A spray system for production of a matrix which forms in situ is described, this comprising at least one lipophilic component comprising at least one polymer based on glycolic acid and lactic acid and at least one biocompatible solvent having an XlogP3 value of less than 0.2, and at least one hydrophilic component, the at least two components being present separately from one another prior to use and not being mixed until or in the course of spraying, and the components forming a film when sprayed onto human tissue.