-
International Journal of Pharmaceutics Mar 2023The aim of this work was to develop approaches to utilize whole particle distributions for both particle size and particle shape parameters to map the full range of...
The aim of this work was to develop approaches to utilize whole particle distributions for both particle size and particle shape parameters to map the full range of particle properties in a curated dataset. It is hoped that such an approach may enable a more complete understanding of the particle landscape as a step towards improving the link between particle properties and processing behaviour. A 1-dimensional principal component analysis (PCA) approach was applied to create a 'morphological distribution landscape'. A dataset of imaged APIs, intermediates and excipients encompassing particle size, particle shape (elongation, length and width) and distribution shape was curated between 2008 and 2022. The curated dataset encompassed over 200 different materials, which included over 150 different APIs, and approximately 3500 unique samples. For the purposes of the current work, only API samples were included. The morphological landscape enables differentiation of materials of equivalent size but varying shape and vice versa. It is hoped that this type of approach can be utilised to better understand the influence of particle properties on pharmaceutical processing behaviour and thereby enable scientists to leverage historical knowledge to highlight and mitigate risks associated to materials of similar morphological nature.
Topics: Particle Size
PubMed: 36804520
DOI: 10.1016/j.ijpharm.2023.122743 -
Journal of Visualized Experiments : JoVE Feb 2022The present article introduces a method for fabricating and operating a pneumatic valve to control particle concentration using a microfluidic platform. This platform...
The present article introduces a method for fabricating and operating a pneumatic valve to control particle concentration using a microfluidic platform. This platform has a three-dimensional (3D) network with curved fluid channels and three pneumatic valves, which create networks, channels, and spaces through duplex replication with polydimethylsiloxane (PDMS). The device operates based on the transient response of a fluid flow rate controlled by a pneumatic valve in the following order: (1) sample loading, (2) sample blocking, (3) sample concentration, and (4) sample release. The particles are blocked by thin diaphragm layer deformation of the sieve valve (Vs) plate and accumulate in the curved microfluidic channel. The working fluid is discharged by the actuation of two on/off valves. As a result of the operation, all particles of various magnifications were successfully intercepted and disengaged. When this technology is applied, the operating pressure, the time required for concentration, and the concentration rate may vary depending on the device dimensions and particle size magnification.
Topics: Microfluidic Analytical Techniques; Microfluidics; Particle Size
PubMed: 35188137
DOI: 10.3791/63301 -
The Science of the Total Environment Apr 2020Inhalation of playground dust-derived fine particles in schoolyards poses a risk from exposure to metal(oids) and minerals. In this work, we obtained the total...
Inhalation of playground dust-derived fine particles in schoolyards poses a risk from exposure to metal(oids) and minerals. In this work, we obtained the total concentration and bioaccessibility of metal(oids) with Gamble Solution (GS) and Artificial Lysosomal Fluid (ALF) synthetic solutions, simulating the extracellular neutral pH environment of the lung and the intracellular conditions of the macrophage, respectively. Scanning Electron Microscope (SEM), and Dynamic Light Scattering analysis (DLS) techniques were used to characterize particles with a size smaller than 2.5 μm, which can be assimilated by macrophages in the deep part of the lung. Arsenic (As), lead (Pb), copper (Cu), manganese (Mn), zinc (Zn), and iron (Fe) showed concentrations of 39.9, 147.9, 286, 1369, 2313, 112,457 mg·kg, respectively. The results indicated that all studied elements were enriched when compared to (i) local geochemical background and (ii) findings reported in other cities around the world. Bioaccessibility of metal(oids) in GS was low-moderate for most studied elements. However, in ALF assays, bioaccessibility was high among the samples: for lead (Pb = 34-100%), arsenic (As = 14.7-100%), copper (Cu = 17.9-100%), and zinc (Zn = 35-52%) possibly related to hydrophobic minerals in dust. SEM and DLS image analysis showed that playground dust particles smaller than 2.5 μm are dominant, particularly particles with a size range of 500-600 nm. The polydispersity detected in these particle sizes showed that most of them might be crystalline compounds (elongated shapes) forming agglomerates instead of combustion particles (spheres). Moreover, the circularity detected varies from 0.57 to 0.79 (low roundness), which corroborates this finding. The presence of agglomerates of ultrafine/nanoparticles containing highly bioaccessible metals in playground sites may have severe implications in children's health. Therefore, further studies are required to characterize the size distribution, structure, shape and composition of such minerals which are essential factors related to the toxicology of inhaled dust particles.
Topics: Cities; Dust; Lysosomes; Metals; Particle Size
PubMed: 31954252
DOI: 10.1016/j.scitotenv.2019.136481 -
Journal of Cosmetic Dermatology May 2022Injectable poly-l-lactic acid (PLLA) carries the risk of nodule or microlump formation. Various methods including sonication have been tried to minimize these adverse...
BACKGROUND
Injectable poly-l-lactic acid (PLLA) carries the risk of nodule or microlump formation. Various methods including sonication have been tried to minimize these adverse effects of PLLA.
AIMS
This study investigated the change in size, distribution, and properties of PLLA particles after sonication, and the duration of sonication needed to reach the ideal particle size.
METHODS AND MATERIALS
Two indicators, the average size of PLLA particles and diameter at 90%, were measured at each timepoint: at 0, 10, 60, 120, and 240 minutes of sonication. The characteristics and particle shape were assessed at 0 and 240 minutes.
RESULTS
The average particle size and the diameter at 90% decreased drastically until 10 minutes of sonication and then increased slightly at 60 minutes. After 60 minutes, the average size and the diameter at 90% gradually decreased over time and reached 42.2 μm and 75.7 μm, respectively, at 120 minutes. After 240 minutes of sonication, the average particle size was 35.9 μm, much smaller than the smallest proper size required (40 μm). Standard deviation decreased gradually over time, which means that a more even distribution was obtained. Crystalline remnants were significantly less left with 120 minutes sonication compared to those with 120 minutes hydration only. PLLA particles were more cracked at the center, and microcrystals were more loosely distributed at the periphery after 120 minutes sonication.
CONCLUSION
Sonication help reduce the average size of PLLA particles and achieve more even distribution. Therefore, we believe sonication may attribute to the safer use of PLLA.
Topics: Humans; Particle Size; Polyesters; Sonication
PubMed: 34423574
DOI: 10.1111/jocd.14392 -
Applied Biochemistry and Biotechnology Jun 2023Enzymatic hydrolysis (EH) of cellulosic biomass needs tremendous technological advancement so as to efficiently convert cellulosic biomass into renewable fuels and...
Enzymatic hydrolysis (EH) of cellulosic biomass needs tremendous technological advancement so as to efficiently convert cellulosic biomass into renewable fuels and commodity chemicals. Therefore, development of highly improved process engineering techniques is inevitable to reduce the processing cost of the fluids in the reactor. In this investigation, effect of mixing and particle size on the EH of microcrystalline cotton cellulose (MCC) has been investigated by using a spatially averaged low-dimensional two-mode mixing (TMM) model. The model simulations were carried out for the average particle sizes of MCC ranging from 0.78 to 25.52 μm and mixing speed of η → 0 (very high) to η → 1000 (very low). The effects of mixing and particle size on the formation of glucose and reducing sugar (RS) have been quantified by exploiting the rigorous multistep reaction kinetics and TMM model. To access the bond-breaking ability, its effects on the degree of polymerization (DP) was also analyzed. The results deduced that increase in mixing limitations and reduction in particle size imparts a significant increase in glucose and RS yield while decreasing the DP drastically. Thus, our simulations reveal that while η → 1000 economizes the process by reducing the energy requirements, reduction in particle size can be beneficial for reducing the residence time in the depolymerization of MCC to fuels and chemicals.
Topics: Particle Size; Kinetics; Cellulose; Textiles; Glucose; Hydrolysis
PubMed: 36633758
DOI: 10.1007/s12010-022-04290-z -
The International Journal of... 2021To evaluate the physical and mechanical properties of maxillofacial silicone elastomers following the incorporation of a specific particle size and concentration of...
PURPOSE
To evaluate the physical and mechanical properties of maxillofacial silicone elastomers following the incorporation of a specific particle size and concentration of nano-titanium dioxide (TiO) and nano-zinc oxide (ZnO).
MATERIALS AND METHODS
Nano-TiO and nano-ZnO of 20-nm and 40-nm particle sizes and in 1% and 2% concentrations were chosen. Silicone elastomer samples were prepared according to the manufacturer's recommendations. The nano-oxides were incorporated via hand spatulation. The samples were subsequently tested for hardness and color stability and were then subjected to aging in an aging chamber for 1,008 hours, following which they were again evaluated for hardness, color stability, and surface roughness.
RESULTS
A significant change was noted in the physical and mechanical properties post-aging in all the groups. The samples with nano-TiO of 40-nm particle size/2% concentration had the highest hardness, while color stability and surface roughness were higher in samples with nano-TiO of 20-nm particle size/1% and 2% concentrations, respectively.
CONCLUSION
It can be concluded that 20-nm nano-TiO particles best maintain the ideal properties of maxillofacial silicone elastomers and can potentially be used as alternative opacifiers when mixed with A-2186 maxillofacial silicone elastomers.
Topics: Color; Materials Testing; Maxillofacial Prosthesis; Oxides; Particle Size; Silicone Elastomers
PubMed: 33570520
DOI: 10.11607/ijp.6593 -
International Journal of Pharmaceutics Apr 2021The physical characteristics of raw materials determine powder compression and compaction performance as relevant in pharmaceutical processes. For instance, the...
The physical characteristics of raw materials determine powder compression and compaction performance as relevant in pharmaceutical processes. For instance, the influence of initial particle size on powder compression and the resulting strength of specimen are highly complex and are still not sufficiently understood. Existing studies are often limited to materials with well-defined deformation behaviour, such as purely brittle or ductile. However, the deformation behaviour of active pharmaceutical ingredients (APIs) is often more complex. In this study, the influence of initial particle size on powder compressibility and compactibility is systematically characterized by consideration of in-die compressibility, specific energies, quick elastic recovery, tablet porosity and, tensile strength for the binder microcrystalline cellulose and three APIs. The decrease of particle size leads to an increase of the resistance against compression by trend and probably to a different contribution of the acting deformation mechanisms. The compactibility is increased with decreasing particle size because of the increasing number of bonds in a cross-sectional area of the tablet, as found by the application of the model of Rumpf. Furthermore, it is found that the model of Rumpf combined with the JKR model provides a meaningful property function to estimate tablet tensile strength.
Topics: Chemistry, Pharmaceutical; Particle Size; Porosity; Powders; Tablets; Tensile Strength
PubMed: 33647406
DOI: 10.1016/j.ijpharm.2021.120424 -
Journal of the American Chemical Society Mar 2022Nanoparticle assembly is a complex and versatile method of generating new materials, capable of using thousands of different combinations of particle size, shape,...
Nanoparticle assembly is a complex and versatile method of generating new materials, capable of using thousands of different combinations of particle size, shape, composition, and ligand chemistry to generate a library of unique structures. Here, a history of particle self-assembly as a strategy for materials discovery is presented, focusing on key advances in both synthesis and measurement of emergent properties to describe the current state of the field. Several key challenges for further advancement of nanoparticle assembly are also outlined, establishing a roadmap of critical research areas to enable the next generation of nanoparticle-based materials synthesis.
Topics: Ligands; Nanoparticles; Particle Size
PubMed: 35171596
DOI: 10.1021/jacs.1c12335 -
Pharmaceutical Research Dec 2022Spray dried dispersion particle size is a critical quality attribute that impacts bioavailability and manufacturability of the spray drying process and final dosage...
Spray dried dispersion particle size is a critical quality attribute that impacts bioavailability and manufacturability of the spray drying process and final dosage form. Substantial experimentation has been required to relate formulation and process parameters to particle size with the results limited to a single active pharmaceutical ingredient (API). This is the first study that demonstrates prediction of particle size independent of API for a wide range of formulation and process parameters at pilot and commercial scale. Additionally we developed a strategy with formulation and target particle size as inputs to define a set of "first to try" process parameters. An ensemble machine learning model was created to predict dried particle size across pilot and production scale spray dryers, with prediction errors between -7.7% and 18.6% (25th/75th percentiles) for a hold-out evaluation set. Shapley additive explanations identified how changes in formulation and process parameters drove variations in model predictions of dried particle size and were found to be consistent with mechanistic understanding of the particle formation process. Additionally, an optimization strategy used the predictive model to determine initial estimates for process parameter values that best achieve a target particle size for a provided formulation. The optimization strategy was employed to estimate process parameters in the hold-out evaluation set and to illustrate selection of process parameters during scale-up. The results of this study illustrate how trained regression models can reduce the experimental effort required to create an in-silico design space for new molecules during early-stage process development and subsequent scale-up.
Topics: Chemistry, Pharmaceutical; Particle Size; Powders
PubMed: 35986124
DOI: 10.1007/s11095-022-03370-3 -
Journal of Nanoscience and... Aug 2018In the face of a large number of insoluble drugs, the development of nanocrystals is effective in destroying the limits of poorly soluble drug applications and becoming... (Review)
Review
In the face of a large number of insoluble drugs, the development of nanocrystals is effective in destroying the limits of poorly soluble drug applications and becoming an indispensable route of drug delivery in the pharmaceutical industry. In addition, the proposed delivery goal is to provide more convenience and benefits and the number of researchers who are developing a number of advanced technologies try to use improved nano-drugs to improve the bioavailability of drug, drug dissolution velocity and solubility. Previously, more mature study has been done, for example, preparation of nanocrystals, the problems of safety, the route of administration and so on. This review systematically dwells upon several of the current nanocrystals technologies for target delivery by different modification technologies, such as magnetic nanocrystals, PEG and PEGylated chitosan modified nanocrystals, cationic nanocrystals and pluronic modified nanocrystals. Subsequently, the effects of surface charge and particle size on the drug targeted administration was analyzed. This review will provide a new insight for improving stability and controllability of the nanocrystals, and promote the nanocrystals technology development in targeting drug delivery.
Topics: Biological Availability; Drug Delivery Systems; Nanoparticles; Particle Size; Pharmaceutical Preparations; Solubility
PubMed: 29458570
DOI: 10.1166/jnn.2018.15421