Calorimetric Investigation of the Relaxation Phenomena in Amorphous Lyophilized Solids

Studying the thermal history and relaxation of solid amorphous drug product matrices by calorimetry is a well-known approach, particularly in the context of correlating the matrix parameters with the long-term stability of freeze-dried protein drug products. Such calorimetric investigations are even more relevant today, as the application of new process techniques in freeze-drying (which strongly influence the thermal history of the products) has recently gained more interest. To revive the application of calorimetric methods, the widely scattered knowledge on this matter is condensed into a review and completed with new experimental data. The calorimetric methods are applied to recent techniques in lyophilization, such as controlled nucleation and aggressive/collapse drying. Phenomena such as pre-Tg events in differential scanning calorimetry and aging shoulders in isothermal microcalorimetry are critically reviewed and supplemented with data of freeze-dried products that have not been characterized with these methods before.

Experimental Determination of the Dose of Energy Received by Seed Material After Irradiation by Electric Field

Introduction. Maximum use of potential biological potential of seed material is among the ways to increase the production and to improve the quality of agricultural products. In view of the above, various methods of preseeding treatment of seeds of agricultural crops by means of electromagnetic fields are used. At the same time there is insufficient clarity of reproducibility of the results of radiation. Problem Statement. However, the conventional methods for determining germination capacity require a wide range of equipment and materials and are time-consuming. Therefore, the search for new methods of pre-seeding treatment and the development of rapid calorimetric methods are promising directions of research. Purpose. To study the effect of irradiation on seed material, by calorimetric methods. Materials and Methods. To determine the caloric value of seed material, two batches of Scarlet barley seeds are taken, one of which is irradiated with an electric field. The caloric value of the grain has been determined using the calorimetric device B-08M, according to DSTU ISO 1928:2006. Results. The results of quantitative indicators of temperature change of the irradiated and reference batch of barley grain have been presented in a graphical form to visualize the effect of irradiation. The analysis of results has shown that the non-irradiated seeds have a germination capacity of 82%, while for the irradiated seeds this index is equal to 88%. Respectively, their caloric value is 10 842 kJ/kg and 11 985 kJ/kg, i.e. differs by 10.5%. An experimental dependence has been established that to increase germination by 1% it is necessary to increase the caloric value of seed mass by approximately 1.83%. Conclusions. A 10-11% increase in the caloric value of the seeds after irradiation indicates that the irradiation process is realized. The use of calorimetry methods can be recommended as a seed material irradiation quality control method.

The impact of counterion on the metastable state properties of nitrosyl ruthenium complexes

Complexes of the trans-[RuNO(NH3)4F]2+ cation with noble-metal anions [PtCl6]2−, [PdCl4]2−, and [PtCl4]2−, and perchlorate ClO4− were synthesized, the photo-generated linkage isomers were studied by spectroscopic and calorimetric methods.