Comparison of in vitro surface properties of clove oil-phospholipid suspensions with those of ALEC, Exosurf and Survanta.

Dipalmitoyl phosphatidylcholine, the main component of lung surfactant is ineffective as a replacement surfactant due to its poor adsorption. We studied clove oil as a possible additive for improving the surface activity of protein-free phospholipid suspensions. We added low doses of clove oil, to phospholipid suspensions and studied the surface properties by in vitro analysis using a pulsating bubble surfactometer and a Wilhelmy balance. Survanta, ALEC and Exosurf were used as controls for comparison. The test surfactants, which were phospholipid-oil suspensions at 1% concentration, in buffer containing either 2 or 5 mM calcium, were pulsated at 40 cpm in a pulsating bubble surfactometer. The phospholipids studied were dipalmitoyl phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), binary mixtures of PC:PE (2:3) and PC:PG (2:3). The addition of clove oil (CO) to each of the above phospholipids was in the ratio of nine parts of phospholipid to one part of oil. The presence of CO caused a significant improvement in the adsorption and minimum surface tension of all the phospholipid suspensions studied. The mixtures PC with CO, both in the presence of 2 and 5 mM calcium, and PCPE with CO at 2 mM calcium concentration had surface properties significantly better than those of ALEC and Exosurf and equivalent to those of Survanta. The addition of clove oil helps improve the surface properties of phospholipids.