Retinoic acid 0.02 g, hydroquinc 1.6 g in Locoid Lipocreme ad 30g?

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LOCOID LIPOCREME 0.1% CREME: Cetostearyl alcohol – Macrogol 25 cetostearyl ether – Paraffin thin liquid – white petroleum jelly – propyl parahydroxybenzoate-Benzylacohol – anhydride Citric acid – anhydride sodium citrate – water   retinoic acid has an acid function, (see Chemical structure)  . It will react as acid with Nacitraat and make the pH more acidic. An acidic pH is detrimental to   the stability of hydrocortisone-17-butyrate   and Hydroquinone is known to be incompatible with Macrogols (PEG).       So there are two incompatibilities in this compound.   The Locoid Lipocrème should be replaced by Locoid ointment. It is added: 2% of a 2% concentrate of BHT in liquid paraffin (for Tretinoin)   and 0.5% ascorbic acid (for hydroquinone)   all powders well finrub. They do not solve.   You know the dangers of Tretinoin! You may not make this preparation and the necessary safety measures must   be taken. See TMF or my publication in the pharmaceutical journal for Belgium   P. p1 {margin: 0.0 px 0.0 px 0.0 px 0.0 px; font: 12.0 px Helvetica}