Stability of aminophylline

Abstract

The stability of aminophyline was studied in the presence of four tablet excipients (callu1ose starh, glucose and lactose) and nine intravenous fluids (water for injection, dextrose. 10% normal saline, dextrose normal saline 5%, Ringer lactate, Ringer, aminoplasmal 5%, lipofundin 10%, total parenteral nutrition solution TPNS). Ten percent mixtures of the powder drug with the excipients were kept at 5 degrees C, room temperature (27+/-3 degrees C), 45 degrees C and in direct sunlight for 30 days. The degradation of the drug increases with increase in temperature and on exposure to sunlight. The degradation is particularly intense in the presence of glucose and lactose and change in colour from white to yellow occurs in such mixtures. At 45 degrees C and in sunlight both pure drug and its mixtures change colour during the storage period. In intravenous fluids, the drug (1 g/L) is stable and physically compatible for 2 days at 5 degrees C, 27+/-3 degrees C and 45 degrees C except in lipofundin 10% and TPNS where the drug is stable for only 12 hours at 45 degrees C. Yellow tinge appears in the admixtures containing dextrose after 2 days at room temperature and at 45 degrees C.