Improvement of Bleached Shellac as Enteric Coating by Composite Formation

2021 ◽  
Vol 22 (7) ◽  
Author(s):  
Manee Luangtana-anan ◽  
Suthep Saengsod ◽  
Sontaya Limmatvapirat
2003 ◽  
Vol 772 ◽  
Author(s):  
T. Seeger ◽  
G. de la Fuente ◽  
W.K. Maser ◽  
A.M. Benito ◽  
A. Righi ◽  
...  

AbstractCarbon nanotubes (CNT) are interesting candidates for the reinforcement in robust composites and for conducting fillers in polymers due to their fascinating electronic and mechanical properties. For the first time, we report the incorporation of multi walled carbon nanotubes (MWNTs) into silica-glass surfaces by means of partial surface-melting caused by a continuous wave Nd:YAG laser. MWNTs were detected being well incorporated in the silica-surface. The composites are characterized using scanning electron microscopy (SEM) and Raman-spectroscopy. A model for the composite-formation is proposed based on heatabsorption by MWNTs and a partial melting of the silica-surface.


2019 ◽  
Vol 13 (2) ◽  
pp. 83-90 ◽  
Author(s):  
Hetal Patel ◽  
Mukesh Gohel

Enteric coated dosage form bypasses the stomach and releases the drug into the small intestine. Advantages of enteric coated pellets in comparison with enteric coated tablets are a) Pellets provide rapid onset of action and faster drug release due to the smaller size than tablets and b) Pellets exhibit less residence time of acid-labile drugs in the stomach compared to tablets. Dosage form coat can be damaged by longer resistance time in the stomach. The present review summarizes the current state of enteric coated pellets where core pellets are prepared by extrusion-spheronization technique and the enteric coating is applied in a fluidized bed processor. Two approaches are involved in the preparation of core pellets. In the first approach, a mixture of drug and excipient(s)/co-processed excipient is passed through extruders to prepare core pellets. In the second approach, excipient core pellets are prepared by extrusion technique and the drug is layered onto it before the enteric coating. The excipients present in the core pellets decide immediate or extended release of drug in the intestine. The coprocessed excipient pellets provide less batch variability and provide a platform for layering of many drugs before enteric coating. Some patents included enteric coating pellets [CN105456223 (A), CN105596310 (A), CN105616371 (A), CN105663095 (A), CN101611766B, CN106511862 (A), CN106668018 (A), CN106727381 (A), CN106924222 (A), TW200624127 (A), US 2017/0165248A1, US 2017/0224720A1] are discussed.


Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1406 ◽  
Author(s):  
Yasmin Ranjous ◽  
Géza Regdon ◽  
Klára Pintye-Hódi ◽  
Tamás Varga ◽  
Imre Szenti ◽  
...  

Recently, there has been an increasing interest in the application of nanotubular structures for drug delivery. There are several promising results with carbon nanotubes; however, in light of some toxicity issues, the search for alternative materials has come into focus. The objective of the present study was to investigate the influence of the applied solvent on the composite formation of titanate nanotubes (TNTs) with various drugs in order to improve their pharmacokinetics, such as solubility, stability, and bioavailability. Composites were formed by the dissolution of atenolol (ATN) and hydrochlorothiazide (HCT) in ethanol, methanol, 0.01 M hydrochloric acid or in ethanol, 1M sodium hydroxide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), respectively, and then they were mixed with a suspension of TNTs under sonication for 30 min and vacuum-dried for 24 h. The structural properties of composites were characterized by SEM, TEM, FT-IR, differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, and optical contact angle (OCA) measurements. Drug release was determined from the fast disintegrating tablets using a dissolution tester coupled with a UV–Vis spectrometer. The results revealed that not only the good solubility of the drug in the applied solvent, but also the high volatility of the solvent, is necessary for an optimal composite-formation process.


2020 ◽  
Vol 5 (1) ◽  
pp. 18
Author(s):  
Simon Evertz ◽  
Stephan Prünte ◽  
Lena Patterer ◽  
Amalraj Marshal ◽  
Damian M. Holzapfel ◽  
...  

Due to their unique property combination of high strength and toughness, metallic glasses are promising materials for structural applications. As the behaviour of metallic glasses depends on the electronic structure which in turn is defined by chemical composition, we systematically investigate the influence of B concentration on glass transition, topology, magnetism, and bonding for B concentrations x = 2 to 92 at.% in the (Co6.8±3.9Ta)100−xBx system. From an electronic structure and coordination point of view, the B concentration range is divided into three regions: Below 39 ± 5 at.% B, the material is a metallic glass due to the dominance of metallic bonds. Above 69 ± 6 at.%, the presence of an icosahedra-like B network is observed. As the B concentration is increased above 39 ± 5 at.%, the B network evolves while the metallic coordination of the material decreases until the B concentration of 67 ± 5 at.% is reached. Hence, a composite is formed. It is evident that, based on the B concentration, the ratio of metallic bonding to icosahedral bonding in the composite can be controlled. It is proposed that, by tuning the coordination in the composite region, glassy materials with defined plasticity and processability can be designed.


2020 ◽  
Vol 13 (18) ◽  
Author(s):  
Peng Zhang ◽  
Yajing Pan ◽  
Zhaocheng Yu ◽  
Xiaoming Guan ◽  
Gang Wang ◽  
...  

2021 ◽  
pp. 1-14
Author(s):  
M. Reza Azarpazhooh ◽  
Chrysi Bogiatzi ◽  
J. David Spence

Combining available therapies has the potential to reduce the risk of stroke by 80% or more. A comprehensive review of all aspects of stroke prevention would be very lengthy; in this narrative review, we focus on some aspects of stroke prevention that are little-known and/or neglected. These include the following: (1) implementation of a Mediterranean diet; (2) B vitamins to lower homocysteine; (3) coordinated approaches to smoking cessation; (4) intensive lipid-lowering therapy; (5) lipid lowering in the elderly; (6) physiologically individualized therapy for hypertension based on renin/aldosterone phenotyping; (7) avoiding excessive blood pressure reduction in patients with stiff arteries; (8) treatment of insulin resistance with pioglitazone in stroke patients with prediabetes and diabetes; (9) impaired activation of clopidogrel in patients with variants of CYP2C19; (10) aspirin pseudoresistance due to enteric coating; (11) rationale for anticoagulation in patients with embolic stroke of unknown source; (12) pharmacologic properties of direct-acting oral anticoagulants that should be considered when choosing among them; (13) the identification of which patients with asymptomatic carotid stenosis are at a high enough risk to benefit from carotid endarterectomy or stenting; and (14) the importance of age in choosing between endarterectomy and stenting. Stroke prevention could be improved by better recognition of these issues and by implementation of the principles derived from them.


1994 ◽  
Vol 20 (6) ◽  
pp. 1021-1034 ◽  
Author(s):  
Y. Kane ◽  
J. Rambaud ◽  
H. Maillols ◽  
J. P. Laget ◽  
D. Gaudy ◽  
...  

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