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Cyclodextrins (CDs) are widely used in pharmaceutical analysis due to its biodegradability and eco-friendly character. The particular structure of CDs, characterized by hydrophobic cavity, enables the formation of inclusion complexes with variety of organic compounds. As structures lacking chromophores, CDs could not be detected by Photodiode Array (PDA) detector and Corona Charged Aerosol Detector (CAD) was introduced as the most appropriate detector for the formed complexes. The aim of the study was to investigate the degree of complexation between telmisartan, used as a model substance, and b-CD. Moreover, the effect of different b-CD concentrations (5-15 mM) and pH of the aqueous part of mobile phase (3-7) on the degree of complexation was also assessed. The intensity of the formed complex appeared to be the highest when 15 mM b-CD was used for the complexation. Also, it was noticed that the increase in peak areas with an increasing b-CD concentration was more evident at pH 7 in comparison with the same trend at lower pH values. The reproducibility of the measurement was confirmed by low relative standard deviation (RSD) of peak areas within five measurements. These findings support the use of HPLC-CAD methods for studying the process of inclusion complexes formation.

In recent years, there is aim to reduce toxic solvents use in chromatographic techniques. Beta-cyclodextrins (β-CD) are commonly used for this purpose, as substance retention modulators. By increasing their concentration in the mobile phase, generally there is a decrease in analyte retention time, and consequently, a decrease in the organic solvent ratio in the mobile phase. The aim of this study was to investigate β-CD and selected sartans inclusion complexes formation. The emphasis was on the influence of the aqueous phase pH value, the drug-β-CD molar ratio and the organic solvent type on complex formation. The mass spectrometry investigation included characterization of the formed complex drug: β-CD at different molar ratios (1:1, 1:2, 1:5 and 1:10), and at different pH values of the aqueous phase (5, 7 and 9) using triple quadrupole mass analyzer. The mobile phase and solvent in which the complexes were formed consisted of acetonitrile and water mixture (50:50, v/v) and methanol and water mixture (50:50, v/v). Measurements of these complexes signal intensity after electrospray ionization in negative mode. Observed m/z values indicated formation of drug-β-CD in 1:1 ratio at all pH values of water phase and independently of organic solvent type and β-CD ratio. It was noted that formed complex signal intensity increased only by increasing β-CD ratio.

The aim of this work was the preparation of the inclusion complex of naproxen with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) in order to improve the physical and chemical properties of naproxen. The molecular inclusion complexes of naproxen with HP-β-CD were prepared by using the co-precipitation method in the solid state with the molar ratio of 1:1. The structure of the obtained complex was characterized by using FTIR, 1H NMR, UV-Vis and XRD methods. The testing of naproxen photostability by the UV-Vis method indicated the degradation to aromatic ketone, 2-acetyl-6-methoxynaphthalene. FTIR analysis showed that the degradation started 15 days after the exposure of naproxen to daylight while the inclusion complex of naproxen: 2-hydroxypropyl-β-cyclodextrin was photostable for a period of 30 days. [Projekat Ministarstva nauke Republike Srbije, br. TR 34012]

A media consisting of isatin-Schiff bases and its inclusion complexes with β-cyclodextrine was developed to maximize the production of antibiotics Hexaene H-85 and Azalomycine β by Streptomyces hygroscopicus CH-7. The media with β-cyclodextrine inclusion complex of isatin-3-thiosemicarbazone resulted in the maximum antibiotics concentration of 493 µg/cm3 for Hexaene H-85 and 191 µg/cm3 for Azalomycine B. The production of Hexaene H-85 and Azalomycine is higher when β-cyclodextrine complex is added as a nitrogen source, comparing to pure isatin-Schiff base. The maximum concentration of hexaene H-85 in medium with inclusion complex of isatin-Schiff base is 1.4-2.3 times higher than the basal medium. The maximum production of Azalomycine is 2.1-3.4 times higher in media with inclusion complex of Schiff base. During the fermentation process, the nutrient media with β-cyclodextrine inclusion complexes with isatin-Schiff bases affect the strain morphology, since it is in the form of compact pellets, which are formed from short and long, branched filaments [Projekat Ministarstva nauke Republike Srbije, br. III 45001]

The aim of this work is the protection of piroxicam from photodegradation by forming inclusion complex with 2-hydroxypropyl-β-cyclodextrin. Piroxicam:2-hydroxypropyl-β-cyclodextrin molecular inclusion complex was prepared by coprecipitation method with molar ratio of 1:1. Structural characterization of the complex, the corresponding physical mixture and complexing agents of piroxicam and 2-hydroxypropyl-β-cyclodextrin was carried out by X-ray diffraction (XRD), proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR). Photosensitivity to daylight for piroxicam and piroxicam:2-hydroxypropyl-β-cyclodextrin inclusion complex was investigated by Fourier-transform infrared spectroscopy. The investigations show that higher photostability of piroxicam was achieved in complex than in non-complexed piroxicam.