Posts tagged with "Friction"



01. September 2018
Flow properties of microcrystalline cellulose (MCC) excipients, Avicel PH 101 and Avicel PH 102 have been compared by using Brookfield PFT. Afterwards, the effect of hydrophobic Silica R972 as glidant has been tested on both the excipients. Hand blending is done by mixing MCCs with hydrophobic silica R972 vigorously by SAC as an underlined basis for 10 minutes and the flow properties tests are performed. During the flow function test “as received” Avicel PH 102 shows better flow function...

Comparative evaluation of powder flow parameters with reference to particle size and shape
29. May 2018
Powder flow is critical to the success of various pharmaceutical processes such as tableting and capsule filling. Despite a plethora of flow characterisation techniques and parameters available, powder flow still remains to be a not well understood subject. Inter-relationships between the various powder flow parameters in particular have not been well established. Furthermore, while it is known that particle size and shape are important determinants of powder flow, their relative impact on...

Graph with results of predicted versus measured tablet ejection forces
09. April 2018
Pharmaceutical powders can exhibit markedly different tablet ejection forces. The purpose of this study is to understand the factors leading to the variability of the tablet ejection force and its sensitivity to lubrication. The study showed that the tablet ejection force is mainly governed by 1) tablet diameter and thickness, 2) compact-die wall friction coefficient, and 3) residual die wall stress upon ejection; the latter was further controlled by the maximum compression pressure, as well as...

20. April 2017
Abstract The purpose of this study is to demonstrate that the flow function (FFc) of pharmaceutical powders, as measured by rotational shear cell, is predominantly governed by cohesion, but not friction coefficients. Driven by an earlier report showing an inverse correlation between FFc and the cohesion divided by the corresponding pre-consolidation stress [Wang et al. 2016. Powder Tech. 294:105-112], we performed analysis on a large dataset containing 1130 measurements from a ring shear...
05. April 2017
Abstract We investigated the effectiveness of using Carr’s flowability index (FI) and practical angle of internal friction (Φ) as indexes for setting the target Mg-St mixing time needed for preparing tablets with the target physical properties. We used FI as a measure of flowability under non-loaded conditions, and Φ as a measure of flowability under loaded conditions for pharmaceutical powders undergoing direct compression with varying concentrations of Mg-St and mixing times. We evaluated...
04. September 2016
Abstract: This paper focuses on the characterization of the tabletting process and analysis one of the most common pharmaceutical excipients MCC Avicel PH102 by Heckel, Kawakita, Cooper-Eaton and Adams compaction equations. Experimental material was determined by measuring its parameters as particle size distribution, angle of wall friction and flow properties and for more detailed characteristics of the material particles, microscopy images of the powder before and after compressing were...
15. August 2016
Abstract The methods used for flow characterization of a powder mass include the angle of repose (AOR), Carr index (CI), and powder flow tester (PFT). The use of nanosilica as a flow modifier (glidant) is very common in industry. This study aims to compare the glidant effect of hydrophobic and hydrophilic silica on a poorly flowable active pharmaceutical ingredient (ibuprofen) by different flow characterization techniques. Different percentages (0.5, 1.0, and 2.0 wt%) of both types of mixed...
09. March 2016
Abstract: Lubrication plays a key role in successful manufacturing of pharmaceutical solid dosage forms; lubricants are essential ingredients in robust formulations to achieve this. Although many failures in pharmaceutical manufacturing operations are caused by issues related to lubrication, in general, lubricants do not gain adequate attention in the development of pharmaceutical formulations. In this paper, the fundamental background on lubrication is introduced, in which the relationships...