Author/Editor     Kočevar, J
Title     Vloga kristalizacije pri oblikovanju zdravilnih pripravkov
Translated title     The role of crystallisation in pharmaceutical dosage forms formulation
Type     članek
Source     Farm Vestn
Vol. and No.     Letnik 44, št. 2
Publication year     1993
Volume     str. 55-74
Language     slo
Abstract     The goal of this article is to introduce the mechanism of the crystal growth, and factors influencing the formation of different polymorphs and crystal habits, together with the modes of their influence on the formulation of dosage forms. Crystallisation is the process of crystal formation and growth. The supersaturation of the system is the critical condition wether the crystallisation process takes place or not. The mechanism of crystallisation involves two steps: nucleation and arranging of molecules around the nuclei. There are more theories about the crystal growth: surface energies and adsorption layer theories based on thermodynamic approach to the crystallisation, and the diffusion theory considering it as a diffusion process. Different polymorphs and crystal habits of drugs, are the reflex of conditions during crystalisation process. They determine the thermodynamic stability of the formulation during its shelf-life, but the troubles may appear during the formulation process, already. So it is neccessary to know all existing polymorphs of the drug, before the production of the final preparation starts, because polymorphs will decide about the physical stability of the final product (suspensions, ointments, suppositories, solutions, etc.).
Descriptors     DOSAGE FORMS
CRYSTALLIZATION
THERMODYNAMICS
SUSPENSIONS
OINTMENTS
SOLUTIONS
SUPPOSITORIES
TABLETS
CAPSULES