How glidant increases flow properties of powder?

How glidant increases flow properties of powder?

The flow Property of powder is increased by adding glidant such as talc, magnesium stearate, and starch. Flow property is measured by angle of repose. It is the maximum angle between the free standing surface of powder and horizontal plane. The objective of the glidant is to increase the flow property of powder.

What is a good Hausner ratio?

Bulk density may be used as an indication of flow properties. The ratio of tapped density W/V50 to fluffy density (W/V0 g/ml) is known as the Hausner ratio. A good flow is indicated by a Hausner ratio greater than 1.25, and a poor flow may have a value of 1.5.

What is flow rate of powder?

Powder flow, also known as flowability, is defined as the relative movement of a bulk of particles among neighboring particles or along the container wall surface. In other words, powder flowability refers to the ability of a powder to flow in a desired manner in a specific piece of equipment…

What is flow properties of powder?

Powder properties affect the packing dynamics/efficiency and flowability. Few such flow properties and techniques are powder spreadability, dynamic and static angle of repose, packing, flowability, and electrostatic charge.

How is Carr’s index calculated?

The Carr index (also: Carr’s index or Carr’s Compressibility Index) is an indication of the compressibility of a powder. It is named after the scientist Ralph J. In a free-flowing powder, the bulk density and tapped density would be close in value, therefore, the Carr index would be small.

Why is lubricant added in the last step?

Lubricants are added to the powder mixture prior to the tabletting step to ensure that the tablet is ejected properly from the press. The addition of lubricants also affects tablet properties and can affect the behavior of the powder mixture.

How is flow rate of powder measured?

Some of the most commonly applied methods to measure the flow of powders include: density indices, such as the Carr index and Hausner ratio, powder avalanching, the angle of repose (AOR), flow through an orifice, powder rheometry and shear cell testing.

What is Carr’s index formula?

The Carr index (also: Carr’s index or Carr’s Compressibility Index) is an indication of the compressibility of a powder. It is named after the scientist Ralph J. Carr, Jr. The Carr index is frequently used in pharmaceutics as an indication of the compresiblity of a powder.

How do you calculate flow rate of powder?

The rates of flow of the powders are given by the expression where W is the flow rate in g min−1, Do is the orifice diameter in cm, ρ is the particle density in g cm−3, g is the gravitational constant, and A and n are numerical terms which depend on temperature and particle size.

How do you increase powder flow?

Granulation is a common technique to help to improve product flow and achieve mass flow. Powder granulation can reduce inconsistency in particle size, reduce “fines” (very small particles), control dust, and reduce the tendency of powders to segregate.

What is the range of Carr’s index to call the powder flow is excellent?

Powder Properties

Carr’s compressibility index (%) Hausner ratio Description of flow
<10 1.00–1.11 Excellent
11–15 1.12–1.18 Good
16–20 1.19–1.25 Fair
21–25 1.26–1.34 Passable

How is glidant used to improve powder flow?

The two-step operation of glidant mixing enhanced powder flow of the high-dose direct compression formulation compared with the one-step operation. The two-step operation eliminates the bottleneck of powder flow and allows direct compression to be more worth applying for formulation and process development trials.

What’s the difference between boundary lubricant and glidant?

Boundary lubricants are more commonly used over fluid lubricants [7]. On the other hand, a glidant’s effect is due to a counter-action to factors resulting in poor flowability of powders. Besides, glidant increases powder flow properties by correcting surface irregularity, reducing interparticular friction as well as decreasing surface charge.

Why do we use glidants in capsules and tablets?

Lubricants are substances that we use in tablet and capsule formulations in order to reduce the friction. Glidants are substances that we use to increase the flowability of a powder. That means it promotes the flow of the tablet granules (or the powder).

Which is the best flow characterization method for glidants?

In addition, it was confirmed that the flowability of glidant with a narrow particle size distribution leads to good flow conditions. This study reveals how choice of flow characterization method can play a key role in multi-factorial determination of the glidant type.