scholarly journals Pharmacokinetic Studies of New Stimulator of Brain Cognitive Functions OSPL-502

2018 ◽  
Vol 1 (3) ◽  
pp. e00046
Author(s):  
S.A. Pukhov ◽  
V.V. Grigoriev ◽  
V.I. Kozlovskiy ◽  
A.A. Romanova ◽  
G.D. Shishko ◽  
...  
Keyword(s):  
Cognitive Functions ◽  
Maximum Concentration ◽  
Dosage Form ◽  
Clinical Investigation ◽  
Elimination Rate ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Studies ◽  
Volume Distribution ◽  
Time Curve ◽  
Brain Functions

The main pharmacokinetic parameters of a new stimulator of cognitive brain functions, OSPL – 502 have been determined: area under the concentration-time curve, elimination rate constant, half-elimination period, time to reach the maximum concentration, maximum concentration, volume distribution, total clearance and bioavailability of the dosage form. The main metabolites of the active substance of the dosage form of the new stimulator of cognitive functions OSPL – 502 have been analyzed. The data obtained predict the effects of the drug in humans relevant for further clinical investigation.

scholarly journals Pharmacokinetics of intramuscularly administered aminosidine in healthy subjects.

1997 ◽  
Vol 41 (5) ◽  
pp. 982-986 ◽  
Author(s):  
T P Kanyok ◽  
A D Killian ◽  
K A Rodvold ◽  
L H Danziger
Keyword(s):  
Healthy Subjects ◽  
Randomized Clinical Trials ◽  
Elimination Rate ◽  
Pharmacokinetic Parameters ◽  
Multiple Drug ◽  
Time Data ◽  
Time Curve ◽  
First Order ◽  
Significant Difference

Aminosidine is an older, broad-spectrum aminoglycoside antibiotic that has been shown to be effective in in vitro and animal models against multiple-drug-resistant tuberculosis and the Mycobacterium avium complex. The objective of this randomized, parallel trial was to characterize the single-dose pharmacokinetics of aminosidine sulfate in healthy subjects (eight males, eight females). Sixteen adults (mean [+/- standard deviation] age, 27.6 +/- 5.6 years) were randomly allocated to receive a single, intramuscular aminosidine sulfate injection at a dose of 12 or 15 mg/kg of body weight. Serial plasma and urine samples were collected over a 24-h period and used to determine aminosidine concentrations by high-performance liquid chromatographic assay. A one-compartment model with first-order input, first-order output, and a lag time (Tlag) and with a weighting factor of 1/y2 best described the data. Compartmental and noncompartmental pharmacokinetic parameters were estimated with the microcomputer program WinNonlin. One subject was not included (15-mg/kg group) because of the lack of sampling time data. On average, subjects attained peak concentrations of 22.4 +/- 3.2 microg/ml at 1.34 +/- 0.45 h. All subjects had plasma aminosidine concentrations below 2 microg/ml at 12 h, and all but two subjects (one in each dosing group) had undetectable plasma aminosidine concentrations at 24 h. The dose-adjusted area under the concentration-time curve from 0 h to infinity of aminosidine was identical for the 12- and 15-mg/kg groups (9.29 +/- 1.5 versus 9.29 +/- 2.2 microg x h/ml per mg/kg; P = 0.998). Similarly, no significant differences (P > 0.05) were observed between dosing groups for peak aminosidine concentration in plasma, time to peak aminosidine concentration in plasma, Tlag, apparent clearance, renal clearance, elimination rate constant, and elimination half-life. A significant difference was observed for the volume of distribution (0.35 versus 0.41 liters/kg; P = 0.037) between the 12 and 15 mg/kg dosing groups. Now that comparable pharmacokinetic profiles between dosing groups have been demonstrated, therapeutic equivalency testing via in vitro pharmacokinetic and pharmacodynamic modelling and randomized clinical trials in humans should be conducted.

scholarly journals Drug Interactions Between Dolutegravir and Artemether-Lumefantrine or Artesunate-Amodiaquine

2018 ◽  
Author(s):  
Stephen I Walimbwa ◽  
Mohammed Lamorde ◽  
Catriona Waitt ◽  
Julian Kaboggoza ◽  
Laura Else ◽  
...  
Keyword(s):  
Maximum Concentration ◽  
Geometric Mean ◽  
Compartmental Analysis ◽  
Sub Saharan Africa ◽  
Pharmacokinetic Studies ◽  
Serious Adverse Events ◽  
Time Curve ◽  
Once Daily ◽  
Trough Concentrations ◽  
Sub Saharan

ABSTRACTAcross sub-Saharan Africa, patients with HIV on antiretrovirals often get malaria and need cotreatment with artemisinin-containing therapies. We undertook two pharmacokinetic studies in healthy volunteers, using standard adult doses of artmether-lumefantrine (AL) or artesunate-amodiaquine (AS-AQ) given with 50mg once daily dolutegravir (DTG) to investigate the drug-drug interaction between artmether-lumefantrine or artesunate-amodiaquine and DTG. The DTG/artmether-lumefantrine interaction was evaluated in a two-way cross-over study and measured artemether (ARM), dihydroartemisinin (DHA), lumefantrine (LF), desbutyl-lumefantrine (DBL) over 264h. The DTG/artesunate-amodiaquine interaction was investigated using a parallel study design due to long half-life of the amodiaquine metabolite, desethylamodiaquine (DEAQ) and measured artesunate (ARS), amodiaquine (AQ), DEAQ over 624h. Non-compartmental analysis was performed, and geometric mean ratios and 90% confidence intervals generated for evaluation of both interactions. Dolutegravir did not significantly change the maximum concentration in plasma, time to maximum concentration and area under the concentration-time curve (AUC) for ARM, DHA, LF and DBL nor significantly alter AUC for ARS, DHA, AQ and DEAQ. Co-administration of dolutegravir with AL resulted in a 37% decrease in DTG trough concentrations. Co-administration of dolutegravir with AS-AQ resulted in a decrease of approximately 42% and 24% in DTG trough concentrations and AUC respectively. Study drugs were well-tolerated with no serious adverse events. Standard doses of artmether-lumefantrine and artesunate-amodiaquine should be used in patients receiving DTG. The significant decreases in DTG trough concentrations with artemether-lumefantrine and artesunate-amodiaquine and DTG exposure with artesunate-amodiaquine are unlikely to be of clinical significance as DTG trough concentrations were above DTG target concentrations of 64ng/mL.

Limited Sampling Strategies to Estimate the Area under the Concentration-time Curve

2012 ◽  
Vol 51 (05) ◽  
pp. 383-394 ◽  
Author(s):  
M. Fukumoto ◽  
L. Bax ◽  
A. Kohno ◽  
Y. Morishita ◽  
H. Tsuruta
Keyword(s):  
Rate Constant ◽  
Elimination Rate ◽  
Estimation Method ◽  
Pharmacokinetic Parameters ◽  
Good Precision ◽  
Sampling Strategies ◽  
Time Curve ◽  
New Methods ◽  
Limited Sampling ◽  
Concentration Time

SummaryBackground: Over 100 limited sampling strategies (LSSs) have been proposed to reduce the number of blood samples necessary to estimate the area under the concentration-time curve (AUC). The conditions under which these strategies succeed or fail remain to be clarified.Objectives: We investigated the accuracy of existing LSSs both theoretically and numerically by Monte Carlo simulation. We also proposed two new methods for more accurate AUC estimations.Methods: We evaluated the following existing methods theoretically: i) nonlinear curve fitting algorithm (NLF), ii) the trapezium rule with exponential curve approximation (TZE), and iii) multiple linear regression (MLR). Taking busulfan (BU) as a test drug, we generated a set of theoretical concentration-time curves based on the identified distribution of pharmacokinetic parameters of BU and re-evaluated the existing LSSs using these virtual validation profiles. Based on the evaluation results, we improved the TZE so that unrealistic parameter values were not used. We also proposed a new estimation method in which the most likely curve was selected from a set of pre-generated theoretical concentration-time curves.Results: Our evaluation, based on clinical profiles and a virtual validation set, revealed: i) NLF sometimes overestimated the absorption rate constant Ka, ii) TZE overestimated AUC over 280% when Ka is small, and iii) MLR underestimated AUC over 30% when the elimination rate constant Ke is small. These results were consistent with our mathematical evaluations for these methods. In contrast, our two new methods had little bias and good precision.Conclusions: Our investigation revealed that existing LSSs induce different but specific biases in the estimation of AUC. Our two new LSSs, a modified TZE and one using model concentration-time curves, provided accurate and precise estimations of AUC.

scholarly journals PHARMACOKINETIC STUDIES OF A CHRONOTHERAPEUTIC DRUG DELIVERY SYSTEM OF LORNOXICAM BY LC-MS/MS METHOD

2018 ◽  
Vol 10 (6) ◽  
pp. 88
Author(s):  
Sindhu Abraham ◽  
Rajamanickam Deveswaran ◽  
Jayaraman Anbu ◽  
Sharon Furtado ◽  
Bharath Srinivasan
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Maximum Concentration ◽  
Area Under The Curve ◽  
Immediate Release ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Studies ◽  
Elimination Half ◽  
Coated Tablet ◽  
Liquid Chromatography Tandem Mass

Objective: The objective of this study was to investigate differences in pharmacokinetic patterns of immediate release tablet (IR) and compression coated tablet (CCT) of lornoxicam, proposed for the chronotherapeutic treatment of rheumatoid arthritis.Methods: The dosage forms were administered to two groups of white New Zealand rabbits (n=3), and the plasma drug levels were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Pharmacokinetic parameters like maximum concentration (Cmax), time is taken to reach maximum concentration (Tmax), area under the curve (AUC), elimination half-life (t1/2) and Mean Residence Time (MRT) were determined.Results: In the case of IR tablets, the drug was detected within 15 min after oral administration and a Cmax of 1269.57±4.04 ng/ml were attained at 2±0.15 h. With CCT, the drug was detected only after 5 h and a Cmax of 1279.24±12.76 ng/ml were attained at 8±0.10 h. The CCT showed maximum drug release at the eighth hour in comparison to IR tablet which showed maximum release at the second hour of study.Conclusion: The predominant lag time prior to drug release from CCT is an indication that it is consistent with the requirements of chronopharmaceutical drug delivery. The results suggest that the compression coated tablet is a promising approach for chronotherapeutic management of rheumatoid arthritis.

scholarly journals Comparative in vivo study of pure drug and fast dissolving tablets of Simvastatin

2019 ◽  
Vol 9 (4-A) ◽  
pp. 490-496
Author(s):  
M. Suresh Babu ◽  
T. E. Gopalakrishna Murthy
Keyword(s):  
Rate Constant ◽  
Plasma Levels ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Elimination Rate ◽  
In Vivo Studies ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Studies ◽  
Pure Drug

The objective of this study was to investigate differences in the pharmacokinetic patterns between pure drug and an optimized  formulation of fast dissolving tablets  of Simvastatin. The formulations were administered to 2 groups of white New Zealand rabbits (n=6) following cross over design pattern and the plasma levels were measured using LC-MS/MS method. Pharmacokinetic parameters were determined for each formulation. The comparison of the plasma time curves of the dosage forms showed that each dosage form caused significant differences in the drug plasma levels.  The highest mean Cmax value was observed for optimized fast dissolving tablets (68.33 ± 0.42ng/ml) compared to  pure drug (27.72 ± 0.31ng/ml). The mean time taken to peak plasma concentration for (Tmax) following administration of pure drug  was  11.53 ± 0.011hours, while it was 6.09 ± 0.072 hour following administration of selected optimized fast dissolving tablets.The elimination rate constant (Kel) for pure drug and optimized fast dissolving tablets were found to be 0.58 ± 0.012h-1and 0.53 ± 0.014 h-1 respectively.  The absorption rate constant (Ka) for pure drug and optimized fast dissolving tablets were found to be 1.68 ± 0.01h-1and 5.53 ± 0.02h-1 respectively. The AUC0-αvalues observed with optimized fast dissolving tablets686.1.±2.07 nghr/ml in compared to pure drug values 191 ± 1.43 nghr/ml. Thus, the results of pharmacokinetic studies indicated rapid and higher oral absorption of Simvastatin when administered as its fast dissolving tablets. Both Ka and AUC were markedly increased by fast dissolving tablets. Keywords: LC-MS/MS, Simvastatin, fast dissolving, In-vivo studies, pharmacokinetic parameters.

scholarly journals Analysis of Pharmacokinetic Parameters of Acetylsalicylic Acid for Prediction of Potential Nephrotoxic Effects

2021 ◽  
Vol 9 (4) ◽  
pp. 209-215
Author(s):  
L. M. Krasnykh ◽  
O. A. Goroshko ◽  
G. F. Vasilenko ◽  
G. I. Gorodetskaya ◽  
V. V. Smirnov ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Acetylsalicylic Acid ◽  
Blood Plasma ◽  
Maximum Concentration ◽  
Test Procedure ◽  
Elimination Rate ◽  
Statistical Processing ◽  
Apparent Volume ◽  
Pharmacokinetic Parameters ◽  
In Blood Plasma

Nonsteroidal anti-inflammatory drugs, including acetylsalicylic acid, can have a dose-dependent nephrotoxic effect. The study of the pharmacokinetics of acetylsalicylic acid products will contribute to timely detection and correction of side effects caused by this medicinal product.The aim of the study was to evaluate potential nephrotoxic effects following a single oral administration of 75 mg of acetylsalicylic acid, based on the analysis of the pharmacokinetic parameters.Materials and methods: the study involved 24 healthy volunteers who received 75 mg of acetylsalicylic acid (tablets) once orally. The measurement of the active metabolite of acetylsalicylic acid—salicylic acid—in blood plasma was performed by HPLC/MS using an Agilent 1200 liquid chromatography system coupled to an Agilent 6140 tandem mass spectrometer. Agilent Eclipse XDB-C18 column (4.6 mm×150 mm; 5.0 μm) was used for chromatographic separation. The test procedure used in the study was validated. The results obtained were used to calculate the pharmacokinetic parameters: Cmax (maximum concentration), Tmax (time to maximum concentration), T1/2 (half-life of the drug), AUC0-t (area under the pharmacokinetic curve from 0 to the last time point of the curve), AUC0-∞ (total area under the pharmacokinetic curve from 0 to ∞), MRT (mean residence time of the drug in the blood), Kel (elimination rate constant), Cl/F (total clearance), Vd/F (apparent volume of distribution). The Statistics (22.0.0.0) software was used for statistical processing of the results.Results: T1/2 of salicylic acid in blood plasma was determined to be 1.6 ± 0.5 h, Cmax was 4523.0 ± 725.0 ng/mL, and Tmax was 0.98 ± 0.4 h. AUC0–t was equal to 16183.0 ± 3823.0 ng×h/m, Vd/F was 12.0 ± 3.1 L/kg, and MRT was 2.9 ± 0.6 h.Conclusions: the analysis of the pharmacokinetic parameters demonstrated a high absorption rate, intensive distribution, and moderate elimination rate of salicylic acid (the main metabolite of acetylsalicylic acid), indicating a low risk of nephrotoxic effects associated with the studied dose of the drug.

scholarly journals Drug Interactions between Dolutegravir and Artemether-Lumefantrine or Artesunate-Amodiaquine

2018 ◽  
Vol 63 (2) ◽  
pp. e01310-18 ◽  
Author(s):  
Stephen I. Walimbwa ◽  
Mohammed Lamorde ◽  
Catriona Waitt ◽  
Julian Kaboggoza ◽  
Laura Else ◽  
...  
Keyword(s):  
Maximum Concentration ◽  
Geometric Mean ◽  
Sub Saharan Africa ◽  
Pharmacokinetic Studies ◽  
Noncompartmental Analysis ◽  
Serious Adverse Events ◽  
Time Curve ◽  
Once Daily ◽  
Trough Concentrations ◽  
Sub Saharan

ABSTRACT Across sub-Saharan Africa, patients with HIV on antiretrovirals often get malaria and need cotreatment with artemisinin-containing therapies. We undertook two pharmacokinetic studies in healthy volunteers, using standard adult doses of artemether-lumefantrine or artesunate-amodiaquine given with 50 mg once daily dolutegravir (DTG) to investigate the drug-drug interaction between artemether-lumefantrine or artesunate-amodiaquine and dolutegravir. The dolutegravir/artemether-lumefantrine interaction was evaluated in a two-way crossover study and measured artemether, dihydroartemisinin, lumefantrine, and desbutyl-lumefantrine over 264 h. The dolutegravir/artesunate-amodiaquine interaction was investigated using a parallel study design due to long half-life of the amodiaquine metabolite, desethylamodiaquine and measured artesunate, amodiaquine, and desethylamodiaquine over 624 h. Noncompartmental analysis was performed, and geometric mean ratios and 90% confidence intervals were generated for evaluation of both interactions. Dolutegravir did not significantly change the maximum concentration in plasma, the time to maximum concentration, and the area under the concentration-time curve (AUC) for artemether, dihydroartemisinin, lumefantrine, and desbutyl-lumefantrine, nor did it significantly alter the AUC for artesunate, dihydroartemisinin, amodiaquine, and desethylamodiaquine. Coadministration of dolutegravir with artemether-lumefantrine resulted in a 37% decrease in DTG trough concentrations. Coadministration of dolutegravir with artesunate-amodiaquine resulted in 42 and 24% approximate decreases in the DTG trough concentrations and the AUC, respectively. The significant decreases in DTG trough concentrations with artemether-lumefantrine and artesunate-amodiaquine and dolutegravir exposure with artesunate-amodiaquine are unlikely to be of clinical significance since the DTG trough concentrations were above dolutegravir target concentrations of 300 ng/ml. Study drugs were well tolerated with no serious adverse events. Standard doses of artemether-lumefantrine and artesunate-amodiaquine should be used in patients receiving dolutegravir. (This study has been registered at ClinicalTrials.gov under identifier NCT02242799.)

The relationship of vancomycin 24-hour AUC and trough concentration

2021 ◽  
Author(s):  
David E Nix ◽  
Lisa E Davis ◽  
Kathryn R Matthias
Keyword(s):  
Trough Concentration ◽  
Elimination Rate ◽  
Compartment Model ◽  
Patient Specific ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Dosing Interval ◽  
Trough Concentrations ◽  
Relationship Of ◽  
The Relationship

Abstract Disclaimer In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose Prior to the 2020 release of a joint consensus guideline on monitoring of vancomycin therapy for serious methicillin-resistant Staphylococcus aureus (MRSA) infections, clinicians had escalated vancomycin doses for 2 decades while targeting trough concentrations of 15 to 20 µg/mL, leading to an increased frequency of nephrotoxicity. For MRSA infections, the 2020 guideline recommends adjusting doses to achieve a 24-hour area under the concentration-time curve (AUC) of 400 to 600 µg · h/mL; however, monitoring of trough concentrations has been entrenched for 3 decades. Calculating dose regimens based on AUC will require obtaining an increased number of vancomycin serum concentrations and, possibly, advanced software. The aim of this investigation was to determine the relationship between AUC and trough concentration and the influence of dosing regimen on goal achievement. Methods The relationship between trough concentration and AUC was explored through derivation of an equation based on a 1-compartment model and simulations. Results 24-hour AUC is related to dosing interval divided by half-life in a nonlinear fashion. The target trough concentration can be individualized to achieve a desired AUC range, and limiting use of large doses (>15-20 mg/kg) can protect against excessive 24-hour AUC with trough-only monitoring. Conclusion After initially determining pharmacokinetic parameters, subsequent monitoring of AUC can be accomplished using trough concentrations only. Trough concentration may be used as a surrogate for AUC, although the acceptable target trough concentration will vary depending on dosing interval and elimination rate constant. This work included development of an AUC-trough equation to establish a patient-specific target for steady-state trough concentration.

scholarly journals Pharmacokinetics of Single-Dose Daptomycin in Patients with Suspected or Confirmed Neurological Infections

2011 ◽  
Vol 55 (7) ◽  
pp. 3505-3509 ◽  
Author(s):  
Ravina Kullar ◽  
Judy N. Chin ◽  
David J. Edwards ◽  
Dennis Parker ◽  
William M. Coplin ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Human Subjects ◽  
Pharmacokinetic Parameters ◽  
Published Data ◽  
Pharmacokinetic Studies ◽  
Csf Shunts ◽  
Time Curve ◽  
Csf Penetration ◽  
Neurosurgical Patients ◽  
The Mean

ABSTRACTThere are currently few or no published data on the amount of cerebrospinal fluid (CSF) penetration of daptomycin in patients with suspected or documented neurosurgical infections. We conducted a prospective study, assessing the pharmacokinetics and CSF penetration of a single intravenous daptomycin dose administered at 10 mg/kg, based on total body weight (TBW), in six neurosurgical patients with indwelling external CSF shunts with suspected or documented meningitis or ventriculitis. Each patient had four blood and CSF samples drawn simultaneously at specific times after the end of infusion: 30 min, 6 h, 12 h, and 24 h. Pharmacokinetic parameters of daptomycin in serum were calculated using standard noncompartmental methods, and daptomycin was assayed using high-performance liquid chromatography (for serum) or liquid chromatography with mass spectrometry (for CSF). The mean (± standard deviation [SD]) maximum measured daptomycin concentrations were 93.7 ± 17.3 mg/liter in serum at 0.5 h postinfusion and 0.461 ± 0.51 mg/liter in CSF at 6 h postinfusion. The mean (± SD) daptomycin minimum concentrations were 13.8 ± 4.8 mg/liter in serum at 24 h postinfusion and 0.126 ± 0.12 mg/liter in CSF at 0.5 h postinfusion. The mean daptomycin penetration, determined by the area under the concentration-time curve in CSF (AUCCSF)/(AUCserumratio), was 0.8%. Corrected for protein binding, the overall CSF penetration was 11.5%. Additional pharmacokinetic studies evaluating multiple and/or higher dosages of daptomycin are necessary in human subjects to better characterize the CSF penetration of daptomycin in neurosurgical patients.

scholarly journals Effects of Silymarin on the In Vivo Pharmacokinetics of Simvastatin and Its Active Metabolite in Rats

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1666
Author(s):  
Ying Li ◽  
Yin Wu ◽  
Ya-Jing Li ◽  
Lu Meng ◽  
Cong-Yang Ding ◽  
...  
Keyword(s):  
Active Metabolite ◽  
Compartmental Model ◽  
Elimination Rate ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Simultaneous Quantification ◽  
Concentration Time ◽  
Significant Difference ◽  
In Vivo Pharmacokinetics

Herein, the effect of silymarin pretreatment on the pharmacokinetics of simvastatin in rats was evaluated. To ensure the accuracy of the results, a rapid and sensitive UPLC–MS/MS method was established for simultaneous quantification of simvastatin (SV) and its active metabolite simvastatin acid (SVA). This method was applied for studying the pharmacokinetic interactions in rats after oral co-administration of silymarin (45 mg/kg) and different concentrations of SV. The major pharmacokinetic parameters, including Cmax, tmax, t1/2, mean residence time (MRT), elimination rate constant (λz) and area under the concentration-time curve (AUC0–12h), were calculated using the non-compartmental model. The results showed that the co-administration of silymarin and SV significantly increased the Cmax and AUC0–12h of SVA compared with SV alone, while there was no significant difference with regards to Tmax and t1/2. However, SV pharmacokinetic parameters were not significantly affected by silymarin pretreatment. Therefore, these changes indicated that drug-drug interactions may occur after co-administration of silymarin and SV.

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