STABILITY OF ATENOLOL IN AN EXTEMPORANEOUSLY COMPOUNDED ORAL LIQUID

The stability of atenolol in an oral liquid stored for 40 days under v arious conditions was studied. A liquid preparation of atenolol 2 mg/m L was prepared by triturating 50-mg atenolol tablets with a commercial ly available oral diluent. Twelve 30-mL portions in vials were prepare d. Three vials were refrigerated (5 degrees C) and shaken immediately before analysis, three were stored at room temperature (25 degrees C) and shaken, three were refrigerated and not shaken, and three were sto red at room temperature and not shaken. One sample from each vial was assayed in duplicate on days 0, 15, 30, and 40 by stability-indicating high-performance liquid chromatography. The concentration of atenolol remained above 90% of the original concentration in each vial under e ach of the four sets of conditions. Microbial growth occurred in a few cultured samples, and pH changed minimally. Atenolol 2 mg/mL in an or al liquid was stable for up to 40 days when stored at 5 or 25 degrees C and shaken or at 5 or 25 degrees C and not shaken.