Search results for "solubility"

Influence of polymer molecular weight on in vitro dissolution behavior and in vivo performance of celecoxib:PVP amorphous solid dispersions

2016

In this study, the influence of the molecular weight of polyvinylpyrrolidone (PVP) on the non-sink in vitro dissolution and in vivo performance of celecoxib (CCX):PVP amorphous solid dispersions were investigated. The dissolution rate of CCX from the amorphous solid dispersions increased with decreasing PVP molecular weight and crystallization inhibition was increased with increasing molecular weight of PVP, but reached a maximum for PVP K30. This suggested that the crystallization inhibition was not proportional with molecular weight of the polymer, but rather there was an optimal molecular weight where the crystallization inhibition was strongest. Consistent with the findings from the non…

Effect of polymer type and drug dose on the in vitro and in vivo behavior of amorphous solid dispersions.

2016

This study investigated the non-sink in vitro dissolution behavior and in vivo performance in rats of celecoxib (CCX) amorphous solid dispersions with polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC) at different drug doses. Both in vitro and in vivo, the amorphous solid dispersions with the hydrophilic polymers PVP and HPMC led to higher areas under both, the in vitro dissolution and the plasma concentration-time curves (AUC) compared to crystalline and amorphous CCX for all doses. In contrast, the amorphous solid dispersion with the hydrophobic polymer PVA showed a lower AUC both in vitro and in vivo than crystalline CCX. For crystalline CCX and…

Use of nonlinear mixed effect modeling for the intestinal absorption data: application to ritonavir in the rat.

2005

The aim of this study is to investigate in situ the mechanisms involved in the gastrointestinal absorption of ritonavir in the rat, as an animal model for preclinical studies of anti-HIV agents in vivo. Four ritonavir solutions (40, 27, 13 and 7 microM) in the presence of 1% dimethylsulfoxide (DMSO) were perfused in the small intestine of anaesthetised rats. Effects of DMSO on the intestinal permeability were investigated using solutions containing antipyrine 1.33 mM and ritonavir 7 microM with and without 1% of DMSO. Antipyrine and ritonavir transport was not modified in the presence of 1% of DMSO. The population pharmacokinetic parameters of the ritonavir intestinal transport were obtaine…

Soluble CD40L and Cardiovascular Risk in Asymptomatic Low-Grade Carotid Stenosis

2005

Background and Purpose— We investigated whether soluble CD40L (sCD40L) may predict the risk of cardiovascular (CV) events in patients with asymptomatic carotid plaques. Methods— Forty-two patients with asymptomatic low-grade carotid stenosis (ALCS) and 21 controls without any carotid stenosis were enrolled. All subjects had at least a major cardiovascular risk factor (CRF). Plasma levels of C-reactive protein (CRP), IL-6, and sCD40L were measured. Subjects were reviewed every 12 months (median follow-up, 8 years). Results— ALCS patients had higher ( P <0.0001) CRP, IL-6, and sCD40L than controls. Fourteen patients experienced a CV event. Cox regression analysis showed that only high sCD…

Effect of surfactants on Albendazole absorption

1991

Circulating TNF-alpha and its soluble receptors during experimental acute pancreatitis.

2004

Clinical and experimental studies have shown increased concentrations of TNF-α and its soluble receptors in serum of patients with acute pancreatitis. In this work, we have investigated the time-course of TNF-α and its soluble receptors during taurocholate-induced acute pancreatitis. In addition, since TNF-α itself could mediate the shedding of its receptors, we have assessed the effect of inhibiting TNF-α production on the release of soluble TNF-α receptors in experimental acute pancreatitis. Our results indicate that soluble receptors are released in the early stages of the disease and this increase is concomitant with the release of TNF-α, which is mainly bound to specific proteins. The …

Left ventricular diastolic function and cardiometabolic factors in obese normotensive children

2014

Abstract Background and aim Left ventricular (LV) hypertrophy and diastolic function have been found to be associated with obesity and hypertension in adults. However, there are scarce data about the association of obesity itself to cardiac alteration in children. The aim of this study was to detect early changes in LV structure and function in obese children and whether they are associated with the biomarkers of metabolic risk and endothelial activation. Methods and results A total of 130 children aged 7–16 years (88 obese and 42 normal-weight children) were studied. All children had normal resting blood pressure. Two-dimensional ultrasound with M-mode imaging was performed to assess the L…

Connective tissue of “fast” and “slow” skeletal muscle in rats…effects of endurance training

1980

The connective tissue of two skeletal muscles having different contractile properties was investigated in trained and untrained rats. The animals to be trained were put to run on a treadmill 5 days a week for 4 weeks. The "slow" m. soleus (MS) showed higher malate dehydrogenase activity but lower lactate dehydrogenase activity compared to the "fast" m. rectus femoris (MRF). When whole muscles were taken into account, the concentrations of both hydroxyproline and hexosamines were higher for MS compared to MRF. In the middle section of MS there were more hexosamines than in that of MRF, but no similar difference existed in hydroxyproline. The histochemical staining of collagen, however, sugge…

Enhanced serum levels of soluble HLA class I molecules are induced by treatment with recombinant interferon-gamma (IFN-γ)

1991

SUMMARY In order to investigate serum levels of soluble HLA class I antigens after single injection of various doses of recombinant IFN-γ (rIFN-γ) and to correlate the changes observed to beta-2-microglobulin serum levels, we studied five patients with metastasizing renal cell carcinoma. Each patient received three treatment cycles of 10, 100 and 500 μg rIFN-γ three times at weekly intervals. The treatment cycles were separated by a therapy-free interval of 2 weeks. The order of dose levels was randomly assigned to each patient. Serum levels of soluble HLA class I proteins were measured by an ELISA in samples drawn immediately before and 4, 24, 48, 72 and 168 h after each administration of …

Aqueous Solubility Diagrams for Cementitious Waste Stabilization Systems. 4. A Carbonation Model for Zn-Doped Calcium Silicate Hydrate by Gibbs Energ…

2002

A thermodynamic Gibbs energy minimization (GEM) solid solution-aqueous solution (SSAS) equilibrium model was used to determine the solubility of Zn from calcium silicate hydrate (CSH) phases doped with 0, 0.1, 1, 5, and 10% Zn at a unity (Ca+Zn)/Si molar ratio. Both the stoichiometry and standard molar Gibbs energy (G(o)298) of the Zn-bearing end-member in the ideal ternary Zn-bearing calcium silicate hydrate (CZSH) solid solution were determined by a "dual-thermodynamic" (GEM-DT) estimation technique. The SSAS model reproduces a complex sequence of reactions suggested to occur in a long-term weathering scenario of cementitious waste forms at subsurface repository conditions. The GEM model …