Famotidine is a member of H2-receptor antagonist drug, which pharmacological action
primarily involves antagonism of the action of histamine at its H2-receptors. The incompatibility
between famotidine and some commonly used tablet excipients was studied. The investigation
was made on Avicel PH 105, Emcocel 90, starch 1500 (Sta-Rx 1500), Emdex, sorbitol,
mannitol, cross linked sodium carboxymethylcellulose (Ac-Di-sol), PEG6000,
hydroxyethylcellulose (HEC) (natrosol) and saccharin sodium. The investigation is made by
DSC, IR and X-ray diffraction analysis. The DSC analysis indicated that there was no
interaction between famotidine with Emcocel 90, Avicel PH 105, starch 1500, Ac-Di-sol,
mannitol, HEC (natrosol) and saccharin sodium. On the other hand DSC indicated an
incompatibility between famotidine and sorbitol, Emdex and PEG6000. The study of IR
indicated the interaction between famotidine and PEG6000. X-ray diffraction study was carried
out on excipients that showed possible interaction with famotidine during the DSC
investigations. Only interaction between famotidine, Emdex and PEG6000 was confirmed.