[Jorginho]

Hello I wish to formulate my own anticataract eyedrops.

Three things are important:

1) acidity (alkalinity): the drops needs to be between 6,8 and 7,4. As
the basic components combined most likely be slightly acidic, I will
use Borate to counter this (also a preservative used in eyedrops)

2) isotonicity (although eyedrops can me hypertonic a bit).
usually you use NaCl or Borate for this. NaCL in 0,9% Wt %.
Borate in a 2%Wt %.

3) sterility. You do not want an eyeinfection.


So 1 is covered easily, I have a calibrated pH meter 0,01 resolution.

2) I do not think that just any solution with 0,9% naCL in it will therefor
be isotonic. The other components all have their influence. So I can see myself
ending up with the right pH value, but the wrong osmocity.Any thought how to do this?
Titration? I also have Boric acid to counter Borate if necessary?
Can anyone do a calculation on istonicity for me when I give the exact formulation?

3) All ingredients have a melting and (therefor) boiling point a 105 C or higher.
Of course sterilised water is at 100,0 C. If this is so, can I put a 10-15 ml HDPE
dropper bottle in boiling water, so the solution inside becomes sterile without
getting some reaction or change in the solution?? Prior to boiling the solution
will be filtered through a 0,22 micron filter so very little germs etc will be
in it anyways.

I think 1 + 2 I can figure out with their molecular weights, but 3 I am unsure of.

Any thought.

Thanks in advance!

[Arkcon]

Kindly trouble yourself to read the Forum rules.  We don't give people specific instructions for self medication on the Forum, for liability reasons.  I see nothing in your formulation that is remotely a medicine, so I don't see how this will help.  You seem to understand the basics of formulation, but you are in no way enough of an expert to prepare things for yourself.  So I'm going to wind up by telling you to forget this plan of yours.