scholarly journals Evaluation of the ultrastructural and in vitro flow properties of the PreserFlo® microShunt

2022 ◽  
Vol 100 (S267) ◽  
Author(s):  
Marta Ibarz Barberá ◽  
Jean Bragard ◽  
laura Morales Fernández ◽  
Pedro Tañá Rivero ◽  
Rosario Gomez de Liaño ◽  
...  
Keyword(s):  
Flow Properties

scholarly journals BIODEGRADABLE POLYMER: A NOVEL PHARMACEUTICAL CARRIER FOR SUSTAINED RELEASE OF METRONIDAZOLE

2017 ◽  
Vol 10 (10) ◽  
pp. 136
Author(s):  
Gayathri Hariharan ◽  
Priyanka Sinha
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Sustained Release ◽  
Biodegradable Polymer ◽  
Drug Loading ◽  
Cross Linking ◽  
Loading Capacity ◽  
Flow Properties ◽  
Chitosan Microspheres

Objective: To optimize and evaluate the formulation of metronidazole (MT)-loaded chitosan microspheres and to investigate the efficiency of biodegradable polymer in developing sustained release formulation of MT to prolong the action of drug.Methods: MT microspheres were prepared using emulsion cross-linking method. Polymer-drug compatibility study was done using Fourier transform infrared. Physical characteristics were evaluated by particle size,SEM, flow properties etc. In vitro studies for evaluating drug release for MT-loaded chitosan microspheres were done by dissolution study.Results: Particle size of the formulated microspheres was found to be within the range of 110-130 μm. Flow properties of F1-F7 such as angle of repose, bulk density, and tapped density were found to be within limits. Drug entrapment efficiency was found to be better for all the formulations within the range of 74.82-84.32% w/w. Drug loading capacity was found to be in the range of 56-83.2% w/v. In vitro drug release was found to be in the range of 81.32-96.23% w/v.Conclusion: In spite of all the above results, we conclude that F5 formulation was optimized depending on the data obtained from the drug loading capacity and percentage drug release studies. F5 formulation is formulated with drug-polymer ratio 1:2 with 1% of di octyl sodium sulfo succinate and 8 ml of glutaraldehyde as a cross-linking agent.

NOVEL PHARMACEUTICAL COCRYSTAL OF TELMISARTAN AND HYDROCHLOROTHIAZIDE

2020 ◽  
pp. 104-112
Author(s):  
ALPANA KULKARNI ◽  
SWAPNIL SHETE ◽  
VISHAL HOL ◽  
RITESH BACHHAV
Keyword(s):  
Maximum Yield ◽  
In Vitro Release ◽  
Active Pharmaceutical Ingredient ◽  
Flow Properties ◽  
Acidic Group ◽  
X Ray ◽  
Poorly Soluble ◽  
Pharmaceutical Cocrystal ◽  
Vitro Release

Objective: Telmisartan (TEL), commonly used antihypertensive, is poorly soluble in water and has limited and variable bioavailability. Commercially, TEL is available as a single drug and in combination with hydrochlorothiazide (HYZ). Researchers have developed cocrystals of TEL with coformers, namely, oxalic acid, glutaric acid, and saccharin. An attempt was made to prepare the cocrystals of TEL with HYZ, an active pharmaceutical ingredient (API) itself so that both the APIs are available in a single tablet. The present study was aimed at enhancement in solubility of TEL by formation of its cocrystals. Methods: The cocrystals of TEL with HYZ, in different stoichiometric ratios (1:0.5, 1:1, and 1:2), were prepared by solvent coevaporation and liquid-assisted grinding methods. The cocrystals, consisting of TEL:HYZ (in 1:0.5 ratio and 1:1 ratio), depicted maximum yield, drug content, saturation solubility, and flow properties. These cocrystals were characterized by X-ray analysis, infrared spectroscopy, and thermal analysis. Results: The crystal structure of TEL-HYX revealed that it was a cocrystal, since no proton was transferred between the TEL and HYZ molecules. It was predicted that two molecules are associated through a hydrogen bond between an acidic group of TEL and sulfonamido group of HYZ. The cocrystallization improved the solubility of TEL 7 times. In vitro release rate of tablets of cocrystals was higher than that of marketed TEL tablets. HYZ has a potential to form the cocrystals of TEL. Conclusion: The objective of improvement in the solubility of TEL was successfully achieved by the formation of cocrystals of TEL: HYZ.

Mucus clearance: in vivo canine tracheal vs. in vitro bullfrog palate studies

1977 ◽  
Vol 42 (5) ◽  
pp. 761-766 ◽  
Author(s):  
A. Giordano ◽  
C. K. Shih ◽  
D. S. Holsclaw ◽  
M. A. Khan ◽  
M. Litt
Keyword(s):  
Cystic Fibrosis ◽  
Mucociliary Clearance ◽  
Objective Method ◽  
Flow Properties ◽  
Therapeutic Modalities ◽  
Mucus Clearance ◽  
Clearance Studies ◽  
Frog Palate

Tracheal mucociliary clearance was studied by a radioisotope technique in pentothal-anesthetized beagles in the control, atropinized, or dehydrated state. Mucus collected from a tracheal pouch in each dog was used for in vitro bullfrog (Rana cantesbiana) palate clearance studies and compared to the in vivo clearance rates. In all three experimental states, there was a significant correlation between in vivo and in vitro rates, suggesting that tracheal pouch mucus is a good model for investigating the mucociliary flow properties of intact airway mucus. When compared to matched controls, atropine appeared to cause a slowing of the in vivo clearance rate but not of the in vitro rate. Dehydration had no effect on either. The appropriateness of the frog palate method in the study of human respiratory disease (e.g., chronic bronchitis, cystic fibrosis) as well as its potential as an objective method of assessing the effects of various therapeutic modalities in these diseases is discussed.

Compliance Effect on the Flow Condition in Vascular In Vitro Experiments

2018 ◽  
Author(s):  
Masami Matsuura ◽  
Simon Tupin ◽  
Makoto Ohta
Keyword(s):  
Flow Rate ◽  
Time Lag ◽  
Flow Patterns ◽  
Poly Vinyl Alcohol ◽  
Circulation System ◽  
Straight Tube ◽  
Flow Conditions ◽  
Flow Properties ◽  
Clinician Training

Endovascular treatment has become the standard for intracranial aneurysm management. In vitro systems including an artery model are required for devices evaluation and clinician training. Although silicone is usually use for such model, its compliance is known to be lower than blood vessels. The purpose of this study was to analyze the influence of model material compliance on flow properties. Silicone and 12 [wt%] poly (vinyl alcohol) hydrogel (PVA-H) were used to create two box-shaped models of significantly different compliance. The inner lumen geometry was a 4 [mm] diameter straight tube (parent vessel) and a 10 [mm] diameter sphere representing the aneurysm. A blood-mimicking fluid made of a mixture of glycerin, water and sodium iodide was used to reproduce the viscosity and density of blood and fit models refractive index. The circulation system consisted of a pulsatile blood pump and resistance valve. A flow rate of 250±50 [ml/min] and pressure from 75 to 115 [mmHg] were set inside the model. Pressure and flow rate sensors were used to monitor flow conditions before and after the model. Particle image velocimetry (PIV) was performed to record the difference of flow patterns inside the aneurysm of both model using a Nd:YAG solid laser system and fluorescent particles. Results revealed a significant change of flow conditions due to model compliance. Attenuation of the flow rate pulse was recorded between the inlet and the outlet of the both model. This attenuation was 51% for PVA-H model. Moreover, a time lag between outlet pressure and outlet flow rate curves was recorded in both model. This time lag was longer with the PVA-H model, as this model exhibit a greater compliance. PIV experiments revealed significant changes of flow patterns and velocity inside the aneurysm. Because of its high compliance, PVA-H model walls moved under the pulsatile conditions. A change of flow direction and decrease of its velocity were observed near the proximal wall of the aneurysm, compared to the silicone model. Such differences might modify the stress on the wall of the aneurysm. To conclude, our experiments revealed that compliance has significant impacts on flow properties and should be taken into account for in vitro vascular model manufacturing.

Beta-Cyclodextrin and Maltodextrin Based Solid Dispersion of Meloxicam to Enhance the Solubility of Meloxicam; Formulation and In-vitro Evaluation

2019 ◽  
Vol 41 (1) ◽  
pp. 133-133
Author(s):  
Muhammad Zaman Muhammad Zaman ◽  
Muhammad Hanif Muhammad Hanif ◽  
Syed Saeed Ul Hassan Syed Saeed Ul Hassan ◽  
Javed Iqbal and Muhammad Ahmad Shehzad Javed Iqbal and Muhammad Ahmad Shehzad
Keyword(s):  
Solid Dispersion ◽  
X Ray Diffraction ◽  
Flow Properties ◽  
Scanning Calorimetry ◽  
In Vitro Drug Release ◽  
X Ray ◽  
Beta Cyclodextrin ◽  
Release Studies ◽  
Pure Drug

The purpose of the current study was to enhance the solubility of the meloxicam (MLX) by preparing complex with β-Cyclodextrin (CD) and maltodextrin (MD). Dextrins have the ability to capture the drug inside their cavities without forming any chemical bonding. Three (3) formulations, each of solid dispersion (SD) and physical mixture (PM) were prepared by using different drug to polymer ratios (1:4, 1:6 and 1:8) followed by evaluation for micromeritic properties, drug contents, and in vitro drug release studies, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and x-ray diffraction (XRD) studies. Chemical compatibility of the ingredients was evaluated by using Fourier transform infrared spectroscopy (FTIR). Results of conducted studies exposed excellent flow properties of SDs as well as prepared PMs, with reasonable amount of loaded drug, i.e. andgt;90%. SEM showed a bit irregular surface while XRD suggested crystalline behavior of pure drug, which was masked after its conversion into SDs and PMs based on dextrins. Solubility of the MLX was increased significantly form its initial extent of solubility i.e. 12.5 and#181;g/ml in pure form to 786.72 and#181;g/ml in the form of SD (pandlt;0.05), advocating suitability of materials and methods for solubility enhancement of MLX.

scholarly journals Preparation and characterization of Gliclazide incorporated Cellulosic Microspheres: studies on drug release, compatibility and micromeritics

2015 ◽  
Vol 13 (2) ◽  
pp. 149-166 ◽  
Author(s):  
Navid Jubaer Ayon ◽  
Ikramul Hasan ◽  
Md Shfiqul Islam ◽  
Md Selim Reza
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Surface Morphology ◽  
Sustained Release ◽  
Release Rate ◽  
Drug Loading ◽  
Angle Of Repose ◽  
Flow Properties ◽  
Dissolution Apparatus

Polymeric microspheres of gliclazide were prepared to provide sustained release delivery of gliclazide to aid in continuous therapy with high margin of safety. Gliclazide was microencapsulated with different polymers namely HPMC K100LV, Ethocel (20 cps) and HPMC K100M by emulsion solvent evaporation technique using acetone as internal phase and liquid paraffin as external phase. Seventeen formulations were prepared using different drug loading and polymeric ratio of which nine formulations were prepared by a 32 full factorial design. Each formulation was evaluated for flow properties, particle size, surface morphology, drug entrapment efficiency, drug release and compatibility. Yield (%) for every batch of microspheres was measured. Flow properties of the microspheres were examined by determining bulk density, tapped density, Carr’s compressibility index, Hausner ratio and angle of repose. Particle size distribution was examined by sieving and particle size analyzer. Surface morphology was determined by scanning electron microscopy (SEM). In-vitro drug release was studied in a paddle type dissolution apparatus (USP Type II Dissolution Apparatus) for a period of 8 hours at 37°C using phosphate buffer ( pH 7.4). FTIR and DSC studies established compatibility of the drug with the polymers. Microspheres prepared with Ethocel (20 cps) and HPMC K100M were free flowing than those prepared only with HPMC K100LV. Entrapment efficiencies were within 75.88-99.69%. Microspheres prepared with Ethocel (20 cps) and HPMC K100M showed more sustained release when compared to microspheres prepared with HPMC K100LV only. Increase in drug loading resulted in increased drug release for the microspheres. Kinetic modeling of in vitro dissolution profiles revealed the drug release mechanism ranging from diffusion controlled to anomalous type. Ethocel and HPMC K100M in a ratio of 1:3 exhibited better sustained release properties than 1:1 and 3:1 ratios. The release rate of gliclazide from microspheres prepared with Ethocel (20 cps) and HPMC K100M was less than the release rate of gliclazide from microspheres prepared with HPMC K100LV, demonstrating Ethocel and HPMC K100M as suitable polymeric blend for preparing the controlled release formulation for gliclazide whereas, HPMC K100LV was found not suitable candidate when used alone as a polymer. DOI: http://dx.doi.org/10.3329/dujps.v13i2.21893 Dhaka Univ. J. Pharm. Sci. 13(2): 149-166, 2014 (December)

scholarly journals In Vitro Measurements of the Effects of Anticoagulants on the Flow Properties of Blood: The Relationship of these Effects to Red Cell Shrinkage

Blood ◽  
1968 ◽  
Vol 31 (2) ◽  
pp. 234-241 ◽  
Author(s):  
WILLIAM I. ROSENBLUM
Keyword(s):  
Cell Size ◽  
Blood Viscosity ◽  
Plasma Viscosity ◽  
Red Cell ◽  
Flow Properties ◽  
Cell Shrinkage ◽  
In Vitro Measurements ◽  
Relationship Of ◽  
The Relationship

Abstract Citrate and oxalate increased the viscosity of blood as measured in a capillary viscosimeter. The elevated viscosity was accompanied by erytrhocyte shrinkage, manifest by the decreased hematocrit of blood anticoagulated with either of these agents. Plasma viscosity was not affected. EDTA, which does not alter cell size or shape, also failed to alter blood viscosity, while citrate no longer affected viscosity, if utilized in ACD solution, a milieu which prevents cell shrinkage. When erythrocytes were suspended in hypertonic NaCl, "blood" viscosity was also elevated in comparison to that of suspensions in lower concentrations of NaCl. The data indicate that blood viscosity will be elevated by anticoagulants which are permitted to shrink erythrocytes.

scholarly journals Encapsulation of Anthocyanins from Cornelian Cherry Fruits Using Heated or Non-Heated Soy Proteins

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1342
Author(s):  
Loredana Dumitrașcu ◽  
Nicoleta Stănciuc ◽  
Iuliana Aprodu
Keyword(s):  
Encapsulation Efficiency ◽  
Freeze Drying ◽  
Morphological Analysis ◽  
Soy Proteins ◽  
Effect Of Temperature ◽  
Low Density ◽  
Flow Properties ◽  
Cornelian Cherry ◽  
Heat Treated

In the current study, the effect of temperature on the potential of soy proteins to ensure the encapsulation and gastric stability of bioactives, such as anthocyanins from cornelian cherry fruits, was investigated. The powders obtained after freeze-drying were analyzed in relation to flow properties, encapsulation retention and efficiency, stability in simulated gastrointestinal medium, color, and morphology. Preheating the soy proteins generated a powder with low density. Powders obtained with native soy proteins allowed the highest encapsulation efficiency and the lowest was obtained when using preheated soy proteins. The heat treatment of the mixture of soy proteins and cornelian cherry fruits prior to encapsulation generated powders with the highest lightness and the lowest intensity of red shades among all samples. The in vitro experiments revealed that the highest protection in simulated gastric environment was provided when protein was heat treated either alone or in combination with bioactives to be encapsulated. The morphological analysis highlighted that powders consisted of large and rigid structures.

Formulation and evaluation of sustained release saxagliptin microspheres by ionotropic gelation method

2017 ◽  
Vol 6 (03) ◽  
pp. 5328
Author(s):  
Madhuri Latha Thadanki*
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Sodium Alginate ◽  
In Vitro Study ◽  
Entrapment Efficiency ◽  
Release Kinetic ◽  
Flow Properties ◽  
Ionotropic Gelation ◽  
Drug Entrapment Efficiency

The objective of the current investigation is to reduce dosing frequency and improve patient compliance by designing and systematically evaluating sustained release microspheres of an antidiabetic agent, saxagliptin. Saxagliptin microspheres were formulated using sodium alginate as the controlled release polymer by ionotropic gelation technique. The polymer sodium alginate alone and along with different coating polymers like pectin, ethyl cellulose was used in different ratios (1:1,1:1.5, 1:2 ) to formulate batches F1 to F9. The resulting microspheres were evaluated for particle size, densities, flow properties, morphology, recovery yield, drug content, drug entrapment efficiency and in vitro drug release behavior. The formulated microspheres were discrete, spherical with relatively smooth surface, and with good flow properties. The drug entrapment efficiency obtained in the range 70.4% to 95.2%.Among different formulations, the fabricated microspheres of batch F3 had shown the optimum percent drug encapsulation of microspheres and the sustained release of the saxagliptin for about 9 h. In vitro study showed that drug release slowly increases as the pH of the medium is increased. Release pattern of saxagliptin from microspheres of batch F3 followed Higuchi model and zero-order release kinetic model. The value of ‘n’ was found to be 0.867. The data obtained thus suggest that a microparticulate system can be successfully designed for sustained delivery of saxagliptin and to improve dosage form characteristics for easy formulation.

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