  In this note, we propose in the full generality a link between the BD entropy
introduced by D. Bresch andB. Desjardins for the viscous shallow-water
equations and the Bernis-Friedman (called BF) dissipative entropyintroduced to
study the lubrications equations. Dierent dissipative entropies are obtained
playing with the dragterms on the viscous shallow water equations. It helps for
instance to prove global existence of nonnegativeweak solutions for the
lubrication equations starting from the global existence of nonnegative weak
solutions forappropriate viscous shallow-water equations.
