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Question

Posted on: January 22 2018

Can fenytoin 10% creme also be made with buffered Cetomacrogol cream TMF?

R/phenytoin 10%, in basic creme ad 60g On your questionbox there was a solution for this preparation, namely: Nipagine 25mg, Nipasol 15mg, nalauryl sulfate 1g, propylene glycol 12g, cetyl alcohol 25g, Vaseline 25g and water up to 100g. Can this also be made with buffered Cetomacrogol cream TMF? It looks for a well-lubricating cream. Furthermore, we wonder if phenytoin can be used for this?

Answer

The specified formula is the one that we thought is closest to the composition of the base cream, which is used in the US. In principle, you should use Phenytoin, not available in Belgiê. When you use the buffered Cetomacrogol cream TMF, a portion of the Nafenytoîne will be converted into phenytoin. Of course, the buffer is unable to convert the full 10%. This could be obtained by adding diluted acetic acid to pH = 6.  

The buffered Cetomacrogol cream will not be less consistent like this, which we quote. You can use the Cetomacrogol cream of the Formularium Dutch pharmacists (see TMF). This used a liquid wax. She is less consistent and the liquid was a absorption promoter. You can add the TMF buffer to this formula or simply set the pH directly with diluted acetic acid to 6   after adding naphenytoin.