Powder Quantachrome Hausner Ratio Tablets & …

1 BTablets & CapsulesPowder density in Solid Dosage FormsBoth active and inactive (excipient) compoundsare used in the manufacture of solid dosageformulations, Tablets and capsules. Thesepowders possess many properties or characteristicsand exhibit certain behaviors as a result. Tapped DensityOne important characteristic is tapped bulkdensity, or simply tapped (tap) density : t hat is, th emaximum packing density of a Powder (or blendof powders) achieved under the influence of well-defined, externally applied forces. The minimumpacked volume thus achieved depends on anumber of factors including particle size distribution,true density , particle shape and cohesiveness dueto surface forces including moisture.

2 Therefore,the tap d ensity of a material can be used to predictboth its flow properties and its compressibility(see right sidebar as to how). These are just two ofthe many parameters which are important in theoverall tabletting process - which requires thatloose powders be compacted into a durable solidform with the correct mechanical strength,porosity and dissolution characteristics and incapsule-filling performance. Compressibility I ndex & Hausner RatioThe two most commonly used measures of t herelative importance of interparticulate interactions arethe compressibility index (often referred to asCarr s Index [1]) and the Hausner Ratio [2] (seeright sidebar).

3 V and D represent powdervolume and density respectivel y, subscript o denotes the initial or untapped state and f th efinal or tapped state. In free-flowing powders th einitial bulk and tapped densities will be moresimilar than in poor flowingpowders which yieldgreater differences between the two values. Autotap & Dual AutotapThe Autotap and two-sample Dual Autotapconform to USP616 , for Tapped density (Method II). The measuring cylinder containingthe Powder sample is dropped a height of 3mm(1/8 ) at a rate of approximately 250 drops perminute. Both Autotaps feature a drop counterwhich can be set to any value from 1 to 9999.

4 Anoptional l ock-out mechanism i s available toprevent tampering with a preset number ofcounts. Quantachrome s Autotaps therefore cancontribute a vital role in t he dev elopment andassurance of solid dosage formulations in thepharmaceutical industry. References[1] Carr, (1965) Chem Eng. 72,163-168 [2] Hausner , (1967) Int J Powder ,7-13[3]F. P odczeck, (1998) in "Particle-particle Adhesion in Pharmaceutical Powder Handling"Imperial College Press, London, p108[4] Ludde and K. Kawakita, (1966) Pharmazie21, 393-403 For more information about measurement capabilitiesand how to submit an evaluation sample, contactQuantachrome Instruments by phone: ( 561) , fax: ( 561) 7 , email: visit : Martin A.

5 Thomas , Director of Business DevelopmentQuantachrome Instruments 07158 | No images/charts/text can be reproduced/used without permission. 2005-2010 Quantachrome CorporationPowder & Porous Materials CharacterizationParticle Size Analysis? Is the entire size distribution represented in the small scoopful you just putinto your analyzer? Pr obably not,unless you split the original sample on aRotary Riffler. Reduce variability in your particle size your next sample a representative about Rotary Rifflers from Quantachrome at Instruments Dual Autotap. The usefulness of the two simple ratiosbelow, both based on the decrease inpowder volume during tapping, i s in t heirability t o predict flowability.

6 The lowerthe number, the more free-flowing thepowder. An increase in t he value isproportional t o adhesion and frictionproperties of a Powder [ 3], including(attractive) triboelectric s Index(Compressibility I ndex)100*(Vo- Vf)Vo100*(Do- Dff)D=For More Information:Please avail yourself of the easy access to ourexperts regarding Powder and porous materialscharacterization. Quantachrome specializesnot only in tap density apparatus but also truedensity pycnometers plus surface area, poresize and water sorption us at: or visit uson our website a t density EquationsHausnerRatioVoVf=DfDoThe dynamics of the compression ofthe Powder mass can be furtherevaluated by using the:Kawakita Equation [4]Nc=Na+1abN =number of ta psc = a =Carr s Index (Compressibility Index)b =constant related to cohesivenessand shear strengthVo- VVo((==By plotting vs N, the parameters aand b can be evaluated graphically.))

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