Introduction. Application of pharmacological forms based on nanomaterials is a promising methodological approach to increase the therapeutic efficacy of nonpolar drugs by increasing their bioavailability. One of the most important parameters that makes it possible to assess the effectiveness of the use of pharmacological forms is the release profile of the drug from the nanocarrier. The role of the kinetic characteristics of drug liberation from nanocarriers has not been sufficiently studied due to the existing limitations of the analysis of mass transfer in complex biological systems.

The aim of this work is to compare the equilibrium and kinetic characteristics of the distribution of the photosensitizer Temoporfin when the photosensitizer is bound to monomeric or polymeric forms of β-cyclodextrin derivatives.

Materials. Temoporfin was provided by Biolitec^® (Germany). The cyclodextrin methyl-β-cyclodextrin was purchased from AraChem (Netherlands). β-cyclodextrin polymer and carboxymethyl-β-cyclodextrin were purchased from Cyclolab (Hungary).

Results. The fluorescence features of Temoporfin in complexes with β-cyclodextrin derivatives were studied, and the binding constants were determined. According to the results obtained, all cyclodextrin derivatives exhibit a high affinity for the sensitizer. Using the developed spectral techniques, the kinetics of Temoporfin release from complexes with cyclodextrins in the presence of model biological membranes or serum proteins were analyzed. The processes of association and dissociation of photosensitizer molecules from nanocarriers strongly depend on both the physicochemical properties of cyclodextrin molecules and their structure. Despite their lower affinity, polymeric cyclodextrins are able to delay sensitizer molecules for a significantly longer period of time.

Conclusions. Our results show that fluorescent techniques are highly informative in studying the processes of sensitizer redistribution between nanostructures. According to the data obtained, the rate of drug release from complexes with nanomaterials varies in a wide range, which should be taken into account when analyzing the pharmacokinetics of drugs introduced as part of complexes with a nanocarrier.