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Flashcards in milling and blending Deck (18)
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1

reason for size reduction

1) increase SA for reaction
2) improve extraction of active principles
3) improve dispersibility
4) allow better mixing or blending*
5) enable rapid dissolution*
6) preliminary process in preparation of productions *

* impt for solid dosage form

2

what affect size reduction

mechanical- type of equipment
fracture mechanics of particles
properties of material

3

advantage of wet grinding

1) eliminate dust
2) Easy to handle
3) use less energy
4) increase mill capacity

4

Disadavantage of wet grinding

1) increase wear of grinding medium
2) not application to soluble material
3) may need drying of product

5

size reduction process

1) fracture
2) abrasion

6

factors affecting size reduciton

1) friability range (brittleness)
2) toughness
3) abrasiveness
4) hygroscopicity
5) explosiveness
6) corrosiveness

7

Size reducion mechanism

1) impact (hammer)
2) compression (roller)
3) shear (knife edge)
4) attration

8

advantage of hammer mill

1) several models available, verticl and horizontal designs
2) medium to high shear applications
3) blades and screens are interchangeable
4) suitable for very hard materials

9

disadvantage of hammer mill

1) noisy and dusty
2) cannot plug feed
3) belt slip common due to load
4) high volume air generation, ventilation requirement
5) screen selection and installation complex and not scalable
6) sifting required after milling
7) temperature rise due to friction

10

cone mill hole for wet dispersion

square hole

11

round impeller in cone mill for ____--

Dry sizing

12

squareimpeller in cone mill for ____--

wet and dry sizing

13

micronization mill

vibratory ball mill
air jet mill
fluid energy mill

14

loading methods

1) always consistent
2) layering reduces the number of blend revolution
3) layer large volumes of exvipient or active
4) lubricants do not normally require layering and tend to improve flow properties and may help blend cohesive products

15

essential for excipients and base materials to be within reasonable specifications otherwise it could lead to differing blend parameters

essential for excipients and base materials to be within reasonable specifications otherwise it could lead to differing blend parameters

16

issues to consider when using vibration IBC

1) compaction
2) segregation
3) noise
4) IBC damage
5) weighing systems
6) dosing capability
7) production residue

17

blending critical parameter

1) number of revolution
2) % fill
3) loading method
4) sampling method
5) formulation


- simple scale up process
- contained process

18

NIR benefit

1) safe
2) no sampling error
3) real time information
4) multi ingredient uniformity
5) process understanding
6) process finger - printing for scale up
7) right first time
8) fast release of the blend - reduced cycle times