scholarly journals Pharmacological Properties of a New Antimalarial Bisthiazolium Salt, T3, and a Corresponding Prodrug, TE3

2005 ◽  
Vol 49 (9) ◽  
pp. 3631-3639 ◽  
Author(s):  
Olivier Nicolas ◽  
Delphine Margout ◽  
Nicolas Taudon ◽  
Sharon Wein ◽  
Michèle Calas ◽  
...  
Keyword(s):  
Oral Administration ◽  
Antimalarial Activity ◽  
Plasma Concentrations ◽  
Intraperitoneal Administration ◽  
Absolute Bioavailability ◽  
Pharmacokinetic Parameters ◽  
Pharmacological Properties ◽  
Mean Values

ABSTRACT A new approach to malarial chemotherapy based on quaternary ammonium that targets membrane biogenesis during intraerythrocytic Plasmodium falciparum development has recently been developed. To increase the bioavailability, nonionic chemically modified prodrugs were synthesized. In this paper, the pharmacological properties of a bisthiazolium salt (T3) and its bioprecursor (TE3) were studied. Their antimalarial activities were determined in vitro against the growth of P. falciparum and in vivo against the growth of P. vinckei in mice. Pharmacokinetic evaluations were performed after T3 (1.3 and 3 mg/kg of body weight administered intravenously; 6.4 mg/kg administered intraperitoneally) and TE3 (1.5 and 3 mg/kg administered intravenously; 12 mg/kg administered orally) administrations to rats. After intraperitoneal administration, very low doses offer protection in a murine model of malaria (50% efficient dose [ED50] of 0.2 to 0.25 mg/kg). After oral administration, the ED50 values were 13 and 5 mg/kg for T3 and TE3, respectively. Both compounds exerted antimalarial activity in the low nanomolar range. After TE3 administration, rapid prodrug-drug conversion occurred; the mean values of the pharmacokinetic parameters for T3 were as follows: total clearance, 1 liter/h/kg; steady-state volume of distribution, 14.8 liters/kg; and elimination half-life, 12 h. After intravenous administration, T3 plasma concentrations increased in proportion to the dose. The absolute bioavailability was 72% after intraperitoneal administration (T3); it was 15% after oral administration (TE3). T3 plasma concentrations (8 nM) 24 h following oral administration of TE3 were higher than the 50% inhibitory concentrations for the most chloroquine-resistant strains of P. falciparum (6.3 nM).

scholarly journals Pharmacokinetic Profile of μSMIN Plus™, a new Micronized Diosmin Formulation, after Oral Administration in Rats

2015 ◽  
Vol 10 (9) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Rosario Russo ◽  
Angelo Mancinelli ◽  
Michele Ciccone ◽  
Fabio Terruzzi ◽  
Claudio Pisano ◽  
...  
Keyword(s):  
Oral Administration ◽  
Plasma Concentrations ◽  
Compartmental Analysis ◽  
Pharmacokinetic Profile ◽  
Pharmacokinetic Parameters ◽  
Maximum Plasma ◽  
Sprague Dawley ◽  
Time Curve ◽  
Maximum Plasma Drug Concentration

Diosmin is a naturally occurring flavonoid present in citrus fruits and other plants belonging to the Rutaceae family. It is used for the treatment of chronic venous insufficiency (CVI) for its pheblotonic and vaso-active properties, safety and tolerability as well. The aim of the current in vivo study was to investigate the pharmacokinetic profile of a branded micronized diosmin (μSMIN Plus™) compared with plain micronized diosmin in male Sprague-Dawley rats. After oral administration by gastric gavage, blood samples were collected via jugular vein catheters at regular time intervals from baseline up to 24 hours. Plasma concentrations were assessed by LC/MS. For each animal, the following pharmacokinetic parameters were calculated using a non-compartmental analysis: maximum plasma drug concentration (Cmax), time to reach Cmax (Tmax), area under the plasma concentration-time curve (AUC0-last), elimination half-life (t1/2), and relative oral bioavailability (%F). The results of the current study clearly showed an improvement in the pharmacokinetic parameters in animals treated with μSMIN Plus™ compared with animals treated with micronized diosmin. In particular, μSMIN Plus™ showed a 4-fold increased bioavailability compared with micronized diosmin. In conclusion, the results from the current study provided a preliminary pharmacokinetic profile for μSMIN Plus™, which may represent a new tool for CVI management.

Pharmacokinetics of ciclopirox prodrug, a novel agent for the treatment of bladder cancer, in animals and humans.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14705-e14705 ◽  
Author(s):  
Scott James Weir ◽  
Robyn Wood ◽  
Michael Jay Baltezor ◽  
Greg Reed ◽  
Amanda E Brinker ◽  
...  
Keyword(s):  
Phase 1 ◽  
Systemic Exposure ◽  
Absolute Bioavailability ◽  
Pharmacokinetic Parameters ◽  
Time Data ◽  
Elimination Half ◽  
Urine Drug ◽  
Ic50 Values

e14705 Background: Ciclopirox Prodrug (CPX-POM) is a novel anticancer agent currently being evaluated in patients with advanced solid tumors participating in a First-in-Human, Phase 1 safety, dose tolerance, pharmacokinetics (PK) and pharmacodynamics trial at four US sites. In vitro and in vivo preclinical proof of principle was established in high grade human urothelial cancer cell lines as well as a mouse model of bladder cancer.Methods: A series of in vivo PK studies were conducted in mice, rats and dogs to characterize the absolute bioavailability of CPX following intravenous (IV), subcutaneous (SC) and oral administration of CPX-POM. The single dose and steady-state plasma and urine pharmacokinetics of CPX-POM are also currently being characterized in patients participating in the ongoing Phase 1 trial. Plasma and urine concentrations of the prodrug and metabolites were determined by LC-MS/MS validated in each specie and matrix. Non-parametric pharmacokinetic parameters were generated from resultant plasma and urine drug and metabolite concentration-time data. Results: CPX-POM is rapidly and completely metabolized to CPX in blood via circulating phosphatases in animals and humans. CPX is completely bioavailable following IV CPX-POM administration in mice, rats and dogs. CPX and its major inactive glucuronide metabolite (CPX-G) are extensively eliminated in urine in all animal species. SC administration of CPX-POM demonstrated excellent bioavailability in rats and dogs. Following IV administration of 30-900 mg/m2CPX-POM to patients, the apparent elimination half-life of CPX ranged from 2 to 8 hours, CPX systemic exposure was dose-proportional and time-independent in cancer patients, and a major portion of the dose was eliminated as CPX-G. Conclusions: IV CPX-POM achieves plasma and urine CPX exposures that exceed in vitro IC50 values several-fold at well tolerated doses in animals and humans. CPX pharmacokinetics observed in animals were predictive of human systemic clearance based on allometric scaling. Clinical trial information: NCT03348514.

scholarly journals Celecoxib confinement within mesoporous silicon for enhanced oral bioavailability

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Feng Wang ◽  
Timothy J. Barnes ◽  
Clive A. Prestidge
Keyword(s):  
Physicochemical Characteristics ◽  
In Vitro Dissolution ◽  
Absolute Bioavailability ◽  
Dissolution Behavior ◽  
Pharmacokinetic Parameters ◽  
Mesoporous Silicon ◽  
Silicon Matrix ◽  
Oxidized Porous Silicon

AbstractWe investigate the physicochemical characteristics of celecoxib (CEL) entrapped within particles of an oxidized porous silicon matrix (pSiox); determine the oral dose response of CEL compared to pure drug and innovator formulation; develop in vivo-in vitro correlation (IVIVC). CEL was loaded into a pSiox matrix by solvent partitioning, with the physical state of the CEL characterized by FTIR, DSC, TGA and XRD, and correlated with in vitro dissolution behavior. Single dose pharmacokinetic parameters of orally dosed CEL were determined in fasted rats for aqueous suspensions of pure CEL, Celebrexr and CEL-pSiox microparticles. Physicochemical testing of CEL-pSiox formulation confirmed the entrapment of CEL within porous nanostructure in an amorphous or non-crystalline form. CEL-pSiox demonstrated superior pharmacokinetics compared with CEL particles or Celebrexr, i.e. increased absolute bioavailability (96.2% vs. 65.2% vs. 88.1%), increased C

scholarly journals Pharmacokinetic Interaction between Nevirapine and Nortriptyline in Rats: Inhibition of Nevirapine Metabolism by Nortriptyline

2014 ◽  
Vol 58 (12) ◽  
pp. 7041-7048 ◽  
Author(s):  
Iris Usach ◽  
Virginia Melis ◽  
Patricia Gandía ◽  
José-Esteban Peris
Keyword(s):  
Plasma Concentrations ◽  
Pharmacokinetic Interaction ◽  
Hepatic Metabolism ◽  
Transcriptase Inhibitor ◽  
Tricyclic Antidepressant ◽  
Pharmacokinetic Parameters ◽  
Maximum Plasma ◽  
Hepatic Microsomes

ABSTRACTOne of the most frequent comorbidities of HIV infection is depression, with a lifetime prevalence of 22 to 45%. Therefore, it was decided to study a potential pharmacokinetic interaction between the nonnucleoside reverse transcriptase inhibitor nevirapine (NVP) and the tricyclic antidepressant nortriptyline (NT). NVP and NT were administered to rats either orally, intraduodenally, or intravenously, and the changes in plasma levels and pharmacokinetic parameters were analyzed. Experiments with rat and human hepatic microsomes were carried out to evaluate the inhibitory effects of NT on NVP metabolism. NVP plasma concentrations were significantly higher when this drug was coadministered with NT. The maximum plasma concentrations of NVP were increased 2 to 5 times and the total plasma clearance was decreased 7-fold in the presence of NT. However, statistically significant differences in the pharmacokinetic parameters of NT in the absence and presence of NVP were not found.In vitrostudies with rat and human hepatic microsomes confirmed the inhibition of NVP hepatic metabolism by NT in a concentration-dependent way, with the inhibition being more intense in the case of rat microsomes. In conclusion, a pharmacokinetic interaction between NVP and NT was detected. This interaction was a consequence of the inhibition of hepatic metabolism of NVP by NT.In vivohuman studies are required to evaluate the effects of this interaction on the pharmacokinetics of NVP before it can be taken into account for patients receiving NVP.

scholarly journals Enhanced Dissolution and Oral Bioavailability of Cyclosporine A: Microspheres Based on αβ-Cyclodextrins Polymers

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 285 ◽  
Author(s):  
Malika Lahiani-Skiba ◽  
Francois Hallouard ◽  
Frederic Bounoure ◽  
Nicolas Milon ◽  
Youness Karrout ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Secondary Structure ◽  
Oral Administration ◽  
Drug Delivery System ◽  
Delivery System ◽  
Cyclosporine A ◽  
Polymer Mixture ◽  
Pharmacokinetic Parameters

Cyclosporine (CsA) has a selective property of suppressing various T-lymphocyte functions. This is of utmost importance in preventing allograft rejection by several organ transplantations, as well as in the treatment of systemic and local autoimmune disorders. However, the poor water solubility of CsA can be a major hurdle for its absorption into the blood stream, which leads to low bioavailability and thus less efficacy. The aim of this study was to prepare, characterize, and evaluate in vitro as well as in vivo, the potential of the innovative CsA drug delivery system. The latter contains CsA in spherical amorphous solid dispersion (SASD) which is embedded in an original α-cyclodextrin and β-cyclodextrin polymer mixture (Poly-αβ-CD) as a multifunctional amorphous carrier. The new developed SASD formulation showed that CsA was molecularly dispersed in αβ-cyclodextrins in an amorphous form, as was confirmed by physicochemical characterization studies. Interestingly, the peptide secondary structure, and thus, the drug activity was not impacted by the preparation of SASD as was shown by circular dichroism. Furthermore, the in vitro CsA release profile kinetics was almost identical to the commercially available product Neoral®. This study presents the first in vivo proof-of-concept for a novel drug delivery system based on Poly-αβ-CD containing CsA, with SASD allowing for increased bioavailibility. The pharmacokinetic parameters of cyclosporine A from the spherical spray-dried dispersion formulation was demonstrated in a “rat” animal model. For comparison, the commercially available Neoral® was studied. Importantly, the pharmacokinetic parameters were improved by extending Tmax from 2 to 3 h after the oral administration in rats, and eventually preventing the enterohepatic circulation. All these results clearly demonstrate the improved pharmacokinetic parameters and enhanced bioavailability of CsA in the new developed drug delivery system. These data demonstrated the superiority of the newly developed Poly-αβ-CD formulation for oral administration of the poorly soluble CsA in vivo without altering its secondary structure. Poly-αβ-CD can be a very useful tool for the oral administration of poorly water-soluble drugs.

scholarly journals Pharmacokinetic Comparison of 20(R)- and 20(S)-Ginsenoside Rh1 and 20(R)- and 20(S)-Ginsenoside Rg3 in Rat Plasma following Oral Administration of Radix Ginseng Rubra and Sheng-Mai-San Extracts

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaomei Fan ◽  
Yan Xu ◽  
Danni Zhu ◽  
Yibing Ji
Keyword(s):  
Oral Administration ◽  
Rat Plasma ◽  
Pharmacokinetic Parameters ◽  
Spectrometric Method ◽  
Pharmacokinetic Studies ◽  
Mass Spectrometric Method ◽  
Ginsenoside Rg3 ◽  
Radix Ginseng

Ginsenosides Rh1 and Rg3, as the main bioactive components from Ginseng, are effective for prevention and treatment of cardiovascular diseases. Sheng-Mai-San (SMS), a classical complex prescription of traditional Chinese medicines, is composed of Radix Ginseng Rubra, Fructus Schisandrae, and Radix Ophiopogonis. In this research, a sensitive and specific liquid chromatography-mass spectrometric method was developed and validated for stereoselective determination and pharmacokinetic studies of 20(R)- and 20(S)-ginsenoside Rh1 and 20(R)- and 20(S)-ginsenoside Rg3 epimers in rat plasma after oral administration of Radix Ginseng Rubra or SMS extracts. The main pharmacokinetic parameters including Tmax, Cmax, t1/2, and AUC were calculated by noncompartment model. Compared with Radix Ginseng Rubra, SMS could significantly increase the content of ginsenosides Rh1 and Rg3 in the decocting process. Ginsenosides Rh1 and Rg3 following SMS treatment displayed higher Cmax, AUC(0–t), and AUC0–∞ and longer t1/2 and tmax except for 20(R)-Rh1 in rat plasma. The results indicated SMS compound compatibility could influence the dissolution in vitro and the pharmacokinetic behaviors in vivo of ginsenosides Rh1 and Rg3, suggesting pharmacokinetic drug-drug interactions between ginsenosides Rh1 and Rg3 and other ingredients from Fructus Schisandrae and Radix Ophiopogonis. This study would provide valuable information for drug development and clinical application of SMS.

scholarly journals Artemisinin Therapy for Malaria in Hemoglobinopathies: A Systematic Review

2018 ◽  
Vol 66 (5) ◽  
pp. 799-804 ◽  
Author(s):  
Sri Riyati Sugiarto ◽  
Brioni R Moore ◽  
Julie Makani ◽  
Timothy M E Davis
Keyword(s):  
Clinical Studies ◽  
Antimalarial Activity ◽  
Artemisinin Combination Therapy ◽  
Plasma Concentrations ◽  
Parasite Clearance ◽  
Convincing Evidence ◽  
Hemoglobin E ◽  
Artemisinin Derivatives

Abstract Artemisinin derivatives are widely used antimalarial drugs. There is some evidence from in vitro, animal and clinical studies that hemoglobinopathies may alter their disposition and antimalarial activity. This review assesses relevant data in α-thalassemia, sickle cell disease (SCD), β-thalassemia and hemoglobin E. There is no convincing evidence that the disposition of artemisinin drugs is affected by hemoglobinopathies. Although in vitro studies indicate that Plasmodium falciparum cultured in thalassemic erythrocytes is relatively resistant to the artemisinin derivatives, mean 50% inhibitory concentrations (IC50s) are much lower than in vivo plasma concentrations after recommended treatment doses. Since IC50s are not increased in P. falciparum cultures using SCD erythrocytes, delayed post-treatment parasite clearance in SCD may reflect hyposplenism. As there have been no clinical studies suggesting that hemoglobinopathies significantly attenuate the efficacy of artemisinin combination therapy (ACT) in uncomplicated malaria, recommended artemisinin doses as part of ACT remain appropriate in this patient group.

The Role of Cytochrome P450 3A4 in Alfentanil Clearance 

1997 ◽  
Vol 87 (1) ◽  
pp. 36-50 ◽  
Author(s):  
Evan D. Kharasch ◽  
Michael Russell ◽  
Douglas Mautz ◽  
Kenneth E. Thummel ◽  
Kent L. Kunze ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Rate Constant ◽  
Human Liver ◽  
Plasma Concentrations ◽  
Time Dependent ◽  
Pharmacokinetic Parameters ◽  
Cytochrome P450 3A4 ◽  
Systemic Clearance

Background There is considerable unexplained variability in alfentanil pharmacokinetics, particularly systemic clearance. Alfentanil is extensively metabolized in vivo, and thus systemic clearance depends on hepatic biotransformation. Cytochrome P450 3A4 was previously shown to be the predominant P450 isoform responsible for human liver microsomal alfentanil metabolism in vitro. This investigation tested the hypothesis that P450 3A4 is responsible for human alfentanil metabolism and clearance in vivo. Methods Nine healthy male volunteers who provided institutionally approved written informed consent were studied in a three-way randomized crossover design. Each subject received alfentanil (20 micrograms/kg given intravenously) 30 min after midazolam (1 mg injected intravenously) on three occasions: control; high P450 3A4 activity (rifampin induction); and low P450 3A4 activity (selective inhibition by troleandomycin). Midazolam is a validated selective in vivo probe for P450 3A4 activity. Venous blood was sampled for 24 h and plasma concentrations of midazolam and alfentanil and their primary metabolites 1'-hydroxymidazolam and noralfentanil were measured by gas chromatography-mass spectrometry. Pharmacokinetic parameters were determined by two-stage analysis using both noncompartmental and three-compartment models. Results Plasma alfentanil concentration-time profiles depended significantly on P450 3A4 activity. Alfentanil noncompartmental clearance was 5.3 +/- 2.3, 14.6 +/- 3.8, and 1.1 +/- 0.5 ml.kg-1.min-1, and elimination half-life was 58 +/- 13, 35 +/- 7, and 630 +/- 374 min, respectively, in participants with normal (controls), high (rifampin), and low (troleandomycin) P450 3A4 activity (means +/- SD; P < 0.05 compared with controls). Multicompartmental modeling suggested a time-dependent inhibition-resynthesis model for troleandomycin effects on P450 3A4 activity, characterized as k10(t) = k10[1-phi e-alpha(t-tzero)], where k10(t) is the apparent time-dependent rate constant, k10 is the uninhibited rate constant, phi is the fraction of P450 3A4 inhibited, and alpha is the apparent P450 3A4 reactivation rate. Alfentanil clearance was calculated as V1 k10 for controls and men receiving rifampin, and as V1.average k10(t) for men receiving troleandomycin. This clearance was 4.9 +/- 2.1, 13.2 +/- 3.6, and 1.5 +/- 0.8 ml.kg-1.min-1, respectively, in controls and in men receiving rifampin or troleandomycin. There was a significant correlation (r = 0.97, P < 0.001) between alfentanil systemic clearance and P450 3A4 activity. Conclusions Modulation of P450 3A4 activity by rifampin and troleandomycin significantly altered alfentanil clearance and disposition. These results strongly suggest that P450 3A4 is the major isoform of P450 responsible for clinical alfentanil metabolism and clearance. This observation, combined with the known population variability in P450 3A4 activity, provides a mechanistic explanation for the interindividual variability in alfentanil disposition. Furthermore, known susceptibility of human P450 3A4 activity to induction and inhibition provides a conceptual framework for understanding and predicting clinical alfentanil drug interactions. Finally, human liver microsomal alfentanil metabolism in vitro is confirmed as an excellent model for human alfentanil metabolism in vivo.

scholarly journals Characterization of the potent in vitro and in vivo antimalarial activities of ionophore compounds.

1997 ◽  
Vol 41 (3) ◽  
pp. 523-529 ◽  
Author(s):  
C Gumila ◽  
M L Ancelin ◽  
A M Delort ◽  
G Jeminet ◽  
H J Vial
Keyword(s):  
Large Scale ◽  
Serum Proteins ◽  
Antimalarial Activity ◽  
Intraperitoneal Administration ◽  
Parasite Clearance ◽  
Parallel Increase ◽  
Gramicidin D ◽  
Monensin A

Large-scale in vitro screening of different types of ionophores previously pinpointed nine compounds that were very active and selective in vitro against Plasmodium falciparum; their in vitro and in vivo antimalarial effects were further studied. Addition of the ionophores to synchronized P. falciparum suspensions revealed that all P. falciparum stages were sensitive to the drugs. However, the schizont stages were three- to ninefold more sensitive, and 12 h was required for complete parasite clearance. Pretreatment of healthy erythrocytes with toxic doses of ionophores for 24 to 48 h showed that the activity was not due to an irreversible effect on the host erythrocyte. No preferential ionophore adsorption in infected or uninfected erythrocytes occurred. On the other hand, ionophore molecules strongly bound to serum proteins since increasing the serum concentration from 2 to 50% led to almost a 25-fold parallel increase in the ionophore 50% inhibitory concentration. Mice infected with the malaria parasites Plasmodium vinckei petteri or Plasmodium chabaudi were successfully treated with eight ionophores in a 4-day suppressive test. The 50% effective dose after intraperitoneal administration ranged from 0.4 to 4.1 mg/kg of body weight, and the therapeutic indices were about 5 for all ionophores except monensin A methyl ether, 5-bromo lasalocid A, and gramicidin D, whose therapeutic indices were 12, 18, and 344, respectively. These three compounds were found to be curative, with no recrudescence. Gramicidin D, which presented impressive antimalarial activity, requires parenteral administration, while 5-bromo lasalocid A has the major advantage of being active after oral administration. Overall, the acceptable levels of toxicity and the good in vivo therapeutic indices in the rodent model highlight the interesting potential of these ionophores for the treatment of malaria in higher animals.

scholarly journals Repurposing Heparin as Antimalarial: Evaluation of Multiple Modifications Toward In Vivo Application

Pharmaceutics ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 825 ◽  
Author(s):  
Elena Lantero ◽  
Carlos Raúl Aláez-Versón ◽  
Pilar Romero ◽  
Teresa Sierra ◽  
Xavier Fernàndez-Busquets
Keyword(s):  
Antimalarial Activity ◽  
Anticoagulant Activity ◽  
Plasma Concentrations ◽  
Resistance Evolution ◽  
Covalent Crosslinking ◽  
Initial Plasma ◽  
Mean Circulation ◽  
Different Origins

Heparin is a promising antimalarial drug due to its activity in inhibiting Plasmodium invasion of red blood cells and to the lack of resistance evolution by the parasite against it, but its potent anticoagulant activity is preventing the advance of heparin along the clinical pipeline. We have determined, in in vitro Plasmodium falciparum cultures, the antimalarial activity of heparin-derived structures of different origins and sizes, to obtain formulations having a good balance of in vitro safety (neither cytotoxic nor hemolytic), low anticoagulant activity (≤23 IU/mL according to activated partial thromboplastin time assays), and not too low antimalarial activity (IC50 at least around 100 µg/mL). This led to the selection of five chemically modified heparins according to the parameters explored, i.e., chain length, sulfation degree and position, and glycol-split, and whose in vivo toxicity indicated their safety for mice up to an intravenous dose of 320 mg/kg. The in vivo antimalarial activity of the selected formulations was poor as a consequence of their short blood half-life. The covalent crosslinking of heparin onto the surface of polyethylene glycol-containing liposomes did not affect its antimalarial activity in vitro and provided higher initial plasma concentrations, although it did not increase mean circulation time. Finding a suitable nanocarrier to impart long blood residence times to the modified heparins described here will be the next step toward new heparin-based antimalarial strategies.

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