Antacids incorporation in immediate release tablets failed to improve the stability of omeprazole in acidic media

Abstract

Background: The stability of omeprazole (OMZ) decreases in acidic medium. In this
investigation, attempts have been made to develop oral tablet containing antacids/buffers
to increase the pH of dissolution media for certain time. Materials and Methods: Tablet
formulations were prepared by the direct compression technique. For the selection
of superdisintegrant, Croscarmellose sodium, used initially was replaced with other
superdisintegrants. The prepared tablets were evaluated for hardness, weight variation,
thickness, friability, drug content, disintegration time and in vitro drug release studies.
During the in vitro drug release studies, the pH of dissolution media was measured.
Results and Discussion: All batches showed very short disintegration time, within
0.5-2 min except F1 and S5. Batch F7 was able to provide the immediate drug release.
The study showed that the incorporation of antacid improved the pH of dissolution
media, but failed to maintain it. Even though the high quantities of antacids were
incorporated; the stability of drug in media was not improved. Other superdisintegrants
did not show any significant changes in drug release or disintegration time. Bath F7
was stable for the period of 6 months at 40o
C / 75 %RH. Conclusions: Incorporation
of higher quantities of antacids failed to retain the stability of OMZ in acidic media.