The spatial description of the regular, structured layout of crystals is defined using a mathematical model, a According to this, the space-lattice is a regular, infinite array of zero-dimensional points (lattice space-lattice. in space. points) Definition of crystal: 1) state material with space-lattice structure, 2) anisotropic in certain regards, 3) homogenous discontinuity. for crystals always exhibit directional properties. for there is great distance between Anisotropic, Discontinuity, crystal-forming atoms, therefore space filling is discontinuous, imperfect. Depending on their habit, crystals can be: 1) isometric, 2) needlelike, 3) columnar, 4) tabular or 5) lamellar. Fig. habits is the shape, the external appearance of crystals. In pharmaceutical technology its significance is in Crystal its effect on pressability, facility and fluidity, while in terms of biopharmacy it can influence biological applicability. established a formula about the correlation between the numbers of a crystal’s faces, vertices and edges: Euler f + v = e + 2 (1.) number of f number of vertices v number of e The concept of unit cell has been introduced by Unit cells possess the attributes of the complete lattice Bravais. structure and its symmetric relationships, thus it is the smallest unit of the crystal lattice. In theory, the whole crystal could be constructed by translating the unit cell in parallel with the three directions of space. Fig. cell If a lattice node is selected as starting the other lattice nodes can be accessed by translation: (2.) translation translations connecting the starting point with adjoining lattice nodes
The spatial description of the regular, structured layout of crystals is defined using a mathematical model, a space-lattice. According to this, the space-lattice is a regular, infinite array of zero-dimensional points (lattice points) in space. Definition of crystal: 1) state material with space-lattice structure, 2) anisotropic in certain regards, 3) homogenous discontinuity. Anisotropic, for crystals always exhibit directional properties. Discontinuity, for there is great distance between crystal-forming atoms, therefore space filling is discontinuous, imperfect. Depending on their habit, crystals can be: 1) isometric, 2) needlelike, 3) columnar, 4) tabular or 5) lamellar. Fig. habits Crystal is the shape, the external appearance of crystals. In pharmaceutical technology its significance is in its effect on pressability, facility and fluidity, while in terms of biopharmacy it can influence biological applicability. Euler established a formula about the correlation between the numbers of a crystal’s faces, vertices and edges: f + v = e + 2 (1.) f number of v number of vertices e number of The concept of unit cell has been introduced by Bravais. Unit cells possess the attributes of the complete lattice structure and its symmetric relationships, thus it is the smallest unit of the crystal lattice. In theory, the whole crystal could be constructed by translating the unit cell in parallel with the three directions of space. Fig. cell If a lattice node is selected as starting the other lattice nodes can be accessed by translation: (2.) translation translations connecting the starting point with adjoining lattice nodes
2011-0016_01_the_theory_and_practise_of_pharmaceutical_technology.docx