Question
Posted on: January 20 2015Do I need to replace the non-ionogenic Cetomacrogel cream with hydrophilic anionic cream in the following regulation? Or by another non-ionogenic cream genre Ung aquosum non ionicus NF5?
Answer
Both Cetomacrogol cream TMF and non-ionogenic ointment (better cream) contain an emulsifier with a polyethylene glycol chain. So both are incompatible with resorcinol. This means Dar we are designated on another cream base. Logically, we could use a cetrimlde cream. But this is not common. Then the hydrophilic anionic cream with which we see an incompatibility with lidocaïneH +. As a major exception, Lidocaine HCl is compatible with anionic emulsifiers and polymers. Had this been the case now as with procaïneHCl then we can solve this incompatibility by neutralizing Procaine H + with a little base like Triethanolamine. Or nabenzate had to be replaced by Nipagine-Nipasol seems not necessary to me. It is difficult to estimate the pH of the aqueous solution on a theorertic basis.