Introduction. The use of peptides that penetrate the cell without the participation of membrane proteins and are capable of intracellular transport of low molecular weight substances associated with them opens up a new stage in the development of targeted drug delivery to therapeutic targets.

Aim. Evaluation of the effect of prostatic peptides of Vitaprost^® (prostate extract) on the transmembrane transport of the antimicrobial drug lomefloxacin.

Material and methods. In the first series, the effects of prostatic peptides on the ability of lomefloxacin to pass through artificial membranes by passive diffusion (PAMPA method – parallel artificial membrane permeability assay) were studied. In the second series, the effects of prostatic peptides on the cell permeability of lomefloxacin were studied in the Caco-2 model.

Results. Comparative study of effective membrane permeability (logPe). for lomefloxacin in the absence (control group) and presence of prostatic peptides (a mixture of prostate extract at a concentration of 10 mg/ml) showed that the combined use of lomefloxacin and prostatic peptides leads to a significant increase in the logPe value, an increase of 29% on average. The specific nature of the identified interaction was confirmed: the addition of beta-mercaptoethanol (BME) to the donor compartment did not affect the permeability of pure lomefloxacin, but suppressed the cargo effect of prostatic peptides. The permeability coefficient (Papp) calculated on the Caco-2 model for lomefloxacin in combination with peptides was 13.04±1.80×10^-6 cm/s, while for lomefloxacin it was 10.31±0.76×10^-6 cm/s.

Conclusion. Comparison of the obtained data of two series of experiments indicates the presence of a direct cargo effect of prostatic peptides on the transmembrane transport of lomefloxacin in vitro.