SELECTION OF A CRYOPROTECTOR FOR PRODUCTION A LYOPHILIZED LIPOSOMAL DOSAGE FORM OF THE INDOLOCARBAZOLE DERIVATIVE LHS‑1269

Introduction. One of the key tasks in freeze‑drying of drug is to choose the optimal cryoprotector that provides a high‑quality lyophilized product.The aim of research. Selection of cryoprotectant and its concentration for the preparation of lyophilizate of the liposomal dosage form of the indolocarbazole derivative LHS‑1269.Materials and methods. Substance LHS‑1269 ≥99 % (N. N. Blokhin National Medical Research Center of Onco logy), egg phosphatidylcholine Е РС S (Lipoid, Germany), cholesterol ≥99 % (Sigma‑Aldrich, Japan), polyethylene glycol‑2000‑distearoyl phosphatidylethanolamine (Lipoid, Germany), mannose‑d (+) 99 % (Kaden, Germany), sucrose (Himmed, Russia), trehalose dihydrate (Himmed, Russia). To obtain LHS‑1269 liposomes, the Bangham method was used in modification for hydrophobic substances with subsequent extrusion of the dispersion of multilayer phos‑ pholipid vesicles. The prepared liposomal dispersion was dosed into vials of 6 ml and lyophilized in the freeze‑dryng chamber using the «step‑by‑step» freezing mode. LHS‑1269 liposomes were analyzed before and after freeze‑drying using laser scattering spectroscopy and determination of the electrophoretic mobility of particles.Results. To prevent the destruction of LHS‑1269 liposomes during lyophilization, substances from the carbohy‑ drates class – mannose, sucrose and trehalose – were studied in two concentrations. In the course of compara‑ tive evaluation of the obtained lyophilizates in terms of quality, appearance, rehydration, size and zeta potential of liposomes before and after sublimation, it was found that sucrose introduced into the liposomal dosage form LHS‑1269 in the molar ratio sucrose / egg phosphatidylcholine 5:1 has optimal cryoprotective properties.Conclusion. As a result of the study, the optimal cryoprotector and its concentration were selected, which ensure the production of high‑quality lyophilizate of the liposomal composition of the indolocarbazole derivative LHS‑1269.

56 THE VIABILITY AND LONGEVITY OF OGYE CHICKEN FROZEN SEMEN WITH MITOTEMPOL, MITOCHONDRIA-SPECIFIC ANTIOXIDANT

Semen from Korean Native Black roosters (Ogye) was cryopreserved with 8% N-Methylacetamide (MA) in HS-1 diluent, of the following composition (per 100 mL): glucose 0.2 g, trehalose dihydrate 3.8 g, l-glutamic acid monosodium salt 1.2 g, potassium acetate 0.3 g, magnesium acetate tetrahydrate 0.08 g, potassium citrate monohydrate 0.05 g, BES 0.4 g, Bis-Tris 0.4 g, and gentamicin sulfate 0.001 g. Ogye semen was collected 2 times a week by dorsal-abdominal massage and cooled into ice slurry. During dilution, semen was diluted by 2 steps. First, HS-1 diluent that was supplemented with respective concentration of MitoTEMPOL, mitochondria-specific antioxidant was added into fresh semen with same volume. Second, after waiting for 10 min, 16% MA containing diluent was added into first diluted semen so the final concentrations of MA were adjusted to 8%. The concentration of the MitoTEMPOL of first diluent was adjusted to 0.1, 1, 5, and 10 μM. After freezing for 30 min by exposure to liquid nitrogen vapor 4 cm above the surface of liquid nitrogen, the semen was thawed 5°C for 2 min 1 to 3 weeks later. The viability and longevity of thawed Ogye semen were analysed by sperm movement methods. Briefly, 5 μL of thawed semen was placed onto a Makler chamber and the movement of spermatozoa was recorded for 10 s by digital camera and saved as movie files on the computer. With digital rewinding for 1 s of saved movies, the non-motile and motile sperm was counted using a manual counter. The resulting numbers of respective spermatozoa were analysed by Student t-test. The 0.1 and 1 μM treated semen showed significant increases in viability compared with control, 5 μM and 10 μM MitoTempol (77.3 and 84.2% v. 65.4, 53.2, and 21.5%; P < 0.05). The longevity of frozen/thawed Ogye semen for 3 h was also higher in 0.1 and 1 μM treated groups than control, 5 μM, and 10 μM (67.5 and 54.2% v. 36, 5.2, and 1.2%; P < 0.05). With these results, utilisation of mitochondria-specific antioxidant for freezing of Ogye spermatozoa could increase the viability and longevity of frozen-thawed semen. However, treatment with concentrations >1 μM showed negative effects on freezing of Ogye chicken semen. These findings could be helpful for cryobanking of rooster semen for preservation of selected breeders from malignant viral avian disease.

Trehalose dihydrate fromTremella fuciformis

The title compound, C12H22O11·2H2O {systematic name: 6,6′-oxybis[2-(hydroxymethyl)-3,4,5,6-tetrahydro-2H-pyran-3,4,5-triol] dihydrate}, is a disaccharide, which was isolated fromTremella fuciformis. The molecule contains two six-membered rings, both of which adopt a chair conformation. Extensive O—H...O hydrogen bonds occur in the crystal structure.

Preparation of Porous Alumina Powder Using Sol Containing Trehalose Dihydrate

To obtain alumina powder with large surface area, the precursor sol was prepared by hydrolysis of aluminum isopropoxide and then mixing with trehalose dihydrate. The porous alumina powders were prepared by drying and calcination at 500-900 °C. The specific surface area went up to over 340 m2/g in the alumina powder calcined at 500 °C. The mean pore diameter of the alumina powder was increased by the addition of treahalose dihydrate. The porous alumina powder was successfully prepared by the addition of trehalose dihydrate to the precursor sol.