Information about shyam

Published on July 21, 2014

Author: nshyamprasadgoud



PowerPoint Presentation: COMPRESSION AND CONSOLIDATION by N.Shyam Prasad M.pharm(pharmaceutics) PowerPoint Presentation: CONTENTS INTRODUCTION FUNDAMENTALS OF POWDER COMPRESSION METHODS COMPRESSION MACHINES CONCLUSION REFERENCES DERIVED PARA METERS PowerPoint Presentation: COMPRESSION the reduction in the bulk volume of a material as a result of the removal of the gaseous phase (air) by applied pressure CONSOLIDATION Involves an increase in the mechanical strength of a material resulting from particle-particle interactions. COMPACTION The compression and consolidation of a 2 phase (solid + gas) system due to an applied force. PowerPoint Presentation: FUNDAMENTALS OF POWDER COMPRESSION Attractive forces exist between particles vander Waal’s, H-bonding, Electrostatic consider a number of granules in a die to which a force is applied PowerPoint Presentation: DERIVED PARAMATERS solid-air interface, angle of repose, mass volume relationship, volume density, compressibilty PowerPoint Presentation: Solid-air interface Cohesion is the attraction between like particle; Experienced by particles in bulk. Adhesion is the attraction between unlike particle; Experienced by particles at surface. PowerPoint Presentation: Angle of repose The maximum angle possible between the surface of pile of non-cohesive (free-flowing) material and the horizontal plane. Angle of repose is an indication of the flow ability of the material. PowerPoint Presentation: Angle of Repose (θ) θ = tan -1 (h/r) where h = height of pile r = radius of the base of the pile Excellent flow ability if θ < 25 o Good flowability if 25 o < θ < 30 o Passable flowability if 30 o < θ < 40 o Very poor flowability if θ > 40 o h r PowerPoint Presentation: True volume (V T ) Granule volume (V G ) Bulk volume (V B ) Relative volume (V R ) V R = V B / V T V R tends to become unity as all air is eliminated from the mass during the compression process. VOLUME Open intraparticulate voids-those with in a single particle but open to the external environment. closed interparticulate voids-those within a single particle but closed to the external environment. Interparticulate voids-the air spaces between individual particles. Mass-Volume relationships PowerPoint Presentation: True density ( ρ T = M / V T ) Granule density ( ρ G = M / V G ) Bulk density ( ρ B = M / V B ) Relative density ( ρ R = M / V R ) Types of Density: M is the mass of powder DENSITY : The ratio of mass to volume is known as the density of the material PowerPoint Presentation: Carr’s (Compressibility) Index = [(V B – V Tap ) / V B ] x 100 ≈ E where V B = Freely settled volume of a given mass of powder V Tap = Tapped volume of the same mass of powder ≈ V T Measuring Compressibility: Carr’s (Compressibility) Index = [( ρ Tap – ρ B ) / ρ Tap ] x 100 ≈ E where ρ B = Freely settled bulk density of the powder ρ Tap = Tapped bulk density of the powder ≈ ρ T Compressibility: The ability of the powder bed to be compressed (under pressure) and consequently be reduced in volume. PowerPoint Presentation: Measuring Compressibility Excellent flowability if 5 < Carr’s Index < 15 good flowability if 12 < Carr’s Index < 16 Passable flowability if 18 < Carr’s Index < 21 poor flowability if 23 < Carr’s Index < 35 Very poor flowability if 33 < Carr’s Index < 38 Very very poor flowability if Carr’s Index > 40 PowerPoint Presentation: METHODS Direct Compression PowerPoint Presentation: Dry Granulation PowerPoint Presentation: Wet Granulation PowerPoint Presentation: COMPRESSION MACHINES Hopper for holding and feeding granulation to be compressed Dies that define the size and shape of the tablet Punches for compressing the granulation within the dies Cam tracks for guiding the movement of the punches Feeding mechanisms for moving granulation from the hopper into the dies Components of compression machines PowerPoint Presentation: Single Punch Machine PowerPoint Presentation: Multistation tablet press PowerPoint Presentation: CONCLUSION PowerPoint Presentation: Adolfsson , Å., Caramella , C., Nyström , C., 1998. The effect of milling and addition of dry binder on the interparticulate bonding mechanisms in sodium chloride tablets. Int.J . Pharm. 160, 187-195. Adolfsson , Å., Gustafsson , C., Nyström , C., 1999. Use of tablet tensile strength adjusted for surface area and mean interparticulate distance to evaluate dominating bonding mechanisms. Drug Dev. Ind. Pharm. 25, 753-764. Adolfsson , Å., Nyström , C., 1996. Tablet strength, porosity, elasticity and solid state structure of tablets compressed at high loads. Int. J. Pharm. 132, 95-106. Reference PowerPoint Presentation: THANKYOU

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