PREPARATION, CHARACTERIZATION AND STUDIES OF PHYSICOCHEMICAL AND BIOLOGICAL PROPERTIES OF DRUGS COATING LACTOSE IN FLUIDIZED BEDS

Objective: Study physicochemical properties and activity of biotechnological drugs coating lactose particles in fluidized beds for the development of a prospective approach of their identification. Methods: Lactose monohydrate as pharmaceutical excipient; affinity-purified polyclonal rabbit antibodies to recombinant human interferon-gamma as a drug substance; Pilotlab fluid bed apparatus was used for lactose powder saturation with solutions of pharmaceutical substances to the point of granulation (pelletizing); inverse light scattering method (2D-LS) for analysis of micron vibrations frequency spectra of samples surfaces for light intensity distribution in time by values of d1, d2, d3 primary descriptors; low angel and dynamic laser light scattering (LALLS, DLS) methods for distribution of lactose-water (LW) supramolecular complexes into volume fractions (micron "size spectra"), using the Master Sizer 2000 instrument and Zeta Sizer Nano ZS instrument in the nanoscale; Spirotox method for research of biological activity to determine the activation energy (Ea) values of cell death in solutions of tested samples. Results: Changes in 2D-LS scattering time on sample surfaces, described by topological descriptors, made it possible to clearly differentiate the intact lactose from fluidized samples by specific corridors in coordinates di=F(t). The calculated activation energy (Ea) values of cell biosensor death process in solutions of drugs coating lactose allow to characterize the biological activity of it in the initial (by Ea increase) and activated state (by Ea decrease) after the creation of intra-laboratory transmucosal conditions. A unique dimensional spectrum of LW complexes in the nanoscale range was obtained by DLS. The differences between samples in the distribution of LW complexes in the size range from 1 µm to 125 µm was showed by LALLS. Conclusion: The developed approach, including Сhemometrics, laser and biotesting methods can be used for qualitative the analysis tasks as well as for analytical control of the fluidization process in cases where identifiable pharmaceutical substances are not distinguishable by traditional analytical methods

Experimental Model of Recurrent Corneal Erosion

Introduction. In a number of pathological conditions accompanied by the basement membrane defects, such as chemical or thermal burns, mechanical trauma, Sjögren’s syndrome, neurotrophic keratopathy or some corneal dystrophies, in which conditions are created independent epithelialization is weakened or becomes impossible. This condition was named recurrent corneal erosion (RCE). For the experimental study of the regenerative processes and evaluation of the effectiveness of new treatments, a standardized and reproducible RCE model is needed. Several RCE models are known: chemical, bacterial. The disadvantages of such models are the labour intensity of their implementation and a relatively high cost. The proposed method makes it possible to create the necessary conditions for local inflammation and destruction of adhesive molecules using the energy of ultraviolet (UV) irradiation. In this study, an experimental RCE model in rabbits has been proposed.Purpose. To create a reproducible standardized experimental model of recurrent corneal erosion.Materials and methods. The studies were conducted in 8 chinchilla rabbits (16 eyes). After local instillation (0.5 % alkaine solution) and retrobulbar anesthesia (2 % lidocaine solution), superficial deepithelialization of the cornea was performed by mechanical removal of its epithelium with a blunt scraper; and the quality of deepithelialization was assessed by staining the surface with 2 % fluorescein solution. In the optical zone with a diameter of 4 mm, local UV irradiation of the cornea was performed with exposures of 30 and 45 minutes.Results. In case of 30-minute exposures, the epithelialization of the cornea subjected only to mechanical deepithelialization was observed since Day 3 in the form of concentric epithelial growth. On Day 14, a complete epithelialization of the cornea was observed, along with the formation of superficial newly formed vessels along the limbus. On Day 24, the vascular injection significantly decreased; and no erosion was observed. After 45-minute exposure without treatment, the regeneration occurred much slower; and a complete epithelialization had been achieved by Day 34 of the experiment, by the time the newly formed vessels grew to the epithelial defect zone. It was noted that since Day 86, the turbidity in the irradiation area persisted, as well as the inflammatory infiltrate.Conclusions. The proposed method makes it possible to reproduce RCE, in which there is an alternation of epithelialization and deepithelialization of the irradiated corneal area through 30 days of the experiment and is arrested only after the ingrowth of surface vessels into the affected area. At that, the non-irradiated cornea is epithelialized by Day 7 of the experiment