Carbomer 940 gel liquified

I made gel for methyl ester in 40% ethanol using carbomer 940, ph 7.2
After 1 month the gel turn liquid. 
No significant ph change observed. 
What could be the reson and solution. 
Buffer?

Also i tried to change the gelling agebt and used hpmc but i gives dryout layer. 

Any suggestions for the carbomer. 
And if i want to change the geeling agent, any suggestions 
Thanks

Comments

  • chemicalmattchemicalmatt Member, Professional Chemist
    @omer are you referring to soy methyl esters? Depending on how much you used, and how much %water, that likely dissolved/disrupted the cross-links in the Carbopol. Try using Acrylates Copolymer or another acrylic copolymer compatible with ethanol and see what happens. 
  • omeromer Member
    @chemicalmatt
    I am referring to conventional methyl ester. 
    I used cellulose ether based gelling agent but i give bad after application effect.
    I don't have many gelling agents choices. 
    So i am looking to solve the problem if possible. 
    What i am thinking about is:
    Use buffer ph 6_7(unfortunately carbomer 940 electrolytes senstive) 
    Looking for suggestions 
  • Try carbopol ultrez 21 @ 0.3%+0.1 AMP95 or TEA
    AND YOU WILL BE SATISFIED 
  • omeromer Member
    Thanks Androus, 
    Will try as soon as get it
  • omer said:
    @chemicalmatt
    I am referring to conventional methyl ester. 
    I used cellulose ether based gelling agent but i give bad after application effect.
    I don't have many gelling agents choices. 
    So i am looking to solve the problem if possible. 
    What i am thinking about is:
    Use buffer ph 6_7(unfortunately carbomer 940 electrolytes senstive) 
    Looking for suggestions 
    Which conventional methyl ester? 
    How are you neutralising the carbomer? It should be controllable to around pH 6-7 fairly easily with TEA at 40% ethanol.
    I agree that it is electrolytes sensitive, which is not ideal, but it is manageable.
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