Dipalmitoylphosphatidylcholine (DPPC) is a phospholipid (and a lecithin) consisting of two C16 palmitic acid groups attached to a phosphatidylcholine head-group.

[2][3] Lung surfactant (LS) is a surface-active material produced by most air-breathing animals for the purpose of reducing the surface tension of the water layer where gas exchange occurs in the lungs, given that the movements due to inhalation and exhalation may cause damage if there is not enough energy to sustain alveolar structural integrity.

The monolayer formed by the LS on the interface is composed primarily of phospholipids (80%), in addition to proteins (12%) and neutral lipids (8%).

Among the phospholipids, the most prevalent one is phosphatidylcholine (PC, or lecithin) (70–85%), which in turn is the basis of a pool of similar diacylphophatidylcholines of which 50% is dipalmitoylphosphatidylcholine or DPPC.

[4] While DPPC itself already has the ability to reduce the surface tension of the alveolar liquid, the proteins and other lipids in the surfactant further facilitate the adsorption of oxygen into the air-liquid interface.

Its structure includes both a hydrophilic "head" and hydrophobic "tails", and it is this arrangement that makes it able to reduce the surface tension of the water layer.

The synthesis of the phospholipids contained in pulmonary surfactant takes place in the endoplasmic reticulum of type II pneumocytes.

The rest is formed by transacylation mechanisms that exchange palmitoyl groups for the unsaturated acyl chains of other related diacylphosphatidylcholines.

However, when the temperature is further increased to 55 °C, the DPPC bilayer structure changes significantly, which causes a decrease in the layer thickness.

This characteristic is due to its hydrophilic head, composed of the polar phosphatidylcholine group, and its hydrophobic tails, formed by two nonpolar palmitic acid (C16) chains.

This trait allows DPPC to easily and spontaneously form micelles, monolayers, bilayers and liposomes when it is in contact with a polar solvent.

The presence of some unsaturated phospholipids (such as dioleoylphosphatidylcholine [DOPC] or phosphatidylglycerol) and cholesterol increases the surfactant's fluidity, so it can adsorb oxygen more efficiently.

The treatment of preterm infants with RDS using surfactants was initially developed in the 1960s, and recent studies have demonstrated an improvement in clinical outcomes.

[full citation needed] This treatment proved ineffective because administration of DPPC alone did not provide any beneficial effects.