A Simple Method to Determine Cytotoxicity of Water-Soluble Organic Compounds and Solid Particles from Biomass Combustion in Lung Cells in Vitro

2019 ◽  
Vol 53 (7) ◽  
pp. 3959-3968 ◽  
Author(s):  
Peter Zotter ◽  
Stéphane Richard ◽  
Marcel Egli ◽  
Barbara Rothen-Rutishauser ◽  
Thomas Nussbaumer
Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1126
Author(s):  
Dipy M. Vasa ◽  
Zainab Bakri ◽  
Maureen D. Donovan ◽  
Lauren A. O’Donnell ◽  
Peter L. D. Wildfong

Ribavirin is a water-soluble antiviral compound which, owing to its inability to cross the blood–brain barrier, has limited effectiveness in treating viruses affecting the central nervous system. Direct nose-to-brain delivery was investigated for ribavirin in combination with poloxamer 188, an excipient known to enhance the absorption of drug compounds administered intranasally. Composite solid microparticles suitable for intranasal insufflation were prepared by suspending fine crystals of ribavirin in a matrix of poloxamer 188, which were cryogenically milled and characterized to ensure that ribavirin remained stable throughout preparation. In vitro diffusion of ribavirin across a semi-permeable regenerated cellulose membrane showed comparable cumulative drug release after 180 min from both fine solid particles (<20 µm) and 1:1 ribavirin:poloxamer microparticles (d50 = 20 µm); however, the initial release from polymer microparticles was slower, owing to gel formation on the membrane surface. When solid ribavirin was directly deposited on excised olfactory mucosa, either as fine drug particles or 1:1 ribavirin:poloxamer microparticles, permeation was significantly increased from microparticles containing poloxamer 188, suggesting additional interactions between the polymer and olfactory mucosa. These data indicate that for highly water-soluble drugs such as ribavirin or drugs subject to efflux by the nasal mucosa, a formulation of poloxmer-containing microparticles can enhance permeability across the olfactory epithelium and may improve direct nose-to-brain transport.


1973 ◽  
Vol 30 (01) ◽  
pp. 138-147 ◽  
Author(s):  
Christopher R. Muirhead

SummaryThe filter loop technique which measures platelet aggregation in vivo in the flowing-blood of the rat was compared to the optical density technique of Born which is carried out in vitro with platelet rich plasma. Using these two experimental models the effect on platelet aggregation of three known inhibitors sulfinpyrazone, dipyridamole and prostaglandin E1, and a novel compound 5-oxo-l-cyclopentene-l-heptanoic acid (AY-16, 804) was determined.The effects on platelet aggregation of the known inhibitors were consistent with information in the literature. Prostaglandin E1 was the most potent inhibitor in both techniques; sulfinpyrazone inhibited aggregation in both models but was less potent than prostaglandin E1. AY-16, 804 exhibited activity in vitro and in vivo similar to that of sulfinpyrazone. Dipyridamole did not inhibit platelet aggregation in vivo and did not inhibit aggregation in vitro in concentrations at which it remained soluble.The filter loop technique is a suitable model for measuring platelet aggregation in the flowing blood of the rat. It is a relatively simple method of determining aggregation and easily adapted to other species.


Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website


Author(s):  
Lê Thanh Long ◽  
Nguyễn Văn Toản ◽  
Nguyễn Văn Huế ◽  
Trang Sĩ Trung ◽  
Vũ Ngọc Bội

Chủng D1 phân lập từ các mẫu chuối có vết bệnh thán thư điển hình được sử dụng để nghiên cứu khả năng kháng nấm của chitosan hoà tan trong nước (Water-soluble chitosan_WSC) ở điều kiện in vitro. Kết quả phân tích trình tự gen mã hoá 28S rRNA của chủng D1 cho thấy tương đồng trình tự cao với các trình tự tương ứng của loài Colletotrichum musae và được ký hiệu là Colletotrichum musae D1. Kết quả các thí nghiệm đều cho thấy C. musae D1 rất nhạy cảm với WSC, hiệu lực ức chế tăng khi tăng nồng độ WSC xử lý ở điều kiện in vitro. Trên môi trường PDA, nồng độ 1,6% WSC ức chế hoàn toàn sự sinh trưởng của sợi nấm C. musae D1, nồng độ ức chế 50% (PIRG50) và nồng độ ức chế tối thiểu 90% (MIC90) tương ứng với nồng độ WSC 0,28% và 0,88%. Trong môi trường PDB, giá trị IC50 và MIC90 tương ứng là 0,11% và 0,43% và sự phát triển của sợi nấm C. musae D1 bị ức chế hoàn toàn ở nồng độ 0,8%. WSC không chỉ ức chế sự nảy mầm mà còn gây biến đổi bất thường bào tử nấm khi quan sát trên kính hiển vi.


Tellus B ◽  
2011 ◽  
Vol 63 (5) ◽  
Author(s):  
Puja Khare ◽  
B. P. Baruah ◽  
P. G. Rao

2011 ◽  
Vol 50 (06) ◽  
pp. 234-239 ◽  
Author(s):  
R. Guo ◽  
Y. Ma ◽  
R. Zhang ◽  
S. Liang ◽  
H. Shen ◽  
...  

Summary Aim: Angiogenesis plays a critical role in tumour formation and metastasis. Suitable radiolabeled angiogenesis inhibitor can be used for noninvasive imaging of angiogenesis and radionuclide therapy. Here we prepare rhenium-188 labeled recombinant human plasminogen kringle5 (188Re-rhk5) in a convenient manner than evaluate its properties in A549 lung adenocarcinoma. Methods: 188Rerhk5 was obtained by conjugating His group at the C end of rhk5 with fac- [188Re(H2O)3(CO)3]+. Chelating efficiency of fac-[188Re(H2O)3(CO)3]+ and radiolabeling efficiency of 188Re-rhk5 were measured by radio thin-layer chromatography (RTLC). In vitro stability of 188Re-rhk5 was determined in human serum at 37°C and analyzed by RTLC. Competition test was also performed to verify the specificity of binding. A biodistribution study was carried out in nude mice bearing A549 lung adenocarcinoma. Results: 188Rerhk5 was obtained with a radiolabel efficiency of 66.1%, the radiochemical purity (RCP) can marreach 95.2% after purification. 188Re-rhk5 showed high stability in human serum, the RCP was more than 80% even 12 h after incubation. Competition test showed a high binding specificity. Furthermore, this radio-complex was excreted mainly through kidneys and showed specific tumour uptake in mice bearing A549 tumours. Conclusion: 188Re-rhk5 was prepared by a simple method. Preliminary biodistribution results showed its potential as an agent for possible tumour imaging, therapy and encouraged further investigation.


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