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Development of hot-melt extrusion as a novel technique for the ...

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2.6 Evaluation <strong>of</strong> tabletsThe prepared tablets were evaluated <strong>for</strong> <strong>the</strong> uni<strong>for</strong>mity <strong>of</strong> thickness, hardness (Erweka TBH28, Frankfurt, Germany), friability (Erweka friabilator, model A3R, Frankfurt, Germany), anddisintegration time (Erweka, model ZT4, Heusenstamm, Germany) according to USP22tests/2010. The diametral compression test defined by Fell and Newton [22] w<strong>as</strong> used todetermine <strong>the</strong> tensile strength T, using <strong>the</strong> <strong>for</strong>mula:T2P Dt(3.2)Where P (kP) is <strong>the</strong> applied stress, D (cm) is <strong>the</strong> diameter <strong>of</strong> <strong>the</strong> tablet, and t (cm) is <strong>the</strong> tabletthickness. Three tablets from each batch were subjected to tensile strength determination.The solid fraction (SF) and porosity ( ) were calculated b<strong>as</strong>ed on <strong>the</strong> true density ( true ), tabletvolume (v), and tablet weight (Wt) <strong>as</strong> below [23] :SFw t true(3.3) 1SF(3.4)2.7 In vitro tablet disintegration testThe tablet disintegration test w<strong>as</strong> carried out using a TA-XDPlus texture analyzer (StableMicro Systems) similar to a recent study [24] . The apparatus w<strong>as</strong> calibrated with a 5 kg load celland fitted with a flat-bottomed cylindrical stainless steel probe (P/25, 12mm in diameter and25mm in height). In summary, <strong>the</strong> completely dry tablet is placed on <strong>the</strong> per<strong>for</strong>ated grid and it isnot in contact with <strong>the</strong> disintegration medium. The probe descends until a trigger <strong>for</strong>ce isdetected where it gets in contact with <strong>the</strong> tablet placed on <strong>the</strong> grid and pushes <strong>the</strong> whole systemdownwards. The tablet <strong>the</strong>n touches <strong>the</strong> medium and starts disintegrating. At this point, <strong>the</strong> TAapparatus is set to maintain a predetermined nominal <strong>for</strong>ce (50 g) <strong>for</strong> a given period <strong>of</strong> time (60s). For all <strong>the</strong> disintegration studies artificial saliva (pH 5.8) w<strong>as</strong> used <strong>as</strong> a solvent medium inorder to simulate oral disintegration.2.8 In vivo tablet disintegration and bitterness evaluationIn vivo disintegration and t<strong>as</strong>te m<strong>as</strong>king evaluation w<strong>as</strong> per<strong>for</strong>med on 10 healthy humanvolunteers [25, 26] from whom in<strong>for</strong>med consent w<strong>as</strong> first obtained (approved by <strong>the</strong> Ethics44 | P a g e

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