scholarly journals Preliminary Investigation of the Dissolution Behavior, Cytocompatibility, Effects of Fibrinogen Conformation and Platelet Adhesion for Radiopaque Embolic Particles

2021 ◽  
Author(s):  
Sharon Kehoe ◽  
Marie-Laurence Tremblay ◽  
Aisling Coughlan ◽  
Mark R. Towler ◽  
Jan K. Rainey ◽  
...  

Experimental embolic particles based on a novel zinc-silicate glass system have been biologically evaluated for potential consideration in transcatheter arterial embolization procedures. In addition to controlling the cytotoxicity and haemocompatibility for such embolic particles, its glass structure may mediate specific responses via dissolution in the physiological environment. In a 120 h in-vitro dissolution study, ion release levels for silicon (Si4+), sodium (Na+), calcium (Ca2+), zinc (Zn2+), titanium (Ti4+), lanthanum (La3+), strontium (Sr2+), and magnesium (Mg2+), were found to range from 0.04 to 5.41 ppm, 0.27–2.28 ppm, 2.32–8.47 ppm, 0.16–0.20 ppm, 0.12–2.15 ppm, 0.16–0.49 ppm and 0.01–0.12 ppm, respectively for the series of glass compositions evaluated. Initial release of Zn2+ (1.93–10.40 ppm) was only evident after 120 h. All compositions showed levels of cell viabilities ranging from 61.31 ± 4.33% to 153.7 ± 1.25% at 25%–100% serial extract dilutions. The conformational state of fibrinogen, known to induce thrombi, indicated that no changes were induced with respect of the materials dissolution by-products. Furthermore, the best-in-class experimental composition showed equivalency to contour PVA in terms of inducing platelet adhesion. The data generated here provides requisite evidence to continue to in-vivo pre-clinical evaluation using the best-in-class experimental composition evaluated.

2021 ◽  
Author(s):  
Sharon Kehoe ◽  
Marie-Laurence Tremblay ◽  
Aisling Coughlan ◽  
Mark R. Towler ◽  
Jan K. Rainey ◽  
...  

Experimental embolic particles based on a novel zinc-silicate glass system have been biologically evaluated for potential consideration in transcatheter arterial embolization procedures. In addition to controlling the cytotoxicity and haemocompatibility for such embolic particles, its glass structure may mediate specific responses via dissolution in the physiological environment. In a 120 h in-vitro dissolution study, ion release levels for silicon (Si4+), sodium (Na+), calcium (Ca2+), zinc (Zn2+), titanium (Ti4+), lanthanum (La3+), strontium (Sr2+), and magnesium (Mg2+), were found to range from 0.04 to 5.41 ppm, 0.27–2.28 ppm, 2.32–8.47 ppm, 0.16–0.20 ppm, 0.12–2.15 ppm, 0.16–0.49 ppm and 0.01–0.12 ppm, respectively for the series of glass compositions evaluated. Initial release of Zn2+ (1.93–10.40 ppm) was only evident after 120 h. All compositions showed levels of cell viabilities ranging from 61.31 ± 4.33% to 153.7 ± 1.25% at 25%–100% serial extract dilutions. The conformational state of fibrinogen, known to induce thrombi, indicated that no changes were induced with respect of the materials dissolution by-products. Furthermore, the best-in-class experimental composition showed equivalency to contour PVA in terms of inducing platelet adhesion. The data generated here provides requisite evidence to continue to in-vivo pre-clinical evaluation using the best-in-class experimental composition evaluated.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1210
Author(s):  
Xieguo Yan ◽  
Shiqiang Wang ◽  
Kaoxiang Sun

Schizophrenia, a psychiatric disorder, requires long-term treatment; however, large fluctuations in blood drug concentration increase the risk of adverse reactions. We prepared a long-term risperidone (RIS) implantation system that can stabilize RIS release and established in-vitro and in-vivo evaluation systems. Cumulative release, drug loading, and entrapment efficiency were used as evaluation indicators to evaluate the effects of different pore formers, polymer ratios, porogen concentrations, and oil–water ratios on a RIS implant (RIS-IM). We also built a mathematical model to identify the optimized formulation by stepwise regression. We also assessed the crystalline changes, residual solvents, solubility and stability after sterilization, in-vivo polymer degradation, pharmacokinetics, and tissue inflammation in the case of the optimized formulation. The surface of the optimized RIS microspheres was small and hollow with 134.4 ± 3.5 µm particle size, 1.60 SPAN, 46.7% ± 2.3% implant drug loading, and 93.4% entrapment efficiency. The in-vitro dissolution behavior of RIS-IM had zero-order kinetics and stable blood concentration; no lag time was released for over three months. Furthermore, the RIS-IM was not only non-irritating to tissues but also had good biocompatibility and product stability. Long-acting RIS-IMs with microspheres and film coatings can provide a new avenue for treating schizophrenia.


2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Feng Wang ◽  
Timothy J. Barnes ◽  
Clive A. Prestidge

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


2007 ◽  
Vol 30 (11) ◽  
pp. 2221-2225 ◽  
Author(s):  
Hidekatsu Nishimura ◽  
Chiaki Hayashi ◽  
Tetsuya Aiba ◽  
Ichiro Okamoto ◽  
Yuji Miyamoto ◽  
...  

2007 ◽  
Vol 361-363 ◽  
pp. 7-10 ◽  
Author(s):  
Saartje Impens ◽  
Roosmarijn Schelstraete ◽  
Steven Mullens ◽  
Ivo Thijs ◽  
Jan Luyten ◽  
...  

The degradation rate of custom made calcium phosphate scaffolds, designed for bone tissue engineering applications, influences the healing process of critical size bone defects. An optimal degradation rate exists at which the neo-formed bone replaces the CaP (calcium phosphate) scaffold [1]. Consequently investigating the complex degradation behavior (dissolution, reprecipitation, osteoclast activity) of custom made CaP structures gains interest. In this work different in vitro dissolution experiments were performed to study the degradation behavior of 4 by composition different calcium phosphates. Ideally these experiments should have a predictive power regarding the in vivo degradation behavior. In vitro dissolution tests still lack standardization. Therefore this study focuses on the influence of two dissolution constraints: (i) the material’s macrostructure (porous - dense), (ii) the regenerated fluid flow (bath shaking - perfusion). From 4 different CaP compositions porous structures and as a reference dense disks were produced, using the same starting powder and heat treatment. To compare the different dissolution tests, all data was normalized to the CaP surface area. Results show that besides the structural appearances of the CaP structures, also the design of the dissolution test influences the in vitro dissolution behavior. Moreover there is a need to take the morphology of the dissolved material into account. The CaP perfusion tests show dissolution dynamics that resemble the in vivo reality more closely than the shaking bath experiments.


1997 ◽  
Vol 77 (05) ◽  
pp. 0975-0980 ◽  
Author(s):  
Angel Gálvez ◽  
Goretti Gómez-Ortiz ◽  
Maribel Díaz-Ricart ◽  
Ginés Escolar ◽  
Rogelio González-Sarmiento ◽  
...  

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.


2018 ◽  
Vol 4 (4) ◽  
pp. 523-531
Author(s):  
Hina Mumtaz ◽  
Muhammad Asim Farooq ◽  
Zainab Batool ◽  
Anam Ahsan ◽  
Ashikujaman Syed

The main purpose of development pharmaceutical dosage form is to find out the in vivo and in vitro behavior of dosage form. This challenge is overcome by implementation of in-vivo and in-vitro correlation. Application of this technique is economical and time saving in dosage form development. It shortens the period of development dosage form as well as improves product quality. IVIVC reduce the experimental study on human because IVIVC involves the in vivo relevant media utilization in vitro specifications. The key goal of IVIVC is to serve as alternate for in vivo bioavailability studies and serve as justification for bio waivers. IVIVC follows the specifications and relevant quality control parameters that lead to improvement in pharmaceutical dosage form development in short period of time. Recently in-vivo in-vitro correlation (IVIVC) has found application to predict the pharmacokinetic behaviour of pharmaceutical preparations. It has emerged as a reliable tool to find the mode of absorption of several dosage forms. It is used to correlate the in-vitro dissolution with in vivo pharmacokinetic profile. IVIVC made use to predict the bioavailability of the drug of particular dosage form. IVIVC is satisfactory for the therapeutic release profile specifications of the formulation. IVIVC model has capability to predict plasma drug concentration from in vitro dissolution media.


Author(s):  
Narendar Dudhipala ◽  
Arjun Narala ◽  
Dinesh Suram ◽  
Karthik Yadav Janga

The objective of this present study is to develop a semisolid dispersion (SSD) of zaleplon with the aid of self-emulsifying lipid based amphiphilic carriers (TPGS E or Gelucire 44/14) addressing the poor solubility of this drug. A linear relationship between the solubility of drug with respect to increase in the concentration of lipid surfactant in aqueous medium resulting in AL type phase diagram was observed from phase solubility studies. Fusion method was employed to obtain semisolid dispersions (SSD) of zaleplon which showed high content uniformity of drug. The absence of chemical interactions between the pure drug, excipients and formulations were conferred by Fourier transmission infrared spectroscopic examinations. The photographic images from polarized optical microscopic studies revealed the change in crystalline form of drug to amorphous or molecular state. The superior dissolution parameters of zaleplon from SSD over pure crystalline drug interpreted from in vitro dissolution studies envisage the ability of these lipid surfactants as solubility enhancers. Further, the caliber of TPGS E or Gelucire 44/14 in encouraging the GI absorption of drug was evident with the higher human effective permeability coefficient and fraction oral dose of drug absorbed from SSD in situ intestinal permeation study. In conclusion, in vivo studies in Wister rats demonstrated an improvement in the oral bioavailability of zaleplon from SSD over control pure drug suspension suggesting the competence of Gelucire 44/14 and TPGS E as conscientious carriers to augment the dissolution rate limited bioavailability of this active


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