  We extend the Fock-Tani formalism to include the meson-baryon interaction.
The Fock-Tani formalism is a first principle method which allows the use of
field theoretic methods for treating systems of composite particles. An
application of this general result can be the $K^{+}N$ system which is now
reconized as much more suitable system for the investigation of the short range
nature of the hadronic repulsion.
