Magnesium oxide is a basic compound and as such can react with acidic
compounds in the solid state to form salts such as Mg(ibuprofen)2 or degrade
alkaline-labile drugs.Adsorption of various drugs onto magnesium oxide has been
reported, such as antihistamines, antibiotics (especially
tetracyclines),salicylates, atropine sulfate,hyoscyamine hydrobromide,
paracetamol, chloroquine; and anthranilic acid derivatives have been reported to
adsorb onto the surface of magnesium oxide. Magnesium oxide can also complex
with polymers, e.g. Eudragit RS, to retard drug release and can interact in the
solid state with phenobarbitone sodium.
Magnesium oxide can also reduce the bioavailability of phenytoin,trichlormethiazide,and antiarrhythmics.The presence of magnesium oxide can also have a negative impact on the solid-state chemical stability of drugs, such as diazepam.Magnesium oxide has been used as a stabilizer for omeprazole due to its strong waterproofing effect.