Radiation-Thermal Synthesis of Copolymers of Chitosan with Acrylamide as a Means of Betulin Delivering

Радиационно-термическим методом с использованием ускоренных электронов получены привитые сополимеры хитозана с акриламидом. Образование привитых сополимеров подтверждено методами ИК‑спектроскопии и гель-проникающей хроматографии. Показано, что эффективность и степень прививки зависят от дозы ионизирующего облучения и с ростом дозы проходят через максимум. Найдены условия получения сополимеров с высоким выходом продукта. Полученные сополимеры использованы для получения композитов бетулина с помощью механохимической обработки. Показано, что скорость выделения бетулина в водный раствор при растворении композита зависит от pH раствора, что позволяет рассматривать механокомпозиты на основе сополимеров хитозана с акриламидом как перспективные средства для контролируемой доставки лекарственных веществGraft copolymers of chitosan with acrylamide were obtained by the radiation-thermal method using accelerated electrons. The formation of graft copolymers was confirmed by IR spectroscopy and gel permeation chromatography. It is shown that the efficiency and degree of grafting depend on the dose of ionizing radiation, and pass through a maximum with increasing dose. The conditions for obtaining copolymers with a high yield of the product were found. The resulting copolymers were used to obtain betulin composites using mechanochemical processing. It has been shown that the rate of release of betulin into an aqueous solution during the dissolution of the composite depends on the pH of the solution, which makes it possible to consider mechanocomposites based on copolymers of chitosan with acrylamide as promising means for controlled drug deliver

Morphological Changes in Betulin Particles as a Result of Polymorphic Transformations, and Formation of Co-Crystals under Heating

Changes in the morphology of betulin crystals during heating at selected temperatures corresponding to polymorphic transformations were investigated. It was shown that the prismatic crystals of starting betulin form III were converted into needles at 120 °C after water removal, followed by the III→II polymorphic transformation. During further heating up to 180 °C, the whiskers of betulin form I were grown. Experiments on betulin heating in the presence of dicarboxylic acids, adipic or suberic showed that the morphological changes can serve as a test for the formation of cocrystals. According to morphological changes, the formation of cocrystals of betulin with adipic acid under heating was identified. The interaction of adipic acid vapor with the surface of betulin crystals was suggested. In contrast, morphological changes in the mixture of betulin and suberic acid under heating provided only the evidence of polymorphic transformations of the components. The results on cocrystal formation by heating were compared with the preparation of cocrystals by the liquid-assistance grinding method. Despite the fact that polymorphic forms with a high surface area were formed when betulin was heated, dissolution studies showed that the starting betulin polymorph III exhibited the highest dissolution rate in comparison with betulin polymorphs obtained under heating

CCDC 834808: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

How good are the crystallisation methods for co-crystals? A comparative study of piroxicam

Additional file 5. MaZda Package v5 RC HG (release candidate: Hugues Gentillon): this pre-release (beta) version contains: 1) MaZda version 5 for achromatic and chromatic image analysis, 3D editing, feature extraction & selection, geometrical features for ROIs; 2) B11 version 3.3 for feature clustering, image segmentation, unsupervised & supervised classification

Mechanochemical Synthesis of Composites in the Betulin-L-Histidine-Arabinogalactan System and Their Physical and Chemical Properties

С целью улучшения биодоступности и расширения спектра фармакологических свойств биологически активного бетулина получены механокомпозиты бетулина с природным водорастворимым полисахаридом арабиногалактаном, с аминокислотой L‑гистидином и в тройной системе бетулин‑L‑гистидин‑арабиногалактан. Образование механокомпозитов подтверждено методами рентгенофазового анализа и ИК‑спектроскопии. Установлено, что при растворении полученных механокомпозитов в воде достигается большая концентрация бетулина в растворе по сравнению с растворимостью исходного веществаIn order to improve bioavailability and expand the range of pharmacological properties of biologically active betulin, mechanocomposites of betulin with natural water-soluble polysaccharide arabinogalactan, with amino acid L-histidine and in the ternary system betulin-L-histidine-arabinogalactan were obtained. The formation of mechanocomposites was confirmed by X‑ray phase analysis and IR-spectroscopy. It was found that when dissolving the obtained mechanocomposites in water, a higher concentration of betulin in solution was achieved compared to the solubility of the starting substanc

Mechanochemical Synthesis of Cocrystals of Betulin with Adipic Acid

Смешанные кристаллы бетулина с адипиновой кислотой получены механохимической активацией при добавлении небольших количеств органических растворителей. Образование смешанных кристаллов подтверждено методами рентгенофазового анализа и ИК-спектроскопии. С целью выбора жидкости для приготовления смешанных кристаллов проведено сравнение растворителей различной полярности. Показано, что смешанные кристаллы бетулина с адипиновой кислотой образуются, если при механической обработке используются растворители, хорошо растворяющие адипиновую кислотуThe cocrystal of betulin with adipic acid was prepared using a liquid-assisted grinding method. The formation of cocrystal was confirmed by powder X-ray diffraction and IR spectroscopy methods. In order to choose a liquid for preparing cocrystal, solvents of different polarity were compared. It was shown that cocrystal of betulin with adipic acid was formed if solvents were used during mechanical treatment, in which the increased solubility of adipic acid was observe

Clathrate Hydrates of Organic Solvents as Auxiliary Intermediates in Pharmaceutical Research and Development: Improving Dissolution Behaviour of a New Anti-Tuberculosis Drug, Perchlozon

There is an urgent need for new drugs to overcome the challenge of the ever-growing drug resistance towards tuberculosis. A new, highly efficient anti-tuberculosis drug, Perchlozone (thioureidoiminomethylpyridinium perchlorate, Pz), is only available in an oral dosage form, though injectable forms and inhalation solutions could be better alternatives, offering higher bioavailability. To produce such forms, nano- and micro-particles of APIs would need to be prepared as dispersions with carriers. We use this case study to illustrate the principles of selecting solvents and excipients when preparing such formulations. We justify the choice of water–THF (19.1 wt % THF) as solvent and mannitol as carrier to prepare formulations of Pz—a poorly soluble compound—that are suitable for injection or inhalation. The formulations could be prepared by conventional freeze-drying in vials, making the proposed method suitable for industrial scaling. A similar strategy for selecting the organic solvent and the excipient can be applied to other compounds with low water solubility