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Browsing by Subject "pitkitetty lääkeaineen vapautuminen"

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  • Heiman, Johanna (2012)
    This work evaluated the use of roller compaction as granulation method for hydroxypropyl methylcellulose (HPMC) based hydrophilic extended release matrix tablets. Roller compaction is a dry granulation method where powder material is fed through a hopper between two counter-rotating rolls and pressed into a ribbon like compact. The compact is thereafter milled to obtain granules. Two full factorial experimental designs (DoE) were set up using two model active pharmaceutical ingredients (API). Paracetamol was chosen as a model for a highly soluble API that deforms mainly by fragmenting, whereas ibuprofen was used as a model for poorly soluble and plastically deforming API. The effect of process parameters, the roll pressure and the ratio between feeder screw speed and roll speed as well the effect of particle size of API and HPMC on the manufacturability and release robustness were investigated. Both compositions with medium drug load were successfully compacted into ribbon. Roller compaction increased the particle size and bulk density of the tablet mass. However, the methods used for evaluation of flow properties gave contradictive results on whether the flow properties were enhanced after dry granulation. The loss of compactibility after granulation was observed, as the tensile strength of tablets prepared of granules was in most cases lower than that of directly compacted powder. Exceptionally, two of the ibuprofen granulations showed compactibility similar to that of the initial powder blends. Increased roll pressure resulted in denser ribbon and narrower particle size distribution for granules. However, high roll pressure had a tendency to decrease the tablet tensile strength. This is most probably due to the particle size enlargement and work hardening phenomenon during the double compaction. The use of large particle size HPMC improved the permeability of the powder blend and the flow properties of the granulations. Tablet dissolution testing showed that the large sized HPMC particles were unable to percolate through the tablet and form a consistent network. Roller compaction helped to break down the large HPMC agglomerates and distribute them more evenly within the tablets. No significant difference in release profiles was observed for tablets prepared using granules roller compacted with different parameters.