So the guy I bought 5 microns from off ebay says the only .20um he has are for oil based solutions only and won't work for water, he said he would look around to see if he had and .20s meant for water based solution and I told him if he can't find any to give me the .45s. I have never heard of this, are there different types of microns for different solutions and will an "oil .20" really not work with water? It's just a filter, what could be the difference?
How much of a difference is there between .45s and .20s?
There are many different membrane types. The there are 3 main types that are suitible for filtering water soluble drugs:
1. PES (Polyethersulfone) ~ Best
2. PVDF (Polyvinylidene difluoride) ~ Better
3. Nylon ~ Good
All three of these membrane types are HYDROPHILIC
Sterile 0.2 Micron filters are the most suitible, although I have some Sterile 0.1 Micron filters that work very well but tend to be more expensive.
If filtering pills, ALWAYS prefilter through tightly rolled cotton first to avoid clogging the Wheel filter. I find the cotton packed syringe method to be the best.