STABILITY OF A LESS-PAINFUL INTRAVENOUS EMULSION OF CLARITHROMYCIN

The chemical stability of a less-painful ready-to-use o/w emulsion for intravenous (i.v.) delivery of clarithromycin was investigated. The f ormulation contained 0.5% w/v drug, 2% w/v soybean oil, 5% w/v egg pho sphatide, 0.6% w/v oleic acid, 0.3% hexanoic acid and 2.5% w/v glyceri n in water. The change in the initial pH of emulsion (range: 6.5-8.0) did not significantly influence drug stability over a period of 30 day s at 5 and 30 degrees C. The increase in the initial pH of emulsion as well as its storage temperature gradually decreased the final pH over time. The emulsion prepared at pH 7.5 demonstrated a constant drop in pH over 9 months at 30 degrees C at the rate of about 0.002 units dro p in pH per day; however, it did not demonstrate significant loss of d rug. Actual as well as projections using accelerated stability studies indicated the shelf-life (i.e., time to retain 90% of the label claim , t(90%)) of the emulsion formulation, at 25 degrees C, to be greater than or equal to 21 months. Overall, the results suggest that the deve lopment of a less-painful ready-to-use o/w emulsion of clarithromycin is feasible.