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European Journal of Pharmaceutics and... Mar 2022Rapid precorneal loss of topically applied eye drops limits ocular drug absorption. Controlling release and precorneal residence properties of topical formulations may...
Rapid precorneal loss of topically applied eye drops limits ocular drug absorption. Controlling release and precorneal residence properties of topical formulations may improve ocular drug bioavailability and duration of action. In this study, we evaluated in vivo ocular pharmacokinetics of dexamethasone in rabbits after application of a drug solution (0.01%), suspension (Maxidex® 0.1%), and hydrogels of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AAc) copolymers. The rabbits received a single eyedrop (solution or suspension) or dexamethasone-loaded hydrogel topically. Dexamethasone in tear fluid was sampled with glass capillaries and quantitated by LC-MS/MS. Higher dexamethasone exposure (AUC) in the tear fluid was observed with the suspension (≈3.6-fold) and hydrogel (12.8-fold) as compared to the solution. During initial 15 min post-application, the highest AUC of dissolved dexamethasone was seen after hydrogel application (368 min*µg/mL) followed by suspension (109.9 min*µg/mL) and solution (28.7 min*µg/mL. Based on kinetic simulations, dexamethasone release from hydrogels in vivo and in vitro is comparable. Our data indicate that prolonged exposure of absorbable dexamethasone in tear fluid is reached with hydrogels and suspensions. Pharmacokinetic understanding of formulation behavior in the lacrimal fluid helps in the design of dexamethasone delivery systems with improved ocular absorption and prolonged duration of action.
Topics: Animals; Chromatography, Liquid; Dexamethasone; Drug Liberation; Hydrogels; Kinetics; Rabbits; Suspensions; Tandem Mass Spectrometry
PubMed: 35121080
DOI: 10.1016/j.ejpb.2022.01.005 -
Scientific Reports May 2023The accuracy of blood group identification is the basis of blood transfusion safety. In order to increase the detection rate of weak agglutination, unexpected antibodies...
The accuracy of blood group identification is the basis of blood transfusion safety. In order to increase the detection rate of weak agglutination, unexpected antibodies (UAb) and blood subtypes for pre-transfusion testing, the blood group screening process of automated blood group analyzer (ABGA) is ameliorated by introducing one static step and establishing a suspension static method (SSM). One static step was introduced in the blood group screening process of ABGA and three static time conditions were designed: 300 s, 400 s and 500 s, from which the optimal static time was selected and SSM was established; By comparing the detection of weak agglutination and UAb before and after the application of SSM, the feasibility and effect of suspension static method were verified and evaluated. The last two steps of the automatic blood group screening process were replaced with static, light centrifugation and imaging. The optimal static time parameter was selected as 400 s and SSM was established; After the application of SSM, it was verified that: (1) The detection level of weak antibodies (anti-A and anti-B) and weak antigens (weak D phenotype) could be improved by SSM, including antibodies in plasma of known type O samples with 0, 2, 4, 8, 16 and 32 times serial dilutions(simulating weak anti-A and weak anti-B), weak antibodies (anti-B) in plasma of one normal A-type sample and weak antigens on red blood cells (RBC) of 5 weak D phenotype samples (weak D antigen); (2) Three blood donor samples (type A, O and B) with known UAb were detected by SSM. The results showed that SSM could detect both weak antibodies (anti-A and anti-B) and UAb; (3) SSM was applied to detect the samples of 3 AB and 3 subtype B blood donors and the blood subtypes could be clearly detected; (4) The number of screening samples was 95,314 and 106,814 before SSM (2018) and after (2020) the application of SSM and the positive rate of UAb (63/95,314 and 187/106,814) increased after SSM, discrepancy of which was statistically significant (χ = 48.42, P < 0.01). The above results demonstrate that SSM of ABGA is conducive to the detection of weak agglutination, UAb and blood subtypes in blood samples, which can improve the sensitivity of blood group detection and ensure the safety of clinical blood transfusion to a certain extent.
Topics: Humans; Blood Group Antigens; Suspensions; Antibodies; Erythrocytes; Blood Donors
PubMed: 37160939
DOI: 10.1038/s41598-023-34495-z -
Medical Principles and Practice :... 2021The objectives were to prepare, characterize, and evaluate different ibuprofen (IBU) nanosuspensions.
INTRODUCTION
The objectives were to prepare, characterize, and evaluate different ibuprofen (IBU) nanosuspensions.
METHODS
The nanosuspensions produced by ultrahomogenization were compared with a marketed IBU suspension for particle size, in vitro dissolution, and in vivo absorption. Five groups of rabbits were orally administered with 25 mg/kg of IBU nanosuspension, nanoparticles, unhomogenized suspension, marketed product, and untreated suspension. A sixth group received 5 mg/kg IBU intravenously. Blood samples obtained were analyzed by chromatography.
RESULTS
The nanosuspensions showed significant decrease in particle size. Polyvinylpyrrolidone (PP) K30 profoundly increased aqueous solubility of IBU. Addition of Tween 80 (TW), in equal amount as PP (IBU:PP:TW, 1:2:2 w/w), resulted in much smaller particle size and better dissolution rate. The Cmax values achieved were 14.8 ± 1.64, 11.1 ± 1.37, 9.01 ± 0.761, 7.03 ± 1.38, and 3.23 ± 1.03 μg/mL, and the tmax values were 36 ± 8.2, 39 ± 8.2, 100 ± 17.3, 112 ± 15, and 105 ± 17 min for the nanosuspension, nanoparticle, unhomogenized suspension, marketed IBU suspension, and untreated IBU suspension in water, respectively. Bioavailability of the different formulations relative to the marketed suspension was found to be in the following sequence: nanosuspension > unhomogenized suspension > nanoparticles > untreated IBU suspension.
CONCLUSION
IBU/PP/TW nanosuspension showed enhanced in vitro and in vivo performance as compared to the marketed product. Nanosuspensions prepared by the ultrahigh-pressure homogenization technique can be used as a good formulation strategy to enhance the rate and extent of absorption of poorly soluble drugs.
Topics: Animals; Biological Availability; Chromatography, High Pressure Liquid; Ibuprofen; Nanostructures; Nanotechnology; Rabbits; Solubility; Solvents; Suspensions
PubMed: 33823524
DOI: 10.1159/000516299 -
Journal of Medical Ethics Aug 2022The rare but severe cerebral venous thrombosis occurring in some AstraZeneca vaccine recipients has prompted some governments to suspend part of their COVID-19...
The rare but severe cerebral venous thrombosis occurring in some AstraZeneca vaccine recipients has prompted some governments to suspend part of their COVID-19 vaccination programmes. Such suspensions have faced various challenges from both scientific and ethical angles. Most of the criticisms against such suspensions follow a consequentialist approach, arguing that the suspension will lead to more harm than benefits. In this paper, I propose a rights-based argument against the suspension of the vaccine rollouts amid this highly time-sensitive combat of COVID-19. I argue that by suspending a vaccine rollout, a government infringes people's right to take the risks they deem worth taking for their health. I also consider four potential objections to my argument and explain why none of them undermines my argument.
Topics: COVID-19; COVID-19 Vaccines; Humans; Suspensions; Vaccination; Vaccines
PubMed: 34253621
DOI: 10.1136/medethics-2021-107545 -
PloS One 2023The purpose of this study was to assess the differences in muscle activation (EMG) and body weight distribution (%BW) between suspension (TRX™ push-up and TRX™...
The purpose of this study was to assess the differences in muscle activation (EMG) and body weight distribution (%BW) between suspension (TRX™ push-up and TRX™ inverted row) and conventional exercises (bench press and lying barbell row) using different contraction types (isometric and isotonic) and position variations (feet on the ground [FG] and feet on suspension device [FD]). It was also used to determine the intensity of the force applied to the straps of the suspension device corresponding to one repetition maximum (1-RM). Twelve male athletes (ages-24.5±4.2 years (mean±standard deviation [SD]); Height-181.0±6.8 cm; body mass-83.08±6.81 kg) participated in this study. Two suspension devices were used, one for the FD variation and one for the FG variation pectoralis major (PM) and triceps brachii (TRI) activations were assessed during the TRX™ push-up and bench press exercises. Transversus trapezius (TRA) and biceps brachii (BB) activations were assessed during the TRX™ inverted row and lying barbell row exercises. The results showed significant differences between exercises (FG and FD variations of TRX™ push-up and bench press) in PM activities (isometric and isotonic) (p≤0.05). However, these differences were only observed during isometric TRI activation (p≤0.05). In the FG and FD variations of the TRX™ inverted row and lying barbell row exercises, there were only differences in the isometric contractions of the TRA and BB (p≤0.05). In the suspension device of push-ups and inverted row for the FD variations, 70.5% and 72.64% of 1-RM intensity were obtained, respectively. Similar responses to training intensities and muscle activations can be obtained in suspension exercises and conventional exercises. FD variations of suspension exercises can be more effective in terms of muscle activations than FG variations, and isotonic suspension exercises increase exercise intensity more than isometric suspension exercises.
Topics: Male; Humans; Exercise; Exercise Therapy; Foot; Pectoralis Muscles; Isometric Contraction; Suspensions
PubMed: 37738266
DOI: 10.1371/journal.pone.0291608 -
European Journal of Hospital Pharmacy :... Nov 2022In children, supraventricular tachycardia is the most common form of arrhythmia, and propafenone is an effective class Ic antiarrhythmic agent used in this population....
OBJECTIVES
In children, supraventricular tachycardia is the most common form of arrhythmia, and propafenone is an effective class Ic antiarrhythmic agent used in this population. No suitable paediatric-specific, dosing-flexible preparation is available in Taiwan. The objective of this study was to develop a formulation of propafenone oral suspension prepared from commercially available propafenone tablets and commercially available oral syrup vehicles for related patients.
METHODS
An oral suspension of propafenone hydrochloride at a concentration of 10 mg/mL was prepared by mixing finely grounded propafenone hydrochloride tablets and a 1:1 mixture of Ora-Plus and Ora-Sweet. The beyond-use date was determined by analysing the samples stored at room temperature or 2-8℃ at time 0 and on days 7, 14, 21, 28, 35, 42, 56, and 90. Parameters to be inspected included appearance, pH measurement, high-performance liquid chromatography analysis, and microbial limit tests.
RESULTS
On the basis of the physicochemical and microbial stability results, the 10 mg/mL oral suspension of propafenone hydrochloride was stable at 2-8℃ and room temperature for at least 90 days. The suspension did not exhibit significant changes in drug concentration or pH level at any time point. Moreover, no apparent changes or microbial contaminations were observed for at least 90 days.
CONCLUSIONS
Propafenone hydrochloride in a 10 mg/mL oral suspension prepared by diluting fine powder with a 1:1 mixture of Ora-Plus and Ora-Sweet and stored in high-density polyethylene bottles and has a beyond-use date of 90 days when stored at 2-8℃ or room temperature. This finding enables us to improve the accuracy of dosage administration and reduce the risk of medication errors affecting the paediatric population.
Topics: Humans; Child; Drug Stability; Propafenone; Drug Compounding; Powders; Polyethylene; Administration, Oral; Pharmaceutical Vehicles; Suspensions; Arrhythmias, Cardiac
PubMed: 33608396
DOI: 10.1136/ejhpharm-2020-002567 -
Cytometry. Part a : the Journal of the... Sep 2022Instrumentation for flow cytometry and sorting is designed around the assumption that samples are single-cell suspensions. However, with few exceptions, higher plants... (Review)
Review
Instrumentation for flow cytometry and sorting is designed around the assumption that samples are single-cell suspensions. However, with few exceptions, higher plants comprise complex multicellular tissues and organs, in which the individual cells are held together by shared cell walls. Single-cell suspensions can be obtained through digestion of the cells walls and release of the so-called protoplasts (plants without their cell wall). Here we describe best practices for protoplast preparation, and for analysis through flow cytometry and cell sorting. Finally, the numerous downstream applications involving sorted protoplasts are discussed.
Topics: Cell Separation; Flow Cytometry; Protoplasts; Suspensions
PubMed: 34028996
DOI: 10.1002/cyto.a.24461 -
The International Journal of... Nov 2023Tablets are the most widely available dosage form for the treatment of TB; however, adult tablets fail to meet the needs of young children who cannot swallow these...
Tablets are the most widely available dosage form for the treatment of TB; however, adult tablets fail to meet the needs of young children who cannot swallow these tablets or require dose titration. We tested a new, simple device (XTEMP-R) and the methodology for converting tablets of TB drugs into a homogeneous suspension for home use by children and caregivers. XTEMP-R is a new device used for converting tablets into liquid preparations. Four TB drugs - pretomanid, delamanid, clofazimine and bedaquiline - were dispersed in the device utilizing water and simple syrup. The reproducibility of accurately delivering aliquots from the suspension upon preparation and upon redispersion after storing for 2 days was studied. Suspensions of each of the drugs tested were easily prepared in about 10 min and were visually uniform in consistency. Dosages in 2 and 5 mL were assessed in suspension, and those in 5 mL tested upon redispersion after 2 days. The observed range for these dosages spanned from 94.6% to 101.1% of the theoretical concentration for the suspensions under examination. The cleaned device had no detectable residual drug. XTEMP-R can be used at home by caregivers to prepare doses of suspensions accurately for children and patients who cannot swallow tablets.
Topics: Child; Adult; Humans; Child, Preschool; Reproducibility of Results; Tuberculosis; Tablets; Suspensions; Drug Stability
PubMed: 37880886
DOI: 10.5588/ijtld.23.0165 -
Environmental Science & Technology Nov 2022The rapid development of nanomaterials (NMs) and the emergence of new multicomponent NMs will inevitably lead to simultaneous exposure of organisms to multiple... (Review)
Review
The rapid development of nanomaterials (NMs) and the emergence of new multicomponent NMs will inevitably lead to simultaneous exposure of organisms to multiple engineered nanoparticles (ENPs) at varying exposure levels. Understanding the joint impacts of multiple ENPs and predicting the toxicity of mixtures of ENPs are therefore evidently of importance. We reviewed the toxicity of mixtures of ENPs to a variety of different species, covering algae, bacteria, daphnia, fish, fungi, insects, and plants. Most studies used the independent-action (IA)-based model to assess the type of joint effects. Using co-occurrence networks, it was revealed that 53% of the cases with specific joint response showed antagonistic, 25% synergistic, and 22% additive effects. The combination of nCuO and nZnO exhibited the strongest interactions in each type of joint interaction. Compared with other species, plants exposed to multiple ENPs were more likely to experience antagonistic effects. The main factors influencing the joint response type of the mixtures were (1) the chemical composition of individual components in mixtures, (2) the stability of suspensions of mixed ENPs, (3) the type and trophic level of the individual organisms tested, (4) the biological level of organization (population, communities, ecosystems), (5) the exposure concentrations and time, (6) the endpoint of toxicity, and (7) the abiotic field conditions (e.g., pH, ionic strength, natural organic matter). This knowledge is critical in developing efficient strategies for the assessment of the hazards induced by combined exposure to multiple ENPs in complex environments. In addition, this knowledge of the joint effects of multiple ENPs assists in the effective prediction of hybrid NMs.
Topics: Animals; Ecosystem; Nanoparticles; Nanostructures; Daphnia; Suspensions; Plants
PubMed: 36196869
DOI: 10.1021/acs.est.2c03333 -
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