N.A. Polyakov, M.M. Astrahanova, V.A. Dubinskaya, V.A. Bykov

Excepients are a part of tabletes, providing flowability, compactability, durability, solubility and bioavailability of grug. Recently, due modern industrial processing, new types of lactose with the improved properties for pharmaceutical application, such as lactose 80м (mersh), used for dry pressing, and lactose-tabletosa 80 which apply in the course of wet granulation are received. Unlike α-lactoses new forms of excepients have other physicochemical parameters, such as, moisture exchange and temperature parametres which knowledge is important for technology of drug. In this connection, the purpose of the given work was definition of thermodynamic parametres and hydration of new types of lactose, and also change of these parametres in the course of experimental ageing. For investigation following methods have been used: a drying method at 105 ºС, recommended by Russian XI pharmacopoeia, Fisher's method, isotermic vapor sorbtion method at relative humidity range from 3 to 98 %, differential scaning calorimetry, IR-spectroscopy and method of accelerated ageing at temperature 50 ºС during time equivalent to 1 and 2 years of storage. Lactose 80 (мersh) and lactose-tabletosa 80, represent various technological products α-lactoses, and differ in water content and thermodynamic characteristics. They have different value of individual parametres endoeffects, the reason of it, is various producing technology of raw materials. Experimental ageing leads to increase water content studied samples, that, possibly, can be due structural changes, leading to formation intermolecular bond, it may be also, that the substance part decompose. This suggestion proves to be true data in hydration of lactose-tabletose 80 and lactose 80м. Hydration of both samples after the accelerated ageing was decreased. However, thermodynamic parametres and IR-spectroscopy do not fix presence of structural changes in studied samples after the accelerated ageing equivalent to 1 and 2nd years of storage.