Thin liquid films from a new synthetic pulmonary surfactant preparation

A new pulmonary surfactant with synthetic analogs of surfactant proteins SP-B and SP-C (CHF5633) was studied by the method of thin liquid films (foam and wetting films). For foam films dependences such as probability W for formation of black foam films vs. surfactant concentration (C-s), disjoining (capillary) pressure isotherms (Pi(h)) and film thickness (h) were studied. The minimum CHF5633 concentration for a black foam film formation was established in 75 mu g/cm(3) (after 30 min). The results obtained were compared with those of therapeutic pulmonary surfactant preparations and in particular to Curosurf (R), the one that showed the best profile among the tested animal-derived surfactants with respect to black film formation, stability and homogeneity. It was shown that with respect to stability surfactant CHF 5633 (from W/C curves) was very close to Curosurf (R). The differences involved black foam film thicknesses which for the synthetic surfactant (at 200 mu g/cm(3)) were h = 14.7 nm and for Curosurf (R) (at 200 mu g/cm(3)), h = 12.6 nm, i.e. film thickness of the synthetic surfactant was larger, probably due to the larger quantities of surfactant protein analogs SP-B and SP-C contained in it and/or to the different phospholipid composition. The same was observed for h(C-s) dependence. For wetting films equilibrium thickness vs. degree of hydrophobicity on a solid surface was measured as well as wetting contact angles. Practically no significant difference in the wetting behaviour of the aqueous suspensions of natural surfactant preparation Curosurf (R) and CHF 5633 was established, however about 25% less Curosurf (R) was needed to achieve almost the same wetting behavior. (C) 2016 Elsevier B.V. All rights reserved.