scholarly journals Changes in Rosuvastatin Pharmacokinetics During Postnatal Ontogenesis in Rats

2021 ◽  
Vol 25 ◽  
pp. 1-8
Author(s):  
Jaroslava Roušarová ◽  
Martin Šíma ◽  
Petr Kozlík ◽  
Tomáš Křížek ◽  
Ondřej Slanař
Keyword(s):  
Drug Exposure ◽  
Case Reports ◽  
Age Groups ◽  
Clinical Development ◽  
Developmental Changes ◽  
Pharmacokinetic Parameters ◽  
Interspecies Scaling ◽  
Total Drug ◽  
Intraperitoneal Dose

Purpose: Statin therapy should be considered in children with familial hypercholesterolemia and sustained high LDL-C levels. There are no data on rosuvastatin exposure in patients <6 years and efficacy/safety can only be derived from case reports. Our aim was to examine developmental changes in pharmacokinetics of rosuvastatin in rats in vivo as a basis for clinical development of formulations for patients < 6 years. Methods: Rosuvastatin pharmacokinetics was examined in rats aged 1, 4, 7, 10, 14, 21, 28, 35 and 42 days (from birth to sexual maturity). After intraperitoneal dose of 5 mg/kg, blood samples to determine serum rosuvastatin levels were taken at 0.5, 3 and 5 hours. Pharmacokinetic parameters (Vd, CL, AUClast, AUC0-∞) were calculated using pharmacokinecic simulations. Results: Both rosuvastatin CL and Vd started to increase systematically between 2 - 3 weeks of age, which was reflected by decreased total drug exposure. The AUC was up to 13 times higher in the age groups ≤14 days compared with the value at 42 days. Conclusions: Based on interspecies scaling, a dose reduction could be a feasible way, how to develop appropriate dosing schedule and formulations for children aged 2 - 6 years. However, confirmation in clinical development studies will be needed.

scholarly journals In Vivo Evaluation of Dual-Targeted Nanoparticles Encapsulating Paclitaxel and Everolimus

Cancers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 752 ◽  
Author(s):  
Loujin Houdaihed ◽  
James Christopher Evans ◽  
Christine Allen
Keyword(s):  
Drug Combination ◽  
Drug Exposure ◽  
Area Under The Curve ◽  
Growth Factor Receptor ◽  
Body Weight Loss ◽  
Free Drug ◽  
Equivalent Dose ◽  
Pharmacokinetic Parameters ◽  
In Vivo Evaluation

A synergistic combination of paclitaxel (PTX) and everolimus (EVER) can allow for lower drug doses, reducing the toxicities associated with PTX, while maintaining therapeutic efficacy. Polymeric nanoparticles (NPs) of high stability provide opportunities to modify the toxicity profile of the drugs by ensuring their delivery to the tumor site at the synergistic ratio while limiting systemic drug exposure and the toxicities that result. The goal of the current study is to evaluate the in vivo fate of human epidermal factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR) dual-targeted PTX+EVER-loaded NPs (Dual-NPs) in an MDA-MB-231-H2N breast cancer (BC) tumor-bearing mouse model. The pharmacokinetic parameters, plasma area under the curve (AUC) and half-life (t1/2z) were found to be 20-fold and 3 to 4-fold higher, respectively, for the drugs when administered in the Dual-NPs in comparison to the free-drug combination (i.e., PTX+EVER) at an equivalent dose of PTX. While maintaining anti-tumor efficacy, the levels of body weight loss were significantly lower (p < 0.0001) and the overall degree of neurotoxicity was reduced with Dual-NPs treatment in comparison to the free-drug combination when administered at an equivalent dose of PTX. This study suggests that Dual-NPs present a promising platform for the delivery of the PTX and EVER combination with the potential to reduce severe PTX-induced toxicities and in turn, improve quality of life for patients with BC.

scholarly journals Pharmacokinetic profile of amodiaquine and its active metabolite desethylamodiaquine in Ghanaian patients with uncomplicated falciparum malaria

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Thomas A. Anyorigiya ◽  
Sandra Castel ◽  
Katya Mauff ◽  
Frank Atuguba ◽  
Bernhards Ogutu ◽  
...  
Keyword(s):  
Falciparum Malaria ◽  
Active Metabolite ◽  
Drug Exposure ◽  
Age Groups ◽  
Uncomplicated Falciparum Malaria ◽  
Fixed Dose ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Close Monitoring ◽  
Drug Concentrations

Abstract Background Accurate measurement of anti-malarial drug concentrations in therapeutic efficacy studies is essential to distinguish between inadequate drug exposure and anti-malarial drug resistance, and to inform optimal anti-malarial dosing in key target population groups. Methods A sensitive and selective LC–MS/MS method was developed and validated for the simultaneous determination of amodiaquine and its active metabolite, desethylamodiaquine, and used to describe their pharmacokinetic parameters in Ghanaian patients with uncomplicated falciparum malaria treated with the fixed-dose combination, artesunate-amodiaquine. Results The day-28 genotype-adjusted adequate clinical and parasitological response rate in 308 patients studied was > 97% by both intention-to-treat and per-protocol analysis. After excluding 64 patients with quantifiable amodiaquine concentrations pre-treatment and 17 with too few quantifiable concentrations, the pharmacokinetic analysis included 227 patients (9 infants, 127 aged 1–4 years, 91 aged ≥ 5 years). Increased median day-3 amodiaquine concentrations were associated with a lower risk of treatment failure [HR 0.87 (95% CI 0.78–0.98), p = 0.021]. Amodiaquine exposure (median AUC0-∞) was significantly higher in infants (4201 ng h/mL) and children aged 1–5 years (1994 ng h/mL) compared to older children and adults (875 ng h/mL, p = 0.001), even though infants received a lower mg/kg amodiaquine dose (median 25.3 versus 33.8 mg/kg in older patients). Desethylamodiaquine AUC0-∞ was not significantly associated with age. No significant safety concerns were identified. Conclusions Efficacy of artesunate-amodiaquine at currently recommended dosage regimens was high across all age groups. Reassuringly, amodiaquine and desethylamodiaquine exposure was not reduced in underweight-for-age young children or those with high parasitaemia, two of the most vulnerable target populations. A larger pharmacokinetic study with close monitoring of safety, including full blood counts and liver function tests, is needed to confirm the higher amodiaquine exposure in infants, understand any safety implications and assess whether dose optimization in this vulnerable, understudied population is needed.

Mathematical Examination of Dual Individualization Principles (II): The Rate of Bacterial Eradication at the Same Area under the Inhibitory Curve is More Rapid for Ciprofloxacin Than for Cefmenoxime

1994 ◽  
Vol 28 (7-8) ◽  
pp. 863-868 ◽  
Author(s):  
Thomas F. Goss ◽  
Alan Forrest ◽  
David E. Nix ◽  
Charles H. Ballow ◽  
Mary C. Birmingham ◽  
...  
Keyword(s):  
Nosocomial Pneumonia ◽  
Drug Exposure ◽  
Tracheal Aspirate ◽  
Generation Cephalosporin ◽  
Pharmacokinetic Parameters ◽  
Bacterial Eradication ◽  
Serum Samples ◽  
Bacterial Killing

OBJECTIVE: To compare two antibiotics at equal ranges of area under the inhibitory curve (AUIC) exposure to determine if the rate of bacterial eradication differed between these antibiotics. DESIGN: Retrospective comparison of two previously collected studies of similar patients with nosocomial pneumonia. SETTING: Hospitalized patients, most intubated in critical care units with nosocomial pneumonia. PARTICIPANTS: Patients treated with either iv ciprofloxacin (n=74) or the iv third-generation cephalosporin cefmenoxime (n=43) were compared for their length of treatment required to eradicate bacterial pathogens from their respective infection sites, using serial cultures from the site of infection. All patients were also assessed for clinical outcomes. Serum samples were obtained to evaluate individual patient antibiotic pharmacokinetics, which were used to model pharmacodynamics of response. The HPLC assay used for each antibiotic had interday coefficients of variation <10 percent. Serum concentration versus time profiles were fit using the computer program ADAPT II to determine pharmacokinetic parameters for each patient. The primary drug exposure measure that related to response was the AUIC, calculated as steady-state AUC0–24/minimum inhibitory concentration. RESULTS: AUIC values in the patients ranged from 6.0 to more than 7000, yet the AUIC value was highly predictive of time to bacterial eradication (p<0.OO 1). Although more than 75 percent of patients eventually achieved eradication of pathogens from tracheal aspirate cultures, ciprofloxacin and cefmenoxime differed significantly in the time required to sterilize these cultures. At appropriate AUIC values (>250) for ciprofloxacin, the median time to eradication was two days, while cefmenoxime (also at AUIC values >250) required six days to achieve the same result. CONCLUSIONS: We conclude that the more rapid in vitro bacterial killing, which is characteristic of ciprofloxacin at optimal AUIC values, can manifest in vivo as more rapid clearance of bacteria from the respiratory tract of patients, even when both agents are controlled for initial antibacterial exposure (i.e., same AUIC).

A Multicenter Study of Recombinant Factor VIII (RecombinateTM) in Previously Treated Patients with Hemophilia A

1997 ◽  
Vol 77 (04) ◽  
pp. 660-667 ◽  
Author(s):  
G C White ◽  
S Courter ◽  
G L Bray ◽  
M Lee ◽  
E D Gomperts ◽  
...  
Keyword(s):  
Hemophilia A ◽  
Recombinant Dna ◽  
Home Treatment ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Studies ◽  
Open Label ◽  
Treat Ment ◽  
Previously Treated Patients ◽  
Bleeding Episodes

SummaryA prospective, open-label multicenter investigation has been conducted to compare pharmacokinetic parameters of recombinant DNA-derived FVIII (rFVIII) and plasma-derived FVIII concentrate (pdFVIII) and to assess safety and efficacy of long-term home-treat- ment with rFVIII for subjects with hemophilia A. Following comparative in vivo pharmacokinetic studies, 69 patients with severe (n = 67) or moderate (n = 2) hemophilia A commenced a program of home treatment using rFVIII exclusively for prophylaxis and treatment of all bleeding episodes for a period of 1.0 to 5.7 years (median 3.7 years). The mean in vivo half-lives of rFVIII and pdFVIII were both 14.7 h. In vivo incremental recoveries at baseline were 2.40%/IU/kg and 2.47%/IU/kg, respectively (p = 0.59). The response to home treatment with rFVIII was categorized as good or excellent in 3,195 (91.2%) of 3,481 evaluated bleeding episodes. Thirteen patients received rFVIII for prophylaxis for twenty-four surgical procedures. In all cases, hemostasis was excellent. Adverse reactions were observed in only 13 of 13,591 (0.096%) infusions of rFVIII; none was serious. No patient developed an inhibitor to r FVIII.

Formulation and Evaluation of Nanosuspension of Simvastatin

2015 ◽  
Vol 8 (2) ◽  
pp. 2858-2873
Author(s):  
Rupali L. Shid ◽  
Shashikant N. Dhole ◽  
Nilesh Kulkarni ◽  
Santosh L Shid
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Factorial Design ◽  
Dissolution Rate ◽  
In Vitro Dissolution ◽  
Total Drug ◽  
23 Factorial Design ◽  
Rate Of Dissolution

Poor water solubility and slow dissolution rate are issues for the majority of upcoming and existing biologically active compounds. Simvastatin is poorly water-soluble drug and its bioavailability is very low from its crystalline form. The purpose of this study wasto increase the solubility and dissolution rate of simvastatin by the  preparation of nanosuspension by emulsification solvent diffusion method at laboratory scale. Prepared nanosus-pension was evaluated for its particle size and in vitro dissolution study and characterized by zeta potential,differential scanning calorimetry (DSC) and X-Ray diffractometry (XRD), motic digital microscopy, entrapment efficiency, total drug content, saturated solubility study and in vivo study. A 23 factorial design was employed to study the effect of independent variables, amount of SLS (X1), amount of PVPK-30 (X2) and poloxamer-188 (X3) and dependent variables are total drug content and polydispersity Index. The obtained results showed that particle size (nm) and rate of dissolution has been improved when nanosuspension prepared with the higherconcentration of PVPK-30 with the higher concentration of PVP K-30 and Poloxamer-188 and lower concentration of SLS. The particle size and zeta potential of optimized formulation was found to be 258.3 nm and 23.43. The rate of dissolution of the optimized nanosuspension was enhanced (90% in 60min), relative to plain simvastatin  (21% in 60 min), mainly due to the formation of nanosized particles. These results indicate the suitability of 23 factorial  design for preparation of simvastatin loaded nano-suspension significantly improved in vitro dissolution rate and thus possibly enhance fast onset of therapeutic drug effect. In vivo study shows increase in bioavailability in nanosuspension formulation than the plain simvastatin drug.

Cationic Diclofenac Lipid Nanoemulsion for Improved Oral Bioavailability: Preparation, Characterization and In Vivo Evaluation

2015 ◽  
Vol 8 (2) ◽  
pp. 2874-2880
Author(s):  
Kishan Veerabrahma ◽  
Swapna Madishetty ◽  
Muzammil Afzal Syed ◽  
Prabhakar Kandadi
Keyword(s):  
Oral Bioavailability ◽  
Physical Stability ◽  
Cationic Lipid ◽  
Entrapment Efficiency ◽  
In Vivo Studies ◽  
Pharmacokinetic Parameters ◽  
In Vivo Evaluation ◽  
Drug Content ◽  
Lipid Nanoemulsion

Cationic nanoemulsions were reported to have increased bioavailability. The aim of present study was to prepare a cationic lipid nanoemulsion of diclofenac acid (LNEs) for improved oral bioavailability to treat arthritic conditions. The LNEs of diclofenac acid were prepared by using soya bean oil, egg lecithin, cholesterol and stearylamine. Stearylamine was used as positive charge inducer. The LNEs were processed by homogenization and ultrasonication. The formulation composition was selected based on earlier reports. The LNEs were characterized for size and zeta potential. The physical stability of LNEs was studied using autoclaving, centrifugal, desorption (dilution effect) stresses and on storage. The total drug content and entrapment efficiency were determined using HPLC. During in vivo studies in Wistar rats, the pharmacokinetic parameters of LNEs were compared with a prepared diclofenac suspension in sodium CMC mucilage. The selected formulations, F1, F2 and F3, were relatively stable during centrifugal stress, dilution stress and on storage. The drug content was found to be 2.38 ± 1.70 mg/ml for F1, 2.30 ± 0.82 mg/ml for F2, and 2.45 ± 0.66 mg/ml for F3. The entrapment efficiencies were 97.83 ± 0.53%, 97.87 ± 1.22% and 98.25 ± 0.21% for F1, F2 and F3 respectively. The cumulative percentage drug release from F1, F2 and F3 showed more release in pH 6.8 phosphate buffer than in pH 1.2 HCl. During oral bioavailability studies, the LNEs showed higher serum concentrations than a suspension. The relative bioavailability of the LNE formulations F1, F2 and F3 were found to be 2.35, 2.94 and 6.28 times that of F4 suspension and were statistically significant. Of all, the cationic lipid nanoemulsion (F3) was superior in improving bioavailability, when compared with plain emulsion (F1) and cholesterol containing LNE (F2). The study helps in designing the cationic oral nanoemulsions to improve the oral bioavailability of diclofenac.

Methodological Approaches to Evaluate Fetal Drug Exposure

2019 ◽  
Vol 25 (5) ◽  
pp. 496-504 ◽  
Author(s):  
Naïm Bouazza ◽  
Frantz Foissac ◽  
Déborah Hirt ◽  
Saïk Urien ◽  
Sihem Benaboud ◽  
...  
Keyword(s):  
Cord Blood ◽  
Drug Exposure ◽  
Placental Transfer ◽  
Ex Vivo ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Pbpk Models ◽  
Drug Concentrations ◽  
Fetal Drug Exposure

Background: Drug prescriptions are usual during pregnancy, however, women and their fetuses still remain an orphan population with regard to drugs efficacy and safety. Most xenobiotics diffuse through the placenta and some of them can alter fetus development resulting in structural abnormalities, growth or functional deficiencies. Methods: To summarize the different methodologies developed towards the prediction of fetal drug exposure. Results: Neonatal cord blood concentration is the most specific measurement of the transplacental drug transfer at the end of pregnancy. Using the cord blood and mother drug concentrations altogether, drug exchanges between the mother and fetus can be modeled and quantified via a population pharmacokinetic analysis. Thereafter, it is possible to estimate the fetus exposure and the fetus-to-mother exposure ratio. However, the prediction of placental transfer before any administration to pregnant women is desirable. Animal studies remain difficult to interpret due to structural and functional inter-species placenta differences. The ex-vivo perfusion of the human placental cotyledon is the method of reference to study the human placental transfer of drugs because it is thought to mimic the functional placental tissue. However, extrapolation of data to in vivo situation remains difficult. Some research groups have extensively worked on physiologically based models (PBPK) to predict fetal drug exposure and showed very encouraging results. Conclusion: PBPK models appeared to be a very promising tool in order to predict fetal drug exposure in-silico. However, these models mainly picture the end of pregnancy and knowledge regarding both, development of the placental permeability and transporters is strongly needed.

Metabolism and Distribution of Novel Tumor Targeting Drugs In Vivo

2020 ◽  
Vol 21 (13) ◽  
pp. 996-1008
Author(s):  
Mengli Wang ◽  
Qiuzheng Du ◽  
Lihua Zuo ◽  
Peng Xue ◽  
Chao Lan ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Small Molecule ◽  
High Efficiency ◽  
Tumor Therapy ◽  
Research Progress ◽  
Future Research ◽  
Pharmacokinetic Parameters ◽  
Molecular Characteristics ◽  
Targeted Drugs

Background: As a new tumor therapy, targeted therapy is becoming a hot topic due to its high efficiency and low toxicity. Drug effects of targeted tumor drugs are closely related to pharmacokinetics, so it is important to understand their distribution and metabolism in vivo. Methods: A systematic review of the literature on the metabolism and distribution of targeted drugs over the past 20 years was conducted, and the pharmacokinetic parameters of approved targeted drugs were summarized in combination with the FDA's drug instructions. Targeting drugs are divided into two categories: small molecule inhibitors and monoclonal antibodies. Novel targeting drugs and their mechanisms of action, which have been developed in recent years, are summarized. The distribution and metabolic processes of each drug in the human body are reviewed. Results: In this review, we found that the distribution and metabolism of small molecule kinase inhibitors (TKI) and monoclonal antibodies (mAb) showed different characteristics based on the differences of action mechanism and molecular characteristics. TKI absorbed rapidly (Tmax ≈ 1-4 h) and distributed in large amounts (Vd > 100 L). It was mainly oxidized and reduced by cytochrome P450 CYP3A4. However, due to the large molecular diameter, mAb was distributed to tissues slowly, and the volume of distribution was usually very low (Vd < 10 L). It was mainly hydrolyzed and metabolized into peptides and amino acids by protease hydrolysis. In addition, some of the latest drugs are still in clinical trials, and the in vivo process still needs further study. Conclusion: According to the summary of the research progress of the existing targeting drugs, it is found that they have high specificity, but there are still deficiencies in drug resistance and safety. Therefore, the development of safer and more effective targeted drugs is the future research direction. Meanwhile, this study also provides a theoretical basis for clinical accurate drug delivery.

scholarly journals Three-dimensional distribution of CT attenuation in the lumbar spine pedicle wall

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomoyo Y. Irie ◽  
Tohru Irie ◽  
Alejandro A. Espinoza Orías ◽  
Kazuyuki Segami ◽  
Norimasa Iwasaki ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Age Groups ◽  
Three Dimensional ◽  
Hounsfield Unit ◽  
Lateral Wall ◽  
Ct Attenuation ◽  
Dimensional Distribution ◽  
The Mean ◽  
Pedicle Wall

AbstractThis study investigated in vivo the three-dimensional distribution of CT attenuation in the lumbar spine pedicle wall measured in Hounsfield Unit (HU). Seventy-five volunteers underwent clinical lumbar spine CT scans. Data was analyzed with custom-written software to determine the regional variation in pedicle wall attenuation values. A cylindrical coordinate system oriented along the pedicle’s long axis was used to calculate the pedicular wall attenuation distribution three-dimensionally and the highest attenuation value was identified. The pedicular cross-section was divided into four quadrants: lateral, medial, cranial, and caudal. The mean HU value for each quadrant was calculated for all lumbar spine levels (L1–5). The pedicle wall attenuation was analyzed by gender, age, spinal levels and anatomical quadrant. The mean HU values of the pedicle wall at L1 and L5 were significantly lower than the values between L2–4 in both genders and in both age groups. Furthermore, the medial quadrant showed higher HU values than the lateral quadrant at all levels and the caudal quadrant showed higher HU values at L1–3 and lower HU values at L4–5 than the cranial quadrant. These findings may explain why there is a higher incidence of pedicle screw breach in the pedicle lateral wall.

scholarly journals Identification of Resistance Determinants for a Promising Antileishmanial Oxaborole Series

2021 ◽  
Vol 9 (7) ◽  
pp. 1408
Author(s):  
Magali Van den Kerkhof ◽  
Philippe Leprohon ◽  
Dorien Mabille ◽  
Sarah Hendrickx ◽  
Lindsay B. Tulloch ◽  
...  
Keyword(s):  
Drug Exposure ◽  
In Vitro Selection ◽  
Selection Procedure ◽  
Cosmid Library ◽  
Neglected Diseases ◽  
Chromosome 2 ◽  
Resistance Determinants ◽  
A Genome

Current treatment options for visceral leishmaniasis have several drawbacks, and clinicians are confronted with an increasing number of treatment failures. To overcome this, the Drugs for Neglected Diseases initiative (DNDi) has invested in the development of novel antileishmanial leads, including a very promising class of oxaboroles. The mode of action/resistance of this series to Leishmania is still unknown and may be important for its further development and implementation. Repeated in vivo drug exposure and an in vitro selection procedure on both extracellular promastigote and intracellular amastigote stages were both unable to select for resistance. The use of specific inhibitors for ABC-transporters could not demonstrate the putative involvement of efflux pumps. Selection experiments and inhibitor studies, therefore, suggest that resistance to oxaboroles may not emerge readily in the field. The selection of a genome-wide cosmid library coupled to next-generation sequencing (Cos-seq) was used to identify resistance determinants and putative targets. This resulted in the identification of a highly enriched cosmid, harboring genes of chromosome 2 that confer a subtly increased resistance to the oxaboroles tested. Moderately enriched cosmids encompassing a region of chromosome 34 contained the cleavage and polyadenylation specificity factor (cpsf) gene, encoding the molecular target of several related benzoxaboroles in other organisms.

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