Phenergan Cream is out of the trade. A patient asks me to make the cream. Is it possible to process Promethazine. HCl in e.g. Cetomacrogol cream?

Your proposal is partly correct in that you avoid the incompatibility of cation-anion with cetomacrogol cream, which you would have for example with Beelerbasis. But in dissolved form Promethazine is little stable. Therefore, we prefer to strike it down in situ this is during the preparation of the cream. To achieve this, an Alcalisch reacting cream base OIF BV The Stearaatcreme FN 5, which is described in the Galenic formulary P 169, is used. The same booklet gives on page 170 the composition of a cremor promethazini.

But given that stearic acid is no longer available we make use of 8 D cetostearyl alcohol and 2 D Cetomacrogol 1000 (self-emulsifying cetomacrogolwas). This then gives