64 research outputs found
ПОЛУЧЕНИЕ ПОЛИМЕРНЫХ НАНОЧАСТИЦ С ИСПОЛЬЗОВАНИЕМ УЛЬТРАЗВУКОВОГО ДИСПЕРГИРОВАНИЯ В ПРОТОЧНОМ РЕЖИМЕ
The work is dedicated to the production of polymer suspensions using ultrasonic dispergation in a flow mode. An apparatus was designed on the basis of a Russian flow ultrasonicator. The applicability of this apparatus for obtaining aqueous dispersions of polymeric micro- and nanoparticles by means of one-step emulsification followed by solvent extraction / evaporation was demonstrated. The influence of the process parameters on the characteristics of the obtained suspensions was studied. The particle size distribution and the average size of the resulting particles were evaluated by using Delsa Nano S, Beckman Coulter laser analyzer (USA). The dependence of the average diameter of the suspension particles on the stabilizer concentration and on the change of the phases feed rate was shown. When polyvinyl alcohol was used as a stabilizer in the concentration range 0.5-2%, the average particle size was 30-400 nm. The feed rates of the aqueous and organic phases affect the nature of the particle size distribution.Работа посвящена получению полимерных суспензий с использованием ультразвукового диспергирования в проточном режиме. Разработана конструкция установки на базе проточного ультразвукового диспергатора российского производства. Показана применимость данной установки для получения водных дисперсий полимерных микро- и наночастиц методом одностадийного эмульгирования с последующей экстракцией/испарением растворителя. Изучено влияние параметров процесса диспергирования на характеристики получаемых суспензий. Средний размер полученных частиц и распределение частиц по размерам оценивали с помощью лазерного анализатора Delsa Nano S, Beckman Coulter (США). Показана зависимость среднего диаметра частиц суспензий от концентрации стабилизатора и изменения скорости подачи фаз. При использовании в качестве стабилизатора поливинилового спирта в диапазоне концентраций от 0.5 до 2% средний размер частиц составил от 30 до 400 нм, причем на характер распределения частиц по размерам влияют скорости подачи водной и органической фаз
A Polarised Population of Dynamic Microtubules Mediates Homeostatic Length Control in Animal Cells
An analysis of cells grown on micro-patterned lines, and of cells during zebrafish development, identifies a population of microtubules that align along the long axis of cells to mediate homeostatic length control
Recommended from our members
Impact of 3D cell culture on bone regeneration potential of mesenchymal stromal cells
As populations age across the world, osteoporosis and osteoporosis-related fractures are becoming the most prevalent degenerative bone diseases. More than 75 million patients suffer from osteoporosis in the US, the EU and Japan. Furthermore, it is anticipated that the number of patients affected by osteoporosis will increase by a third by 2050. Although conventional therapies including bisphosphonates, calcitonin and oestrogen-like drugs can be used to treat degenerative diseases, they are often associated with serious side effects including the development of oesophageal cancer, ocular inflammation, severe musculoskeletal pain, and osteonecrosis of the jaw.
The use of autologous mesenchymal stromal cells/mesenchymal stem cells (MSCs) is a possible alternative therapeutic approach to tackle osteoporosis while overcoming the limitations of traditional treatment options. However, osteoporosis can cause a decrease in the numbers of MSCs, induce their senescence, and lower their osteogenic differentiation potential.
Three-dimensional (3D) cell culture is an emerging technology that allows a more physiological expansion and differentiation of stem cells compared to cultivation on conventional flat systems.
This review will discuss current understanding of the effects of different 3D cell culture systems on proliferation, viability, osteogenic differentiation, as well as on the immunomodulatory and anti-inflammatory potential of MSCs
RATIONALE FOR THE SELECTION OF AUXILIARY COMPONENTS FOR THE NALTREXONE HYDROCHLORIDE NASAL SPRAY
The work is devoted to the development of nasal spray containing naltrexone hydrochloride. Naltrexone in doses of 3-5 mg/day acts on the opioid growth factor receptor (OGFr) and toll-like receptor 4 that makes it promising for use in the complex therapy of autoimmune diseases and conditions caused by impaired immunity. To prevent leakage of the drug from the nasal cavity, the thermosensitive poloxamer (Kolliphor® P 407) was introduced into its composition. The dynamic viscosity was studied of model samples in the temperature range of 7-37 °C. The rate of dialysis and the degree of release was investigated of naltrexone. Selected the optimal composition to create a comfortable to use drug «Naltrexone hydrochloride, nasal spray», 25 mg/ml
Microbiological Estimation of Nasal Spray Containing Naltrexone Hydrochloride
Introduction. In order to standardize the quality indicators during the expected shelf life of the developed drug naltrexone hydrochloride in the form of a nasal spray containing a high concentration of poloxamer and benzalkonium chloride as a preservative, a microbiological study was carried out. The possibility of using the membrane filtration method for testing prototypes recommended by the State Pharmacopoeia XIV.Aim. Study and selection of test conditions for the «microbiological purity» indicator of nasal spray samples containing naltrexone hydrochloride.Materials and methods. As an object of research, a naltrexone hydrochloride nasal spray was used. When analyzing the microbiological purity, the membrane filtration method recommended in the State Pharmacopoeia XIV.Results and discussion. As part of the study, it was found that the samples of the drug meet the requirements for a microbiological indicator for drugs of category 2. Testing the suitability of the method for samples of the dosage form showed that the antimicrobial effect of the drug was completely removed by washing the filter, which was proved by inoculation of indicator test microorganisms, the quantitative and qualitative nature of growth, which did not differ from the control without the drug.Conclusion. As a result of the studies carried out, the optimal test conditions for the «Microbiological purity» indicator for the nasal spray containing naltrexone hydrochloride were selected and substantiated
DEVELOPMENT AND STUDY OF THE CHARACTERISTICS OF OPHTHALMIC GELS BASED ON CARBOMER ACRYPOL 974P AND CADPOL 980
The work is devoted to the development of novel ophthalmic drug prolonged action in the treatment of cataract of different genesis, degeneration and corneal injury. The results showed the possibility of creating an ophthalmic gel based on carbomers with the addition taurine. The resulting preparation was studied on the basic parameters that demand for ophthalmic dosage forms
Use of Eu(DPM)3 to study the long-range spin-spin coupling of1H-1H and1H-14N via the PMR spectra
Quantitative Determination of Naltrexone Hydrochloride in a Nasal Spray by High-performance Liquid Chromatography
Introduction. Naltrexone, an antagonist of µ-opioid receptors, is promising for the treatment of various autoimmune and oncological diseases when used in doses of 1.5–5 mg/day. To date, there are no medications that provide such dosages of naltrexone.Aim. Development and validation of a method for the quantitative determination of naltrexone hydrochloride in a nasal spray by high performance liquid chromatography (HPLC).Materials and methods. As an object of research, a naltrexone hydrochloride nasal spray was used. The quantitative determination of naltrexone in the test sample was developed using a Dionex UltiMate 3000 high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a diode-matrix detector.Results and discussion. The possibility of using isocratic and gradient chromatographic modes for the quantitative determination of naltrexone hydrochloride in the nasal spray was studied. Based on these results, a new method of determination using the gradient mode is proposed, which allows minimizing the influence of the polymer component in the test sample on the analysis results.Conclusion. A new technique of high-performance liquid chromatography (HPLC) is proposed that allows identification and quantification of naltrexone hydrochloride in a nasal spray containing a high concentration of water-soluble heat-sensitive poloxamer as a thickener. The developed method was validated according to the parameters: correctness, precision, specificity, linearity
- …