currently am developing ophthalmic nano emulsion there is problem in dissolution method as of now am working dialysis method but its doesn't work it seems can any suggest the suitable method for dissolution.
One explanation may be your API dialysis rate is much slower than the rate it is released from the nano droplets of your formulation so dialysis is not the appropriate method. Drug solubility is also an important factor: is your drug highly lipophilic? or is it adsorbed in any plastic surface you can find in your dissolution system so you cant see it in the release medium....
Iam preparing ophthalmic nanoemulsion and am incorporating Steroidal anti inflamatory drug in to nanoemulsion.am unble to get the release profile perfectly
Dear Shanker , Products that include nano-“stuff” show some challenges in separating the free drug from the nanoparticles, nanocapsules etc. I guess that your question is due either to observing no release at all or observing a 100% (or close) release immediately, am I correct? What you mean by “unable to get the release profile perfectly” (could you please clarify)?
Am unable to get release profile perfectly.and how to get separate the oil phase and aqueous phase and micelles from nano emulsion.can you please comment on this topic too.
very much thanks for your patience on my questions.
Sir, Actually i have used dialysis membrane(100KD cellulose membrane)method for the dissolution of an nanoemulsion.
After 90 hours 99 % drug was released.actually i need less time for drug dissolution by dialysis method only.even i used 300KD also but the release proflie is similar like 100KD cellulose membrane.
But i didn't check the mass balance in receptor phase and donor phase
Dear Shanker, First of all we need to figure out (or at least have a good guess) on what the problem is! Is it release related (which means is a problem due to your formulation), is it the dissolution/release equipment methodology that is not suitable or is it an analytical issue. Sometimes these later 2 are related.
Nano particles I'm used to deal with are intended not to release the drug at the extracellular environment, but I don´t know what your goal is.
Secondly, the apparently release of ALL the drug from the nanocapsules may be due to (a) the drug actually being released or to (b) to the fact that both released drug and nanodroplets are crossing the dialysis membrane to the receptor phase.
Questions:
a) are you able to use a 10KD membrane and check if the results are similar?
b) are you able to quantify you oily phase in both the donor a receptor side?
c) are your nanocapsules stable at you release medium (I guess you did not disclose what was its composition).
As I don't disclose any details (I understand that you may not be allowed to do it) it is hard to give precise answers. Are you able to try some SPE (solid phase extraction) separations just to confirm the release/retention? This would although heavily depend on the nature of the surfactants/lipids used.
Please disclose as much info as you may. Finally, a kind reminder on the RG acknowledgment procedure: if you find some answers/contributions being valuable you should upvote them by clicking on the green up triangle. On the other side if you believe they are wrong, misleading,, etc, downvote them.
very much Thanks to you being patience on my questions,
As of now am using dissolution media as 0.05% SLS contains tear media buffers
am trying dialysis membrane method for drug diffusion to receptor medium i need to prove the release profile with in 5 hours
I have evaluated to all kinds of MW membranes(10KD-300KD) but the release is increasing more by increasing the MW.with MW release was less i mean it tooks more time to release from nanodroplets.
iam using dialysis membrane which can be validated but SPE is cost effective method it may not be validated i guess so.
Dissolution and broadly speaking any release testing have one of two purposes namely (a) to provide information on the in-vivo behaviour/performance or (b) as a quality control method to provide information on the impact of changes in the formula and/or manufacturing process (on purpose or accidental) on the product release kinetics.
In your particular case I’m not sure you have a problem with the release medium. Most probably it will reside somewhere in the sample preparation and/or analytical determination (just a guess). You state that increasing the dialysis pore size increases the release. I'm afraid that's not so! The release does not depends on the dialysis membrane. What changes is your perception of the release, most probably because you are quantifying also the nanocapsules that are able to cross the dialysis membrane together with the free drug.
If you are only concerned in getting the drug dissolved after 5 hours, all you just need to use a medium in which the drug is soluble! Maybe methanol or dichloromethane can do the job.
However I guess it’s not what you want and that was the reason for my previous questions. Try to figure out the reason why you are getting a low (I’m just guessing) release. Unfortunately, based on the available info, I can’t suggest any dissolution/release medium other than increasing the SLS amount (you may go up to 2% with proper, sound and solid justification). Try 0.5% or 1% and check if there are any changes (there are however drawbacks -some of them severe - in using surfactants in dissolution media).
i have used 0.5% -1% SLS concentration but the problem is it forms the micelles at above the concentration of 0.05% so that it will retard the release of nanoemulsion.
am working on ophthalmic formulations i cannot go for organic solvents as release media.