A process can be used for preparing nano- or microparticles containing a carrier-polymer and a biologically active ingredient. The process is a solvent emulsion process involving an organic phase (OP) and an aqueous phase (AP) to form an emulsion. In the case of an oil-in-water emulsion (O/W), the organic phase (OP) contains the biologically active ingredient dissolved or dispersed therein. Alternatively, in the case of a water-in-oil emulsion (W1/O), the aqueous phase (AP) contains the biologically active ingredient dissolved or dispersed therein. The organic phase (OP) is saturated with the salt-containing aqueous phase (AP) and vice versa.