After preparing Eudragit RS 100-based nanocapsules, I want to separate them by using spin tubes. How can I determine MWCO and spin tube type?
Since the dialysis membrane consists of a spongy matrix of crosslinked polymers, the pore rating referred to as Molecular Weight Cut Off (MWCO), is an indirect measure of the retention performance. More precisely, the membrane MWCO is determined as the solute size that is retained by at least 90%. However, since a solute's permeability is also dependent upon molecular shape, degree of hydration, ionic charge and polarity, it is recommended to select a MWCO that is half the size of the MW of the species to be retained and at least 10 times larger than twice the size of the MW of the species intended to pass through.
Go to this link for example. This will give you some good idea. However, it may vary with company. Go through the list of items on the right hand sze such as pore size, membrane selection etc.
http://www.spectrumlabs.com/dialysis/SelectionGuide.html
Dear Dr. Milad Reda;
normally this is given by the company that produces it (if I understood well the question). Regards
Dear dr. Milad reda:
the first step is determine the size of the prepared Eudragit RS 100 based nano capsules by zeta/Nano sizer and you will get size distribution.
Now use molecular weight cut off molecular seives of the size required,(packed molecular seives or u can prepare it by different procedures), the larger will get entrapped and smaller size or required size can be collected by washing with required buffer.
Since the dialysis membrane consists of a spongy matrix of crosslinked polymers, the pore rating referred to as Molecular Weight Cut Off (MWCO), is an indirect measure of the retention performance. More precisely, the membrane MWCO is determined as the solute size that is retained by at least 90%. However, since a solute's permeability is also dependent upon molecular shape, degree of hydration, ionic charge and polarity, it is recommended to select a MWCO that is half the size of the MW of the species to be retained and at least 10 times larger than twice the size of the MW of the species intended to pass through.
Go to this link for example. This will give you some good idea. However, it may vary with company. Go through the list of items on the right hand sze such as pore size, membrane selection etc.
http://www.spectrumlabs.com/dialysis/SelectionGuide.html
Dear milad,
molecular cutoff can be determined by using various dialysis tubings ranging cutoff values from nano to micron. dialysis tubings with wide range of cutoff values are available in all major pharma based sites like sigma, fluka etc..
regards
cellulose acetate purchased from kemphasol, cas no : 9004-35-7. how to find the molecular weight cutoff
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