Magnesium-bismuth films

The surface-phase layers will difier in character depending on the stractures of metal and oxide. On certain metals (zinc, cadmium, magnesium, etc.), loose, highly porous layers are formed which can attain appreciable thicknesses. On other metals (aluminum, bismuth, titanium, etc.), compact layers with low or zero porosity are formed which are no thicker than 1 pm. In a number of cases (e.g., on iron), compact films are formed wfiicfi fiave a distorted lattice, owing to the influence of substrate metal stracture and of the effect of chemical surface forces. The physicochemical and thermodynamic parameters of such films differ from tfiose of ordinary bulk oxides. Because of the internal stresses in the distorted lattice, such films are stable only when their thickness is insignificant (e.g., up to 3 to 5 nm). 

Neither 10 mL of Maalox (aluminium/magnesium hydroxide) nor 10 g of Solugastril (aluminium hydroxide with calcium carbonate) had any effect on the pharmacokinetics of a 4-mg lomoxicam film-coated tablet in 18 healthy fasted subjects. A later study similarly found no changes in the absorption or pharmacokinetics of a lomoxicam film-coated tablet given with bismuth chelate (tripotassium dicitratobismuthate) 120 mg twice daily. There would seem to be no reason for avoiding concurrent use. 

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