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Food Research International (Ottawa,... Nov 2022The polymeric suspension of chitosan (Ch) has been an effective media for the extraction of total phenolic compounds (TPC) from the acerola by-product. It facilitates...
The polymeric suspension of chitosan (Ch) has been an effective media for the extraction of total phenolic compounds (TPC) from the acerola by-product. It facilitates the subsequent production of nanoparticles loaded with the phenolics (Np-TPC) by ionic gelation. However, neither the effects of Ch concentration on encapsulation efficiency (EE%) of TPC nor which compounds are extracted in its media are known, being it the first objective of this study. The second objective was to analyze the stability of the Np-TPC under accelerated conditions and its release profile at pHs 3.0 and 7.0. The results showed that Ch does not affect the extraction of TPC. However, the EE increased from 35.0 to 48.1 % with the increase of Ch concentration (0.4 to 1.0 %). LC/ESI-QTOF MS analysis showed that phenolic acids and flavonoids are extracted in 0.8 % Ch medium. After encapsulation, microscopy images revealed particle sizes ranging between 110 and 150 nm. Additionally, the presence of phenolics did not change the stability of the particles under accelerated conditions and the actives were fully released into the released medium for 10 h. The Np-TPC suspension appears to be useful for the production of edible antioxidant coatings to preserve fruits/vegetables, with potential application as carrier of other food ingredients.
Topics: Antioxidants; Ascorbic Acid; Chitosan; Flavonoids; Food Ingredients; Malpighiaceae; Phenols; Rutin; Suspensions
PubMed: 36192901
DOI: 10.1016/j.foodres.2022.111855 -
Scientific Reports May 2017An increase in number of newly developed synthetic drugs displays bioavailability constraints because of poor water solubility. Nanosuspensions formulation may help to...
An increase in number of newly developed synthetic drugs displays bioavailability constraints because of poor water solubility. Nanosuspensions formulation may help to overwhelm these problems by increasing dissolution velocity and saturation solubility. In the present study, cyadox (Cyx) nanosuspension was successfully prepared by recrystallization based on acid-base neutralization combined with high pressure homogenization method using Polyvinylpyrrolidone K30 (PVP) as stabilizer. The nanosuspension had uniform particle distribution, excellent sedimentation rate and redispersibility. The nanosuspension significantly improved the solubility, dissolution and bioavailability. The saturation solubility of Cyx nanocrystal was higher than that of bulk Cyx and released the total drug in very short time. Further, pharmacokinetics of Cyx nanosuspension and normal suspension following oral administration was investigated in beagle dogs. Nanosuspension improved the bioavailability of Cyx which could be beneficial for intestinal bacterial infection in animals. Maximum concentration and area under concentration time curve were increased with particles size reduction which might give rise to pronounce fluctuations in plasma concentration and more intensified antibacterial effects. The terminal half-life and mean resident time of Cyx nanosuspension had also increased compared to normal Cyx suspension. In conclusion, nanosuspensions may be a suitable delivery approach to increase the bioavailability of poorly soluble drugs.
Topics: Animals; Biological Availability; Dogs; Drug Compounding; Drug Stability; Female; Male; Microscopy, Electron, Scanning; Nanoparticles; Particle Size; Povidone; Quinoxalines; Solubility; Suspensions
PubMed: 28536446
DOI: 10.1038/s41598-017-02523-4 -
STAR Protocols Mar 2023THP-1, a monocyte cell line growing in suspension, is widely used in immunology research. However, establishing suspension cell lines and performing confocal microscopy...
THP-1, a monocyte cell line growing in suspension, is widely used in immunology research. However, establishing suspension cell lines and performing confocal microscopy can be challenging. Here, we present a protocol to efficiently generate THP-1 cell lines using lentivirus and perform immunostaining and confocal microscopy. We detail steps for virus production, THP-1 cell infection and clone selection, fixing the suspension cells to the glass slide for immunostaining, and subsequent confocal microscopy. This protocol can be applied to other suspension cells. For complete details on the use and execution of this protocol, please refer to Ji et al. (2021)..
Topics: Humans; Lentivirus; THP-1 Cells; Cell Line; Microscopy, Confocal; Monocytes; Suspensions
PubMed: 36853734
DOI: 10.1016/j.xpro.2022.102032 -
Daru : Journal of Faculty of Pharmacy,... Jun 2019Nanosuspensions, liquid dispersions with nanometer size distribution, are becoming trendy in pharmaceutical practice to formulate poorly water-soluble drugs and to... (Review)
Review
BACKGROUND
Nanosuspensions, liquid dispersions with nanometer size distribution, are becoming trendy in pharmaceutical practice to formulate poorly water-soluble drugs and to enhance their bioavailability. Generally, nanosuspensions are produced in two main approaches; top-down or bottom-up. The former is based on size-reduction of large particles via milling or high pressure homogenization. The latter is focused on the mechanisms of nucleation and particle growth.
METHODS
In this review, the critical factors influencing the kinetics or dynamics of nucleation and growth are discussed. Subsequently, the mechanisms of nanosuspension instability as well as strategies for stabilization are elaborated. Furthermore, the effects of stabilizers on key parameters of instability as well as the process of choosing an appropriate stabilizer is discussed.
RESULTS
Steric and electrostatic stabilizations or combination of them is essential for nanosuspensions formulation to prevent coagulation. Accordingly, some characteristics of stabilizers play critical role on stability and optimization of nanosuspensions; i.e., HLB and concentration. Nevertheless, after reviewing various articles, it is ascertained that each formulation requires individual selection of surfactants according to the parameters of the particle surface and the medium.
CONCLUSIONS
Based on the results, application of excipients such as stabilizers requires proper optimization of type and concentration. This implies that each formulation requires its own optimization process. Graphical Abstract ᅟ.
Topics: Biological Availability; Drug Compounding; Nanoparticles; Particle Size; Static Electricity; Surface-Active Agents; Suspensions
PubMed: 30661188
DOI: 10.1007/s40199-018-00235-2 -
Advances in Colloid and Interface... Nov 2012The forces acting in colloidal suspensions and affecting their stability and aggregation kinetics are considered. The approximations used for these forces in numerical... (Review)
Review
The forces acting in colloidal suspensions and affecting their stability and aggregation kinetics are considered. The approximations used for these forces in numerical simulations and the importance of the balanced account for both colloidal forces and hydrodynamic interactions are discussed. As an example the results of direct numerical simulations of kinetics of aggregation either with account for hydrodynamic interaction between particles or without it are compared by varying the parameters of the interaction potential between particles and fraction of solid. Simulations are based on the Langevin equations with pairwise interaction between particles and take into account Brownian, hydrodynamic and colloidal forces. It is confirmed that the neglecting of hydrodynamic interaction results in an accelerated growth of aggregates. The results of numerical simulations of aggregation kinetics are compared with well known analytical solutions.
Topics: Hydrodynamics; Kinetics; Models, Theoretical; Suspensions
PubMed: 21645876
DOI: 10.1016/j.cis.2011.05.009 -
Sensors (Basel, Switzerland) Jun 2023This paper presents a method for the identification of control-related signal paths dedicated to a semi-active suspension with MR (magnetorheological) dampers, which are...
This paper presents a method for the identification of control-related signal paths dedicated to a semi-active suspension with MR (magnetorheological) dampers, which are installed in place of standard shock absorbers. The main challenge comes from the fact that the semi-active suspension needs to be simultaneously subjected to road-induced excitation and electric currents supplied to the suspension MR dampers, while a response signal needs to be decomposed into road-related and control-related components. During experiments, the front wheels of an all-terrain vehicle were subjected to sinusoidal vibration excitation at a frequency equal to 12 Hz using a dedicated diagnostic station and specialised mechanical exciters. The harmonic type of road-related excitation allowed for its straightforward filtering from identification signals. Additionally, front suspension MR dampers were controlled using a wideband random signal with a 25 Hz bandwidth, different realisations, and several configurations, which differed in the average values and deviations of control currents. The simultaneous control of the right and left suspension MR dampers made it necessary to decompose the vehicle vibration response, i.e., the front vehicle body acceleration signal, into components related to the forces generated by different MR dampers. Measurement signals used for identification were taken from numerous sensors available in the vehicle, e.g., accelerometers, suspension force and deflection sensors, and sensors of electric currents, which control the instantaneous damping parameters of MR dampers. The final identification was carried out for control-related models evaluated in the frequency domain and revealed several resonances of the vehicle response and their dependence on the configurations of control currents. In addition, the parameters of the vehicle model with MR dampers and the diagnostic station were estimated based on the identification results. The analysis of the simulation results of the implemented vehicle model carried out in the frequency domain showed the influence of the vehicle load on the absolute values and phase shifts of control-related signal paths. The potential future application of the identified models lies in the synthesis and implementation of adaptive suspension control algorithms such as FxLMS (filtered-x least mean square). Adaptive vehicle suspensions are especially preferred for their ability to quickly adapt to varying road conditions and vehicle parameters.
Topics: Suspensions; Algorithms; Computer Simulation; Vibration
PubMed: 37420933
DOI: 10.3390/s23125770 -
Archives of Physiology and Biochemistry Oct 2012The Bio-Plex(®) system utilizes xMAP technology to permit the multiplexing of up to 100 different analytes. Multiplex analysis gives researchers the ability to look at... (Review)
Review
The Bio-Plex(®) system utilizes xMAP technology to permit the multiplexing of up to 100 different analytes. Multiplex analysis gives researchers the ability to look at analytes simultaneously providing more information from less sample volume in less time than traditional immunoassay methods. Similar to ELISA, xMAP utilizes an antibody sandwich for detection but differs from ELISA in capture substrate and detection method. Rather than a flat surface, Bio-Plex(®) assays make use of differentially detectable bead sets as a substrate capturing analytes in solution and employs fluorescent methods for detection. These bead sets identify the analytes and detection antibodies are used to measure the quantity of analyte. The use of differentially detectable beads enables the simultaneous identification and quantification of many analytes in the same sample.
Topics: Animals; COS Cells; Chlorocebus aethiops; Humans; Immunoassay; Microspheres; Suspensions
PubMed: 22852821
DOI: 10.3109/13813455.2012.705301 -
Integrative Biology : Quantitative... Jun 2009The requirement for analysis of large numbers of biomolecules for drug discovery and clinical diagnostics has driven the development of low-cost, flexible and... (Review)
Review
The requirement for analysis of large numbers of biomolecules for drug discovery and clinical diagnostics has driven the development of low-cost, flexible and high-throughput methods for simultaneous detection of multiple molecular targets in a single sample (multiplexed analysis). The technique that seems most likely to satisfy all of these requirements is the multiplexed suspension (bead-based) assay, which offers a number of advantages over alternative approaches such as ELISAs and microarrays. In a bead based assay, different probe molecules are attached to different beads (of a few tens of microns in size), which are then reacted in suspension with the target sample. After reaction, the beads must be identifiable in order to determine the attached probe molecule, and thus each bead must be labelled (encoded) with a unique identifier. A large number of techniques have been proposed for encoding beads. This critical review analyses each technology on the basis of its ability to fulfil the practical requirements of assays, whilst being compatible with low-cost, high-throughput manufacturing processes and high-throughput detection methods. As a result, we identify the most likely candidates to be used for future integrated device development for practical applications.
Topics: Biological Assay; Biotechnology; Microspheres; Molecular Probe Techniques; Staining and Labeling; Suspensions
PubMed: 20023742
DOI: 10.1039/b905502a -
International Journal of Nanomedicine 2022Montelukast (MTK), a representative leukotriene receptor antagonist, is currently being investigated as a potential candidate for treating Alzheimer's disease. For...
BACKGROUND
Montelukast (MTK), a representative leukotriene receptor antagonist, is currently being investigated as a potential candidate for treating Alzheimer's disease. For potent and effective dosing in elderly patients, a parenteral prolonged delivery system is favored, with improved medication adherence with reduced dosage frequency.
PURPOSE
This study aimed to design a nanocrystalline suspension (NS)-based MTK prolonged delivery system and evaluate its pharmacokinetics profile and local tolerability following subcutaneous administration.
METHODS
To decelerate the dissolution rate, the amorphous MTK raw material was transformed into a crystalline state using a solvent-mediated transformation method and subsequently formulated into NS using a bead-milling technique. The MTK NSs were characterized by morphology, particle size, crystallinity, and in vitro dissolution profiles. The pharmacokinetic profile and local tolerability at the injection site following subcutaneous injection of MTK suspension were evaluated in rats.
RESULTS
Microscopic and physical characterization revealed that the amorphous MTK powder was lucratively transformed into a crystalline form in acidic media (pH 4). MTK crystalline suspensions with different diameters (200 nm, 500 nm, and 3 μm) were uniformly prepared using bead-milling technology, employing polysorbate 80 as suspending agent. Prepared crystalline suspensions exhibited analogous crystallinity (melting point, 150°C) and size-dependent in vitro dissolution profiles. MTK NSs with particle sizes of 200 nm and 500 nm provided a protracted pharmacokinetic profile for up to 4 weeks in rats, with a higher maximum drug concentration in plasma than the 3 μm-sized injectable suspensions. Histopathological examination revealed that MTK NS caused chronic granulomatous inflammation at the injection site, which resolved after 4 weeks.
CONCLUSION
The MTK parenteral NS delivery system is expected to be a valuable tool for treating Alzheimer's disease with extended dose intervals.
Topics: Acetates; Alzheimer Disease; Animals; Cyclopropanes; Nanoparticles; Particle Size; Quinolines; Rats; Solubility; Sulfides; Suspensions
PubMed: 36046838
DOI: 10.2147/IJN.S375888 -
Drug Delivery Dec 2021In recent years, nanocrystal technology has been extensively investigated. Due to the submicron particle size and unique physicochemical properties of nanocrystals, they... (Review)
Review
In recent years, nanocrystal technology has been extensively investigated. Due to the submicron particle size and unique physicochemical properties of nanocrystals, they overcome the problems of low drug solubility and poor bioavailability. Although the structures of nanocrystals are simple, the further development of these materials is hindered by their stability. Drug nanocrystals with particle sizes of 1∼1000 nm usually require the addition of stabilizers such as polymers or surfactants to enhance their stability. The stability of nanocrystal suspensions and the redispersibility of solid nanocrystal drugs are the key factors for the large-scale production of nanocrystal preparations. In this paper, the factors that affect the stability of drug nanocrystal preparations are discussed, and related methods for solving the stability problem are put forward.
Topics: Chemistry, Pharmaceutical; Crystallization; Drug Stability; Excipients; Hydrophobic and Hydrophilic Interactions; Molecular Weight; Nanoparticles; Particle Size; Solubility; Surface Properties; Suspensions
PubMed: 33336609
DOI: 10.1080/10717544.2020.1856224