抄録
Polystyrene sulfonate drugs (PSS) are likely to adsorb coadministered drugs through ionic and hydrophobic interactions because of their chemical structures. Nine drugs frequently dispensed at our 3 pharmacies to administer with PSS concurrently were selected and examined for their adsorption in vitro to Kalimate® powder in pH 6.8.
Cationic drugs in the solution, amlodipine besylate and dilazep hydrochloride hydrate were adsorbed almost totally, while anionic drugs, aspirin, furosemide and losartan potassium were only adsorbed in 0-15%. Non-ionic drugs, allopurinol, nifedipine and prednisolone were adsorbed to different extents, 9, 59 and 84%, respectively in proportion to their hydrophobicity (XLogP3). These data clearly indicate that cationic drugs and highly hydrophobic non-ionic drugs are susceptible to be adsorbed by PSS.
The dissolution test of Adalat® L at pH 6.8, pH 4.5 and pH 1.2 in the presence of Argamate® Jelly showed that release of nifedipine was apparently depressed markedly at any pH.
We propose that a description directing attention to the interaction with a wide range of drugs is added in the package inserts of PSS to avoid the occurrence of drug interactions.
