Disposable devices for the dispensing of oral drops. Study of photoprotectiveness and compatibility

Amber-coloured syringes designed for the distribution of unit-doses of oral drops were studied for the efficiency of the photoprotectiveness and the possible binding of eleven phenothiazine neuroleptics: alimemazine, chlorpromazine, cyamemazine, fluphenazine, levomepromazine, periciazine, pipotiazine, prochlorperazine, thioproperazine, thioridazine, and trifluoperazine, all very easily oxidized in solution in daylight. Spectrofluorimetry made it possible, in one operation, to determine the remaining concentrations of drugs after storage and to verify the absence of photo-oxidation. The storage was performed up to 13 days at 25 +/- 3 degrees C and without any precaution from daylight. All the drugs studied were stable and none bound on the syringes. However, the stability appeared to be due to the antioxidants in the drug preparations, and not to the coloured material, since oral drops were also stable in uncoloured syringes designed for injection. Nevertheless, the amber-coloured syringes efficiently protect the active principles in pure aqueous solutions, without preservative, and thus this physical protection reinforces the chemical one of the galenical formulation.