Question
Posted on: March 6 2013Oral spray prescribed by stomatologist: chlorhexidine 0.2% cetrimide 0.1% lidocaine 0.4%
In The national Formularium the formula is to be found of chlorhexedine oral spray. Chlorhexidine-Diacetate is used in this. Is there a reason why the digluconate salt is not used? In principle, the diacetate form is only soluble in alcohol, but it could be dissolved in the lemon spirit. Furthermore, Lidoca ï ne is prescribed, does this make any difference with Tetraca ï ne? Can problems arise with the acidity?
Answer
Tetraca ï NE is not synonymous with lidocaine! All "CA ï nes" are not equivalent. It makes no difference what chlorhexidine salt you use. Both are water soluble. However, there is an additional problem and this is the possible incompatibility of chlorhexidine with Cetrimide or cetrimoniumbromide. Chlorhexidine bromide is insoluble in water but given any incompatibility concentration is bound can form a precipitate or not. In any case, I would not use Lidoca ï neHCl but the base. I suspect that the pH will be too alcalisch for the stability of chlorhexidine and there will have to be acidified with diluted acetic acid to a pH = +/-4.5.