Direct compression Dotaz Zobrazit nápovědu
Tablety jsou nejpoužívanější lékovou formou. Jejich výhodou je dostupnost, snadné podání, dobrá stabilita a nízká cena. Nejjednodušší technologií pro výrobu tablet je přímé lisování, ačkoliv při použití této metody je nutné překonat určité obtíže, spojené zejména s hmotnostní a obsahovou stejnoměrností, disolucí a radiální pevností tablet. Společně zpracované pomocné látky obsahující běžně zpracované směsi plniv, pojiv, rozvolňovadel, lubrikantů a dalších pomocných látek, se v dnešní době používají stále častěji. Tyto směsi jsou vyráběny různými technologiemi, zejména sprejovým sušením, granulací ve fluidním loži, vlhkou granulací, granulací tavením, suchou granulací a společnou krystalizací. Tento článek popisuje pomocné látky, které se obvykle používají k vytvoření společně zpracovaných směsí, uvádí výrobní technologie a komerčně dostupné společně zpracované pomocné látky pro přímé lisování tablet.
Tablets are the most frequently employed dosage form. Their advantage lies in their availability, easy administration, good stability, and low price. The easiest technology to produce tablets is direct compression, even though the use of the method requires overcoming many obstacles, mainly related to content uniformity and variation of mass, disintegration, dissolution, and radial hardness of tablets. "Co-processed excipients", containing commonly processed blends of fillers, binders, disintegrants, lubricants, and other excipients are more and more widely used nowadays. These mixtures are manufactured by various technologies, chiefly by spray-drying, fluid bed granulation, wet granulation, melt granulation, dry granulation, and co-crystallisation. This review article lists excipients used usually to constitute co-processed excipients, technologies, and commercially available co-processed excipients for direct compression.
- Klíčová slova
- společně zpracované pomocné látky, lisování, fyzikální vlastnosti,
- MeSH
- farmaceutická technologie * metody MeSH
- farmaceutická vehikula MeSH
- farmaceutické pomocné látky * klasifikace MeSH
- tablety * MeSH
- Publikační typ
- přehledy MeSH
The paper evaluates and compares the strength and disintegration time of tablets and the energy profile of compression in dependence on compression force in the coprocessed dry binders LubriToseTM SD and LubriToseTM AN. These substances are further compared in these parameters with the physical mixtures of the pertinent lactoses with various lubricants in a concentration of 4 %. The lubricants employed included glycerol monostearate, magnesium stearate, Poloxamer 407, and sodium stearyl fumarate.
Tensile strength and disintegration time of tablets from aglomerated α-lactose monohydrate or anhydrous β- lactose as well as the energy profile of compression (at 11 kN) were evaluated in dependence on the lubricant (Mg stearate) concentration and an addition of microcrystalline cellulose (25 %). No statistically significant differences were found between the corresponding values of tensile strength for tablets from both lactoses. Microcrystalline cellulose increased the strength, shortened the disintegration times and markedly decreased the differences in compression energies and plasticity of both types of tablets. Mg stearate prolonged the disintegration times and markedly decreased the tablet strength only in the presence of microcrystalline cellulose. The disintegration times were markedly longer for the tablets from anhydrous β-lactose. The total energy of compression and plasticity were higher for aglomerated α-lactose monohydrate tablets.
Good flow and compaction properties are necessary for the manipulation of particulate material in the pharmaceutical industry. The influence of the addition of an alternative sweetener, rebaudioside A, in a concentration 0.2% w/w and 0.5% w/w on the flow, shear and compaction properties of sorbitol for direct compaction, Merisorb® 200, was investigated in this work. Rebaudioside A worsened the flow properties of sorbitol: the Hausner ratio, the compressibility index and the mass flow rate through the aperture of a model hopper. Using a Jenike shear cell revealed a significant increase in cohesion leading to the decrease of the flow function; moreover, the addition of rebaudioside A increased the total energy for compression of tablets and plasticity estimated by the force-displacement method. Finally, the tablets showed a higher tensile strength and needed longer time to disintegrate compared to the tablets made of sorbitol itself. In view of the results for the free-flowable excipient, sorbitol, the effects of stevia even for a 0.2% w/w concentration have to be carefully considered, particularly whenever used in pharmaceutical formulations of poor flow properties.
Evaluation of viscoelastic properties of four pharmaceutical fillers of different chemical structure using a stress relaxation test is described. The obtained values express not only the elasticity and plasticity of the material, but also describe the processes inside the compressed material. For each of the fillers tested, three modules of elasticity and three modules of plasticity were calculated. Different modules were found in the polymeric and crystalline fillers. Dehydrated dicalcium phosphate possesses a high module of plasticity comparable to that of microcrystalline cellulose. The strength of dicalcium phosphate tablets is very low in comparison to those from microcrystalline cellulose.
