Summary: р(VA-co-DMAPS) latex nanosystems with two different compositions have been synthesized by interfacial emulsifier-free emulsion copolymerization and loaded with Metoprolol tartrate. The mole fractions ratio between VA and DMAPS in the initial monomer feed was 0.98/0.02 (copolymer 1); 0.95/0.05 (copolymer 2). It has been shown that the copolymerization method applied (no emulsifier added) renders copolymer nanoparticles with narrow size distribution. SEM micrographs of the synthesized latexes are presented. It is seen that the latex particles have a regular spherical shape. It is shown that the average diameter of latex nanoparticles decrease with increasing mDMAPS. The nanoparticles, based on the copolymer 1 provide sustained of the release of the drug up to the 8th hour. This is very positive result and can be concluded that copolymer 1 is very suitable as drug delivery nanosystem for a great number of hydrophilic drugs, e.g. Metoprolol tartrate. The change in 0.03 mDMAPS in copolymer 2 leads to a significant difference in release kinetics. The 90% of the drug is released for 3.5 hours, which makes impossible to control the process. Copolymer 2, as well as compositions with a higher concentrations of DMAPS can be used with drugs with very low solubility and good absorption, where its solubilizing effect can be used, which can improve the bioavailability of these drugs.