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Cells Apr 2022The aim of our research was to describe the structure and growth potential of a cell suspension of the tree fern . Experiments were performed on an established cell...
The aim of our research was to describe the structure and growth potential of a cell suspension of the tree fern . Experiments were performed on an established cell suspension with ½ MS medium supplemented with 9.05 µM 2,4-D + 0.88 µM BAP. In the experiments, attention was paid to the microscopic description of cell suspension, evaluation of cell growth dependent on the initial mass of cells and organic carbon source in the medium, the length of the passage, the content of one selected flavonoid in the post-culture medium, nuclear DNA content, ethylene production, and the antimicrobial value of the extract. For a better understanding of the cell changes that occurred during the culture of the suspension, the following structures of the cell were observed: nucleus, lipid bodies, tannin deposits, starch grains, cell walls, primary lamina, and the filaments of metabolites released into the medium. The nuclear DNA content (acriflavine-Feulgen staining) of cell aggregates distinctly indicated a lack of changes in the sporophytic origin of the cultured cell suspension. The physiological activity of the suspension was found to be high because of kinetics, intensive production of ethylene, and quercetin production. The microbiological studies suggested that the cell suspension possessed a bactericidal character against microaerobic Gram-positive bacteria. A sample of the cell suspension showed bacteriostatic activity against aerobic bacteria.
Topics: 2,4-Dichlorophenoxyacetic Acid; Anti-Bacterial Agents; Biotechnology; Ethylenes; Ferns; Suspensions
PubMed: 35563701
DOI: 10.3390/cells11091396 -
International Journal of Antimicrobial... Dec 2023To investigate the potential impact of clinical characteristics and the Chinese race on posaconazole pharmacokinetics in patients using an integrated population...
Meta-pharmacokinetic analysis of posaconazole following dosing of oral suspension, delayed-release tablet, and intravenous infusion in patients vs. healthy volunteers: Impact of clinical characteristics and race.
OBJECTIVES
To investigate the potential impact of clinical characteristics and the Chinese race on posaconazole pharmacokinetics in patients using an integrated population pharmacokinetic model for posaconazole oral suspension (SUS), delayed-release tablet (DR-tablet), and intravenous (IV) infusion that was developed in healthy volunteers (HV).
METHODS
1046 concentrations from 105 prospectively studied Caucasian patients receiving either of the three posaconazole formulations were pooled with 3898 concentrations from 182 HV. Clinical characteristics were tested for significance. The impact of Chinese race was assessed using 292 opportunistic samples from 80 Chinese patients receiving SUS.
RESULTS
Bioavailability of SUS (F) in patients decreased from 38.2% to 24.6% when the dose was increased from 100 mg to 600 mg. Bioavailability of DR-tablet (F) was 59% regardless of dose. Mucositis, diarrhoea, administration through a nasogastric tube, and concomitant use of proton pump inhibitors or metoclopramide reduced F by 61%, 36%, 44%, 48%, and 29%, respectively, putting patients with these characteristics at increased risk of inadequate exposure. Clearance decreased from 7.0 to 5.1 L/h once albumin levels were <30 g/L. Patients showed an 84.4% larger peripheral volume of distribution (V) and 67.5% lower intercompartmental clearance (Q) compared with HV. No racial difference could be identified.
CONCLUSIONS
Pharmacokinetics of posaconazole in patients differ considerably to those in HV, with altered F that is also impacted by clinical covariates, an F similar to fasted conditions in HV, and altered parameters for clearance, V, and Q. There was no evidence to indicate that Chinese patients require a different dose to Caucasian patients.
Topics: Humans; Infusions, Intravenous; Antifungal Agents; Tablets; Triazoles; Biological Availability; Suspensions; Administration, Oral
PubMed: 37806462
DOI: 10.1016/j.ijantimicag.2023.106995 -
Advances in Colloid and Interface... Nov 2022The electroacoustic technique has been successfully used to determine the zeta potential of concentrated aqueous suspensions for over thirty years. This article reviews... (Review)
Review
The electroacoustic technique has been successfully used to determine the zeta potential of concentrated aqueous suspensions for over thirty years. This article reviews its use in mineral processing, ceramics, zeolites, and other industrial minerals and in particular identifies the isoelectric points of these materials, as this parameter is crucial for determining colloidal stability and hence subsequent processing. Some benefits of this technique over the traditional electrokinetic measurement techniques are also highlighted. Finally, the application of the technique to polymer lattices is summarized.
Topics: Suspensions; Zeolites; Water; Polymers
PubMed: 36209685
DOI: 10.1016/j.cis.2022.102778 -
BMC Pharmacology & Toxicology Feb 2023The study was aimed at evaluating the bioequivalence and safety of oseltamivir phosphate for suspension, provided by Shenzhen Beimei Pharmaceutical Co. Ltd. and... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
The study was aimed at evaluating the bioequivalence and safety of oseltamivir phosphate for suspension, provided by Shenzhen Beimei Pharmaceutical Co. Ltd. and manufactured by Hetero Labs Limited, and the reference product TAMIFLU® in healthy Chinese subjects.
METHODS
A single-dose, randomized, two-phase, self-crossed model was adopted. Among 80 healthy subjects, 40 subjects in the fasting group and 40 subjects in the fed group. Subjects in the fasting group were randomized into two sequences according to the proportion of 1:1, each given 75 mg/12.5 mL of Oseltamivir Phosphate for Suspension or TAMIFLU®, and cross-administered after 7 days. Postprandial group is the same as fasting group.
RESULTS
The T of TAMIFLU® and Oseltamivir Phosphate for Suspension in the fasting group were 1.50 h and 1.25 h, which in the fed group were both 1.25 h. Geometrically adjusted mean ratios of the PK parameters of Oseltamivir Phosphate for Suspension along with TAMIFLU® under fasting and postprandial conditions were in the range of 80.00-125.00% at the 90% confidence interval (CI). The 90% CI of C, AUC, AUC for fasting group and postprandial group were (92.39,106.50), (94.26,100.67), (94.32,100.89) and (93.61,105.83),(95.64,100.19),(96.06,102.66). Among the subjects on medication, a total of 18 subjects reported 27 adverse events, all of which were treatment-emergent adverse events (TEAEs), six of these TEAEs were rated as grade 2 in severity and the rest were as grade 1. The number of TEAEs in the test product and the reference product were 14,13 respectively.
CONCLUSION
Two Oseltamivir phosphate for suspensions are safe and bioequivalent.
Topics: Humans; Oseltamivir; Therapeutic Equivalency; Suspensions; Cross-Over Studies; Area Under Curve; Fasting; Healthy Volunteers; Phosphates; Tablets
PubMed: 36810140
DOI: 10.1186/s40360-023-00646-1 -
Molecular Pharmaceutics Mar 2022Developing biological formulations to maintain the chemical and structural integrity of therapeutic antibodies remains a significant challenge. Monoclonal antibody (mAb)...
Developing biological formulations to maintain the chemical and structural integrity of therapeutic antibodies remains a significant challenge. Monoclonal antibody (mAb) crystalline suspension formulation is a promising alternative for high concentration subcutaneous drug delivery. It demonstrates many merits compared to the solution formulation to reach a high concentration at the reduced viscosity and enhanced stability. One main challenge in drug development is the lack of high-resolution characterization of the crystallinity and stability of mAb microcrystals in the native formulations. Conventional analytical techniques often cannot evaluate structural details of mAb microcrystals in the native suspension due to the presence of visible particles, relatively small crystal size, high protein concentration, and multicomponent nature of a liquid formulation. This study demonstrates the first high-resolution characterization of mAb microcrystalline suspension using magic angle spinning (MAS) NMR spectroscopy. Crystalline suspension formulation of pembrolizumab (Keytruda, Merck & Co., Inc., Kenilworth, NJ 07033, U.S.) is utilized as a model system. Remarkably narrow C spectral linewidth of approximately 29 Hz suggests a high order of crystallinity and conformational homogeneity of pembrolizumab crystals. The impact of thermal stress and dehydration on the structure, dynamics, and stability of these mAb crystals in the formulation environment is evaluated. Moreover, isotopic labeling and heteronuclear C and N spectroscopies have been utilized to identify the binding of caffeine in the pembrolizumab crystal lattice, providing molecular insights into the cocrystallization of the protein and ligand. Our study provides valuable structural details for facilitating the design of crystalline suspension formulation of Keytruda and demonstrates the high potential of MAS NMR as an advanced tool for biophysical characterization of biological therapeutics.
Topics: Antibodies, Monoclonal, Humanized; Magnetic Resonance Spectroscopy; Molecular Conformation; Proteins; Suspensions
PubMed: 35107019
DOI: 10.1021/acs.molpharmaceut.1c00915 -
Sensors (Basel, Switzerland) Oct 2021Active suspension control strategies are a top priority in active suspension system. The current research on active suspension control strategies is mostly focused on...
Active suspension control strategies are a top priority in active suspension system. The current research on active suspension control strategies is mostly focused on two-axle vehicles, and there is less research investigating multi-axle vehicles. Additionally, their effective implementation is dependent on accurate mathematical models, and most of them adopt force feedback control, which is vulnerable to external interference. To solve these problems, this paper proposes an active suspension control strategy based on Inertial Measurement Unit. The multi-axle emergency rescue vehicle is made to be equivalent to a 3-degrees-of-freedom parallel mechanism by using the method of grouping and interconnecting the suspension units of the whole vehicle. The attitude change of the vehicle body was transformed into the servo actuator's displacement by solving the inverse solution of the parallel mechanism position and the action of the servo actuator was driven in reverse according to the displacement obtained. In this way, the vehicle body attitude can be compensated, and the ride comfort and the handling stability of the vehicle can be improved. To verify the effectiveness of the control strategy proposed, the three-axle six vehicle was taken as the research object, the position inverse solution of its equivalent 3-degrees-of-freedom parallel mechanism was deduced, and a high-pass filter was designed. The three-axle vehicle experiment platform integrating active suspension and hydro-pneumatic suspension was built, and the gravel road and slope road experiments were carried out and the results compared with those obtained with hydro-pneumatic suspension. The experiment results showed that, compared with hydro-pneumatic suspension, the active suspension control strategy based on Inertial Measurement Unit proposed in this paper can not only stabilize the body attitude, but also effectively suppress body vibration, improving the ride comfort and handling stability of the vehicle significantly.
Topics: Equipment Design; Suspensions; Vibration
PubMed: 34696090
DOI: 10.3390/s21206877 -
International Journal of Pharmaceutical... 2020Allopurinol is an orally administered inhibitor of xanthine oxidase used primarily in the treatment of hyperuricemia associated with gout. Allopurinol reduces serum...
Allopurinol is an orally administered inhibitor of xanthine oxidase used primarily in the treatment of hyperuricemia associated with gout. Allopurinol reduces serum and urinary uric acid concentrations. Its use should be individualized for each patient. The dosage of allopurinol to accomplish full control of gout and to lower serum uric acid to normal or near-normal levels varies with the severity of the disease, and needs to be flexible to permit precise, customized dose titration for individual patients. This flexibility is readily achieved using an oral liquid dosage form. However, no commercial liquid dosage form of allopurinol currently exists. Allopurinol is commercially available as 100-mg and 300-mg scored tablets. An extemporaneously compounded suspension from pure drug powder or commercial tablets would provide a convenient option to meet unique patient needs. The purpose of this study was to determine the physicochemical stability of extemporaneously compounded allopurinol suspensions in the PCCA Base SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. The study design included two allopurinol concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust stability-indicating ultra-performance liquid chromatography assay for the determination of the chemical stability of allopurinol in SuspendIt was developed and validated. Suspensions of allopurinol were prepared in SuspendIt at 10.0-mg/mL and 20.0-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in plastic amber prescription bottles at two temperature conditions (5°C and 25°C). Samples were assayed initially and at the following time points: 7 days, 14 days, 30 days, 45 days, 60 days, 88 days, 120 days, and 182 days. Physical data such as pH, viscosity, and appearance were also noted. All measurements were obtained in triplicate. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period. The study showed that allopurinol concentrations did not go below 93% of the label claim (initial drug concentration) at both temperatures studied. Viscosity and pH values also did not change significantly. This study demonstrates that allopurinol is physically and chemically stable in SuspendIt for 180 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for allopurinol in a liquid dosage form, with an extended beyond-use-date to meet patient needs.
Topics: Administration, Oral; Allopurinol; Chromatography, High Pressure Liquid; Drug Compounding; Drug Stability; Drug Storage; Humans; Suspensions; Uric Acid
PubMed: 32886640
DOI: No ID Found -
Asian Pacific Journal of Cancer... 2013Recently, use of natural products available from marine sources, and especially algae products, are receiving more attention. Scientific evidence for claimed... (Review)
Review
Recently, use of natural products available from marine sources, and especially algae products, are receiving more attention. Scientific evidence for claimed nutraceutical and therapeutical effects of one such marine algae product, fucoxanthin, is discussed in this paper with a summary of the currently available literature regarding its antioxidant, anti-obesity and anticancer activities. It is safe for use in humans, but as it has poor solubility a nano-suspension mode of delivery may be adopted to improve efficacy of supplements. We conclude from our literature review that the marine algae product fucoxanthin has significant antioxidant, anti-obesity and anticancer activity with established mechanisms of action.
Topics: Antineoplastic Agents; Drug Delivery Systems; Humans; Marine Biology; Nanoparticles; Neoplasms; Pharmaceutical Preparations; Rhodophyta; Suspensions; Xanthophylls
PubMed: 23725114
DOI: 10.7314/apjcp.2013.14.4.2213 -
Scientific Reports Aug 2023Colloidal silica grouting is a ground improvement technique capable of stabilizing weak problematic soils and achieving large reductions in soil hydraulic conductivities...
Colloidal silica grouting is a ground improvement technique capable of stabilizing weak problematic soils and achieving large reductions in soil hydraulic conductivities for applications including earthquake-induced liquefaction mitigation and groundwater flow control. In the conventional approach, chemical accelerants are added to colloidal silica suspensions that are introduced into soils targeted for improvement and the formation of a semi-solid silica gel occurs over time at a rate controlled by suspension chemistry and in situ geochemical conditions. Although the process has been extensively investigated, controlling the rate of gel formation in the presence of varying subsurface conditions and the limited ability of conventional methods to effectively monitor the gel formation process has posed practical challenges. In this study, a biomediated soil improvement process is proposed which utilizes enriched fermentative microorganisms to control the gelation of colloidal silica grouts through solution pH reductions and ionic strength increases. Four series of batch experiments were performed to investigate the ability of glucose fermenting microorganisms to be enriched in natural sands to induce geochemical changes capable of mediating silica gel formation and assess the effect of treatment solution composition on pH reduction behaviors. Complementary batch and soil column experiments were subsequently performed to upscale the process and explore the effectiveness of chemical, hydraulic, and geophysical methods to monitor microbial activity, gel formation, and engineering improvements. Results demonstrate that fermentative microorganisms can be successfully enriched and mediate gel formation in suspensions that would otherwise remain highly stable, thereby forgoing the need for chemical accelerants, increasing the reliability and control of colloidal silica grouting, enabling new monitoring approaches, and affording engineering enhancements comparable to conventional colloidal silica grouts.
Topics: Fermentation; Reproducibility of Results; Silica Gel; Suspensions; Soil
PubMed: 37648736
DOI: 10.1038/s41598-023-41402-z -
Journal of Ocular Pharmacology and... 2022To compare ocular pharmacokinetics (PK), systemic absorption, and injectability of triamcinolone acetonide (TA) suprachoroidal (SC) and intravitreal (IVT) suspensions....
Suprachoroidal Injection of Triamcinolone Acetonide Suspension: Ocular Pharmacokinetics and Distribution in Rabbits Demonstrates High and Durable Levels in the Chorioretina.
To compare ocular pharmacokinetics (PK), systemic absorption, and injectability of triamcinolone acetonide (TA) suprachoroidal (SC) and intravitreal (IVT) suspensions. New Zealand White (NZW) rabbits received a bilateral injection of 4 mg TA injectable suspension, TRI (TRIESENCE ; Alcon) through either microneedle-based SC or standard IVT injection. Another group of NZW rabbits received a bilateral SC injection (4 mg) of either TRI or a proprietary TA suspension for SC use, CLS-TA (Clearside Biomedical). Blood and ocular tissues were analyzed for TA over 3 months. Separately, injectability of TRI and CLS-TA through a proprietary SC delivery system (SCS Microinjector; Clearside Biomedical) was compared using microinjector syringe-plunger glide force measurement. Suprachoroidal delivery of TRI, compared with IVT-TRI, resulted in ∼12-fold higher exposure in the retinal pigment epithelium-choroid-sclera, and comparable exposure in the retina. Conversely, SC-TRI, compared to IVT-TRI, resulted in 460-, 34-, and 22-fold lower exposure in the lens, iris-ciliary body, and vitreous humor, and negligible exposure in the aqueous humor. SC injection of either CLS-TA or TRI resulted in comparable and sustained ocular TA levels. Plasma TA levels were generally undetectable in both studies. A significantly greater and more variable glide force was measured for TRI vs. CLS-TA. Suprachoroidal delivery of TA enabled high and durable TA levels targeted to the chorioretina with limited anterior segment exposure. SC delivery of either CLS-TA or TRI resulted in comparable ocular PK profiles with low systemic exposure; however, CLS-TA required lower and less variable glide force than TRI, potentiating more consistent, controlled administration.
Topics: Animals; Choroid; Glucocorticoids; Rabbits; Retina; Suspensions; Triamcinolone Acetonide
PubMed: 35404132
DOI: 10.1089/jop.2021.0090