharmacokinetic model of vigabatrin in children enabling us to calculate patient exposure and through the study of therapeutic response., Methods: We performed a retrospective study including children with epilepsy followed at Necker-Enfants Malades hospital who had a vigabatrin assay between January 2019 and January 2022. The population pharmacokinetic study was performed on Monolix2021 using a nonlinear mixed-effects modelling approach. Children treated for epileptic spasms were classified into responder and nonresponder groups according to whether the spasms resolved, in order to identify an effective plasma exposure range., Results: We included 79 patients and analysed 159 samples. The median age was 4.2 years (range 0.3-18). A 2-compartment model with allometry and creatinine clearance on clearance best fit our data. Exposure analysis was performed on 61 patients with epileptic spasms. Of the 22 patients who responded (36%), 95% had an AUC 0-24 between 264 and 549 mg.h.L -1 ., Conclusions: The population pharmacokinetic model allowed us to identify bodyweight and creatinine clearance as the 2 main factors explaining the observed interindividual variability of vigabatrin. An acceptable exposure range was defined in this study. A target concentration intervention approach using this pharmacokinetic model could be used to avoid overexposure in responder patients., (© 2024 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

We aimed to develop a piperacillin population pharmacokinetic (PK) model in critically ill children receiving continuous renal replacement therapy (CRRT) and to optimize dosing regimens. The piperacillin plasma concentration was quantified by high-performance liquid chromatography. Piperacillin PK was investigated using a nonlinear mixed-effect modeling approach. Monte Carlo simulations were performed to compute the optimal scheme of administration according to the target of 100% interdose interval time in which concentration is one to four times above the MIC (100% fT > 1 to 4× MIC). A total of 32 children with a median (interquartile range [IQR]) postnatal age of 2 years (0 to 11), body weight (BW) of 15 kg (6 to 38), and receiving CRRT were included. Concentration-time courses were best described by a one-compartment model with first-order elimination. BW and residual diuresis ( Q u ) explained some between-subject variabilities on volume of distribution ( V ), where [Formula: see text], and clearance (CL), where [Formula: see text], where CL pop and V pop are 6.78 L/h and 55.0 L, respectively, normalized to a 70-kg subject and median residual diuresis of 0.06 mL/kg/h. Simulations with intermittent and continuous administrations for 4 typical patients with different rates of residual diuresis (0, 0.1, 0.25, and 0.5 mL/kg/h) showed that continuous infusions were appropriate to attain the PK target for patients with residual diuresis higher than 0.1 mL/kg/h according to BW and MIC, while for anuric patients, less frequent intermittent doses were mandatory to avoid accumulation. Optimal exposure to piperacillin in critically ill children on CRRT should be achieved by using continuous infusions with escalating doses for high-MIC bacteria, except for anuric patients who require less frequent intermittent doses.

Background and Objective: We aimed to develop a meropenem population pharmacokinetic model in critically ill children receiving continuous renal replacement therapy and simulate dosing regimens to optimize patient exposure., Methods: Meropenem plasma concentration was quantified by high-performance liquid chromatography. Meropenem pharmacokinetics was investigated using a non-linear mixed-effect modeling approach. Monte Carlo simulations were performed to compute the optimal scheme of administration, according to the target of a 100% inter-dose interval time in which concentration is one to four times above the minimum inhibitory concentration (100% fT>1-4×MIC)., Results: A total of 27 patients with a median age of 4 [interquartile range 0-11] years, a median body weight of 16 [range 7-35] kg receiving continuous renal replacement therapy were included. Concentration-time courses were best described by a one-compartment model with first-order elimination. Body weight (BW) produced significant effects on volume of distribution (V) and BW and continuous renal replacement therapy effluent flow rate (Q eff ) produced significant effects on clearance (CL): [Formula: see text] and [Formula: see text], where V pop and CL pop estimates were 32.5 L and 5.88 L/h, respectively, normalized to a 70-kg BW and median Q eff at 1200 mL/h. Using this final model and Monte Carlo simulations, for patients with Q eff over 1200 mL/h, meropenem continuous infusion was adequate in most cases to attain 100% fT> 1 - 4xMIC . For bacterial infections with a low minimum inhibitory concentration (≤2 mg/L), meropenem intermitent administration was appropriate for patients weighing more than 20 kg with Q eff <500 mL/h and for patients weighing more than 10 kg with Q eff <100 mL/h., Conclusions: Meropenem exposure in critically ill children receiving continuous renal replacement therapy needs dosing adjustments to the minimum inhibitory concentration that take into account body weight and the continuous renal replacement therapy effluent flow rate., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Septic critically ill children are at a high risk of inadequate antibiotic exposure, requiring them to undergo therapeutic drug monitoring (TDM). The aim of this study was to describe the use of TDM for antibiotics in critically ill children., Methods: The authors conducted a single-center observational study between June and December 2019, with all children treated with antibiotics in a pediatric intensive care unit located in a French university hospital. Standard clinical and laboratory data were recorded. Blood samples were collected for routine laboratory tests, and plasma antibiotic levels were assayed using validated analytical methods., Results: A total of 209 children received antibiotics. TDM was performed in 58 patients (27.8%) who had a greater mean organ dysfunction (according to the International Pediatric Sepsis Consensus Conference) (3 versus 1 in the non-TDM group; P < 0.05) and were treated with antibiotics for longer. A total of 208 samples were analyzed. The median [interquartile range] assay turnaround time was 3 (1-5) days, and 48 (46.2%) of the 104 initial antibiotic concentration values were below the pharmacokinetic/pharmacodynamic targets. A total of 34 (46%) of the 74 off-target TDM measurements available before the end of the antibiotic treatment prompted dose adjustment. This dose adjustment increased the proportion of on-target TDM measurements (70% versus 20% without adjustment). Subsequent measurements of the minimum inhibitory concentration showed that the use of the European Committee on Antimicrobial Susceptibility Testing's epidemiological cutoff values led to underestimation of pharmacokinetic/pharmacodynamic target attainment in 10 cases (20%)., Conclusions: TDM seems to be an effective means of optimizing antibiotic exposure in critically ill children. This requires timely plasma antibiotic assays and minimum inhibitory concentration measurements. It is important to define which patients should undergo TDM and how this monitoring should be managed., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: This study aimed to characterize pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing scheme., Methods: Children treated with ciprofloxacin were included. Pharmacokinetics were described using non-linear mixed-effect modelling and validated with an external dataset. Monte Carlo simulations investigated dosing regimens to achieve a target AUC 0-24 h /MIC ratio ≥ 125., Results: A total of 189 children (492 concentrations) were included. A two-compartment model with first-order absorption and elimination best described the data. An allometric model was used to describe bodyweight (BW) influence, and effects of estimated glomerular filtration rate (eGFR) and age were significant on ciprofloxacin clearance., Conclusion: The recommended IV dose of 10 mg/kg q8h, not exceeding 400 mg q8h, would achieve AUC 0-24 h to successfully treat bacteria with MICs ≤ 0.25 (e.g. Salmonella, Escherichia coli, Proteus, Haemophilus, Enterobacter, and Klebsiella). A dose increase to 600 mg q8h in children > 40 kg and to 15 mg/kg q8h (max 400 mg q8h, max 600 mg q8h if augmented renal clearance, i.e., eGFR > 200 mL/min/1.73 m 2 ) in children < 40 kg would be needed for the strains with highest MIC (16% of Pseudomonas aeruginosa and 47% of Staphylococcus aureus). The oral recommended dose of 20 mg/kg q12h (not exceeding 750 mg) would cover bacteria with MICs ≤ 0.125 but may be insufficient for bacteria with higher MIC and a dose increase according bodyweight and eGFR would be needed. These doses should be prospectively confirmed, and a therapeutic drug monitoring could be used to refine them individually., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Levetiracetam is a broad-spectrum antiepileptic drug that exhibits high interindividual variability in serum concentrations in children. A population pharmacokinetic approach can be used to explain this variability and optimize dosing schemes. The objectives are to identify the best predictive population pharmacokinetic model for children and to evaluate recommended doses using simulations and Bayesian forecasting. A validation cohort included children treated with levetiracetam who had a serum drug concentration assayed during therapeutic drug monitoring. We assessed the predictive performance of all the population pharmacokinetic models published in the literature using mean prediction errors, root mean squared errors, and visual predictive checks. A population model was finally constructed on the data, and dose simulations were performed to evaluate doses. We included 267 levetiracetam concentrations ranging from 2 to 69 mg/L from 194 children in the validation cohort. Six published models were externally evaluated. Most of the models underestimated the variability of our population. A 1-compartment model with first-order absorption and elimination with allometric scaling was finally fitted on our data. In our cohort, 57% of patients had a trough concentration <12 mg/L and 12% <5 mg/L. To reach a trough concentration >5 mg/L, doses ≥30 mg/kg/d for patients ≤50 kg and ≥2000 mg/d for patients >50 kg are required. In our population, a high percentage of children had low trough concentrations. Our population pharmacokinetic model could be used for therapeutic drug monitoring of levetiracetam in children., (© 2021, The American College of Clinical Pharmacology.)

Lamotrigine is a broad-spectrum antiepileptic drug with high interindividual variability in serum concentrations in children. The aims of this study were to evaluate the predictive performance of pediatric population pharmacokinetic (PPK) models published on lamotrigine, to build a new model with our monitoring data and to evaluate the current recommended doses. A validation cohort included patients treated with lamotrigine who had a serum level assayed during therapeutic drug monitoring (TDM). PPK models published in the literature were first applied to the validation cohort. We assessed their predictive performance using mean prediction errors, root mean squared errors, and visual predictive checks. A new model was then built using the data. Dose simulations were performed to evaluate the doses recommended. We included 270 lamotrigine concentrations ranging from 0.5 to 17.9 mg/L from 175 patients. The median (range) age and weight were 11.8 years (0.8-18 years) and 32.7 kg (8-110 kg). We tested 6 PPK models; most had acceptable bias and precision but underestimated the variability of the cohort. We built a 1-compartment model with first-order absorption and elimination, allometric scaling, and effects of inhibitor and inducer comedications. In our cohort, 22.6% of trough concentrations were below 2.5 mg/L. In conclusion, we proposed a PPK model that can be used for TDM of lamotrigine in children. In our population, a high percentage of children had low trough concentrations of lamotrigine. As the intervals of recommended doses are large, we suggest aiming at the higher range of doses to reach the target concentration., (© 2020, The American College of Clinical Pharmacology.)

Dolutegravir, raltegravir and darunavir are three antiretroviral drugs widely used in combined antiretroviral therapies. These three drugs are highly bound to plasma proteins. Compared to the total concentration, the concentration of unbound drug which is considered as the only pharmacological active form should be more informative to improve therapeutic drug monitoring in patients to avoid virological failure or toxicity. The aim of the present study was to develop an ultrafiltration protocol and a LC-MS/MS method to simultaneously determine the concentrations of the unbound dolutegravir, raltegravir and darunavir in human plasma. Finally, 150 μL of plasma was ultrafiltrated using Centrifree® ultrafiltration devices with ultracel YM-T membrane (cutoff 30 KDa) during 5 min at 37 °C at 1500 g. Then, 20 μL of the ultrafiltrate were injected into the LC-MS/MS system. The chromatographic separation was carried out on a BEH C18 column using a mobile phase containing deionized water and acetonitrile, both with 0.05 % (v/v) of formic acid, with a gradient elution at a flow rate of 0.5 mL/min. The run time was only 4 min. The calibration curve ranged from 0.5-200 ng/mL for dolutegravir, 1 to 400 ng/mL for raltegravir and 10-4000 ng/mL for darunavir. This method was validated with a good precision (inter- and intra-day CV% lower than 14 %) and a good accuracy (inter- and intra-day bias between -5.6-8.8 %) for all the analytes. This method is simple, reliable and suitable for pharmacokinetic studies., Competing Interests: Declaration of Competing Interest There are no competing interests to declare., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Aims: Glomerular filtration rate (GFR) is difficult to assess in critically ill children using gold standard method and alternatives are needed. This study aimed to determine the most accurate GFR estimation formula for assessing piperacillin clearance in critically ill children, using a published piperacillin pharmacokinetics (PK) population model., Methods: All children hospitalized in the paediatric intensive care unit of a single institution who were receiving piperacillin were included. PK were described using the nonlinear mixed effect modelling software MONOLIX. In the initial PK model, GFR was estimated according to the Schwartz 1976 formula. We evaluated a set of 12 additional validated formulas, developed using plasma creatinine and/or cystatin C concentrations, in the building model to assess the lowest between-subject variability for piperacillin clearance., Results: We included 20 children with a median (range) postnatal age of 1.9 (0.1-19) years, body weight of 12.5 (3.5-69) kg. Estimated GFR according to the Schwartz 1976 formula was 160.5 (38-315) mL min -1 1.73 m -2 . Piperacillin clearance was best predicted by the Bouvet combined formula., Conclusion: The combined Bouvet formula was the most accurate GFR estimation formula for assessing piperacillin clearance in critically ill children., (© 2020 The British Pharmacological Society.)

Background: Although the efficacy of lopinavir/ritonavir has not been proven, it has been proposed as an off-label treatment for COVID-19. Previously, it has been reported that the plasma concentrations of lopinavir significantly increase in inflammatory settings. As COVID-19 may be associated with major inflammation, assessing the plasma concentrations and safety of lopinavir in COVID-19 patients is essential., Methods: Real-world COVID-19 data based on a retrospective study., Results: Among the 31 COVID-19 patients treated with lopinavir/ritonavir between March 18, 2020 and April 1, 2020, higher lopinavir plasma concentrations were observed, which increased by 4.6-fold (interquartile range: 3.6-6.2), compared with the average plasma concentrations in HIV. Lopinavir concentrations in all except one patient were above the upper limit of the concentration range of HIV treatment. Approximately one to 5 patients prematurely stopped treatment mainly because of an ADR related to hepatic or gastrointestinal disorders., Conclusions: Lopinavir plasma concentrations in patients with moderate-to-severe COVID-19 were higher than expected, and they were associated with the occurrence of hepatic or gastrointestinal adverse drug reactions. However, a high plasma concentration may be required for in vivo antiviral activity against SARS-CoV-2, as suggested by previous studies. Therefore, in the absence of adverse drug reaction, lopinavir dosage should not be reduced. Caution is essential because off-label use can be associated with a new drug safety profile., Competing Interests: The authors declare no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Therapeutic drug monitoring (TDM) is essential in the optimization of antiretroviral (ARV) treatments. In this work, we describe a new method for the simultaneous quantification of six molecules: the three novel ARV agents dolutegravir (DTG), elvitegravir (ELV) and rilpivirine (RPV), the first integrase inhibitor raltegravir (RAL) and its major metabolite the raltegravir-β-d-glucuronide (RAL-GLU), an protease inhibitor darunavir (DRV) and its booster ritonavir (RTV) in human plasma. The drugs were extracted from 100 μL of plasma by a simple method of protein precipitation using acetonitrile. The separation was carried out on a Kinetex phehyl-hexyl column using a phase mobile composed of 55 % of water (0.05 % formic acid,v/v) and 45 % of methanol (0.05 % formic acid,v/v). The flow rate was set at 0.5 mL/min. The calibration ranged from 60 to 15000 ng/mL for DRV, from 20 to 5000 ng/mL for DTG and ELV, from 10 to 2500 ng/mL for RAL, RAL-GLU, RTV and RPV. The proposed method was validated with a good precision (inter- and intra-day CV% inferior to 12.3 %) and a good accuracy (inter- and intra-day bias between -9.9 % and 10 %) for all the analytes. The proposed method is simple, reliable and suitable for therapeutic drug monitoring (TDM) and for pharmacokinetics studies., Competing Interests: Declaration of Competing Interest There are no competing interests to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: We aimed to develop a meropenem population pharmacokinetic (PK) model in critically ill children and simulate dosing regimens in order to optimize patient exposure., Methods: Meropenem plasma concentration was quantified by high-performance liquid chromatography. Meropenem PK was investigated using a non-linear mixed-effect modeling approach., Results: Forty patients with an age of 16.8 (1.4-187.2) months, weight of 9.1 (3.8-59) kg, and estimated glomerular filtration rate (eGFR) of 151 (19-440) mL/min/1.73 m 2 were included. Eleven patients received continuous replacement renal therapy (CRRT). Concentration-time courses were best described by a two-compartment model with first-order elimination. Body weight (BW), eGFR, and CRRT were covariates explaining the between-subject variabilities on central/peripheral volume of distribution (V1/V2), inter-compartment clearance (Q), and clearance (CL): V1 i  = V1 pop × (BW/70) 1 , Q i  = Q pop × (BW/70) 0.75 , V2 i  = V2 pop × (BW/70) 1 , CL i  = (CL pop × (BW/70) 0.75 ) × (eGFR/100) 0.378 ) for patients without CRRT and CL i  = (CL pop × (BW/70) 0.75 ) × 0.9 for patients with CRRT, where CL pop , V1 pop , Q pop , and V2 pop are 6.82 L/h, 40.6 L, 1 L/h, and 9.2 L respectively normalized to a 70-kg subject. Continuous infusion, 60 and 120 mg/kg per day, is the most adequate dosing regimen to attain the target of 50% fT >  MIC and 100% fT >  MIC for patients infected by bacteria with high minimum inhibitory concentration (MIC) value (> 4 mg/L) without risk of accumulation except in children with severe renal failure., Conclusion: Continuous infusion allows reaching the fT >  MIC targets safely in children with normal or increased renal clearance.

Levofloxacin, pefloxacin, ciprofloxacin and moxifloxacin are four fluoroquinolones used in the treatment of serious bacterial infections. The antibacterial activity of fluoroquinolones is concentration dependent. Therefore, therapeutic drug monitoring in daily clinical practice is warranted to ensure the therapy's efficacy and prevent bacterial resistance. The purpose of the present study was to develop a method using high-pressure liquid chromatography with an ultraviolet detector for simultaneous quantification of these four fluoroquinolones in human plasma. A 50 μL aliquot of plasma was precipitated by 200 μL of methanol using gatifloxacin as internal standard. The chromatographic separation was performed on a Kinetex XB-C 18 column using a mobile phase composed of a mixture of orthophosphoric acid 0.4% (v/v), acetonitrile and methanol at a flow rate of 1.2 mL/min. Dual UV wavelength mode was used, with levofloxacin and moxifloxacin monitored at 293 nm, and pefloxacin and ciprofloxacin monitored at 280 nm. The calibration was linear over the ranges of 0.125-25 mg/L for levofloxacin, 0.1-20mg/L for moxifloxacin and 0.05-10 mg/L for both pefloxacin and ciprofloxacin. Inter- and intra-day trueness and precision were <13% for all the compounds under study. The proposed method was simple, reliable, cost-effective and suitable for therapeutic drug monitoring or pharmacokinetics studies., (© 2019 John Wiley & Sons, Ltd.)

Valproate is an old-generation antiepileptic drug often used in children. The pharmacokinetics of valproate are noteworthy for a large and difficult to predict interindividual variability in measured serum concentrations and for saturable protein binding. A model-based approach to personalize valproate treatment could be relevant in pediatric patients. The aims of this study were to review all published valproate population pharmacokinetic models in children and assess them by external validation to determine their predictive performance. Through simulations with the best model, we evaluated dosing regimen. A validation data set included valproate serum concentrations assayed during routine therapeutic drug monitoring of epileptic children. We applied to our population 11 published pediatric population pharmacokinetic models. For each model, predictive performance was assessed by external validation, using bias and precision calculations as well as goodness-of-fit plots. Dose simulations were conducted with the best predictive model to evaluate dosing regimen. The validation data set contained 178 valproate concentrations ranging from 13.4 to 128 mg/L from 114 patients. The best model exhibited a mean prediction error of 6.6 mg/L and a root mean squared error of 25.1 mg/L, with no model misspecification evidenced by visual predictive check. In our cohort, half the patients had a trough concentration <50 mg/L. Simulations suggested increasing doses, especially for children ≤40 kg. External evaluation of published valproate pharmacokinetic models enabled us to identify a suitable model for simulations and Bayesian forecasting. Dosing regimen should be adjusted to weight, with decreasing doses with increasing weight., (© 2018, The American College of Clinical Pharmacology.)

Background: Critically ill children frequently display observed alterations of pharmacokinetic (PK) parameters, leading to a reduction in β-lactam concentrations. This study aimed to develop a PK population model for piperacillin in order to optimize individual dosing regimens., Methods: All children aged ≤ 18 years, weighing more than 2.5 kg, and receiving piperacillin infusions were included in this study. Piperacillin was quantified by high-performance liquid chromatography, and PK were described using the non-linear mixed-effect modeling software MONOLIX. Monte Carlo simulations were used to optimize dosing regimens in order to attain two PK targets: 50% fT >MIC and 100% fT >MIC ., Results: We included 50 children with a median (range) postnatal age of 2.3 years (0.1-18), body weight (BW) of 11.9 kg (2.7-50), Pediatric Logistic Organ Dysfunction-2 (PELOD-2) severity score of 4 (0-16), and estimated glomerular filtration rate (eGFR) of 142 mL.min -1 .1.73 m -2 (29-675). A one-compartment model with first-order elimination adequately described the data. Median (range) values for piperacillin clearance (CL) and volume of distribution were 3 L.h -1 (0.71-10) and 0.33 L.kg -1 (0.21-0.86), respectively. BW was integrated with the allometric relationship. eGFR and PELOD-2 severity score were the covariates explaining between-subject variability in CL and volume, respectively. According to the simulations, extended and continuous infusion provided the highest probability of reaching the target of 50% fT >MIC and 100% fT >MIC for normal and augmented renal clearance, respectively., Conclusions: Unlike standard intermittent piperacillin dosing regimens, extended and continuous infusion allows the PK targets to be reached, for children with normal or augmented renal clearance., Trial Registration Number: Registered at http://www.clinicaltrials.gov (NCT02539407).

The API triethylenetetramine dihydrochloride used as an alternative treatment of Wilson's disease is sensitive to water and it exhibits polymorphism. As this may become an issue for the drug formulation, the physical stability has been studied by differential scanning calorimetry, high-pressure thermal analysis, dynamic vapor sorption, and X-ray diffraction as a function of temperature. In addition, high-pressure liquid chromatography and mass spectrometry have been used to study the purity and chemical stability of the API. A pressure-temperature phase diagram of the pure compound has been constructed and it can be concluded that form II is monotropic in relation to form I, which is the only stable solid. The solubilities of the different solid forms have been determined with the help of a temperature - composition phase diagram. The API is very soluble, at 20° C about 10% of the saturated solution with respect to the dihydrate consists of API and the solubility of the pure form I is twice as high. Moreover, it has been shown that at 20°C, a relative humidity above 40% induces the formation of the dihydrate and at 70% a saturated solution appears. At higher temperatures, the formation of the dihydrate appears at lower relative humidity values. A clear link has been established between the API's chemical stability, its physical stability and the relative humidity in the air. Humidity levels above 40% are detrimental to the quality of the API., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Understanding the phase behavior of pharmaceuticals is important for dosage form development and regulatory requirements, in particular after the incident with ritonavir. In the present paper, a comprehensive study of the solid-state phase behavior of cysteamine hydrochloride used in the treatment of nephropathic cystinosis and recently granted orphan designation by the European Commission is presented employing (high-pressure) calorimetry, water vapor sorption, and X-ray diffraction as a function of temperature. A new crystal form (I2/a, form III) has been discovered, and its structure has been solved by X-ray powder diffraction, while two other crystalline forms are already known. The relative thermodynamic stabilities of the commercial form I and of the newly discovered form III have been established; they possess an overall enantiotropic phase relationship, with form I stable at room temperature and form III stable above 37 °C. Its melting temperature was found at 67.3 ± 0.5 °C. Cysteamine hydrochloride is hygroscopic and immediately forms a concentrated saturated solution in water with a surprisingly high concentration of 47.5 mol % above a relative humidity of 35%. No hydrate has been observed. A temperature-composition phase diagram is presented that has been obtained with the unary pressure-temperature phase diagram, measurements, and calculations. For development, form I would be the best form to use in any solid dosage form, which should be thoroughly protected against humidity.

The methomyl is increasingly involved in suicidal and autolytic attempts. Intoxication with carbamate (CM) compounds is still a frequent cause for admission in the Emergency department of the medical assistance center (MAC) in Tunis, Tunisia. The aim of this study was to describe the demographics, clinical features and hospital course of patients presenting with CM intoxication to the ED of MAC in Tunis, Tunisia. This was a retrospective study about 52 cases of acute poisoning by methomyl, compiled in the MAC from 1st January, 2009 to December 31, 2012. Intoxications were all oral, mostly intentional (33 cases: 65%) and in young patients (29 years old). Females outnumbered males by almost 2:1. The most frequent symptom was hypotension (41 cases: 80%), followed by miosis (39 cases: 75%), rhabdomyolysis (29 cases: 55%), vomiting (18 cases: 43%), bronchorrhea (14 cases: 27%), diarrhea (11 cases: 21%) and fasciculations (8 cases: 17%). Treatments included gastric lavage in 16 patients (32%), assisted ventilation in 8 cases (17%) and atropine in 44 patients (85%). Seven patients died during hospitalization. Pesticide poisoning is a significant public health problem and some preventive measures must be strictly enforced to limit this kind of intoxication.