Commercial Manufacturing Pharmaceutical Unit Processes

Question 1

Mixing is putting together of ingredients in _____ with more or less thorough dispersion of the constituted elements among one another

Objective:

Answer 1

One mass or assemblage

To obtain dosage units of the SAME QUANTITY of drug substance

Question 2

Fluids mixing mechanisms
Involves the movement of a relatively LARGE PORTION of the fluid being mixed from one location to another

Makes use of _____

_____ which move adjacent volumes of the fluid in _____

Must result in a _____ of the various portions of the fluid being mixed to be considered effective

Answer 2

Bulk transport

Paddles, Revolving blades

Shuffling- 3D directions

Rearrangement or permutation

Question 3

Fluids mixing mechanisms
It is the direct result of TURBULENT fluid flow which is the _____ of fluid velocity at any given point within the system

Meaning of TURBULENT

Answer 3

Turbulent mixing

Random fluctuations

Moving in an irregular or violent way

Question 4

Fluids mixing mechanisms
Based on STREAMLINE or LAMINAR flow

Encountered in processing _____, but also stirring that is gentle adjacent to stationary surfaces in a vessel

Achieved by mixers which _____ the fluid being mixed

Answer 4

Laminar mixing

Highly viscous liquids

Stretches and folds

Question 5

Fluids mixing mechanisms
Involves DIFFUSION which results from _____ of the molecules

Usually performed with LAMINAR mixing to _____ at the interfaces between the fluid layers

Answer 5

Molecular diffusion

Thermal motion

Reduce sharp discontinuities

Question 6

Equipment

Used when material to be mixed is LIMITED IN VOLUME and can be conveniently contained in a suitable mixture

System consist of two primary component

Answer 6

Batch mixing

Tank or container to hold while mixing
A means of supplying energy for rapid mixing

Question 7

An equipment of batch mixing

It produce RADIAL flow

It produce AXIAL and TANGENTIAL flow

Most EFFICIENT when they can run at high speed in liquids of relatively low viscosity

Answer 7

Impellers
Propeller

Turbines

Propellers

Question 8

An equipment of batch mixing
Usually arranged in a way that allows the BUOYANCY of the bubbles to lift the liquid from the bottom to the top of the mixing vessel

Used in liquids of

Answer 8

Air jets

Low viscosity, non-foaming, unreactive with the gas employed and non-volatile

Question 9

An equipment of batch mixing
Fluids are pumped through NOZZLES arranged to permit GOOD CIRCULATION of material throughout the tank

Generates _____ in the direction of their axes, does not generate _____

Answer 9

Fluids jets

Turbulent flow, tangential flow

Pump fluid itself

Question 10

This produces an UNINTERRUPTED supply of freshly mixed materials

Desirable in handling _____ of material

The feed rate within the tube is carefully controlled and should be uniform via an _____

If the rate is difficult to control what is used

Complex arrays of interconnected tanks can be used for _____

Answer 10

Continuous mixing

Very large volumes

Exact metering device

Tank

Mixing

Question 11

Continuous mixing is accomplished through the use of

Answer 11

Tube or pipe
Chamber

Question 12

Factors to consider in mixer selection

Answer 12

Physical properties of materials (density, viscosity, miscibility)
Economic considerations (time required, powder expenditure)
Cost of equipment and maintenance

Question 13

Selection of equipment depends on VISCOSITY and DENSITY of the fluid

A. Best mixed by method that generates a HIGH DEGREE OF TURBULENCE and circulate the entire mass of material

B. Mixed by turbines of FLAT BLADE design

Answer 13

Monophase systems

A. Low viscosity
B. High viscosity

Question 14

Composed of several liquid or solid phases

Involves the SUBDIVISION or DEAGGREGATION of one or more of the passes present with subsequent dispersal throughout the mass of material to be mixed

Answer 14

Polyphase systems

Question 15

Polyphase systems
Mixing requires the subdivision of one of the phases into GLOBULES which are successively reduced in size and are then distributed throughout the bulk of the liquid

Selection of equipment depends on _____
A. _____: requires HIGH SHEAR rates produces by passing the fluid under HIGH PRESSURE through small orifices
B. _____: dispersed by the shearing action of two surface in CLOSE PROXIMITY and moving at DIFFERENT VELOCITIES
- Achieved in _____

Answer 15

Immiscible liquids

Viscosity
A. Low (emulsions)
B. High (Ointments)
-paddle mixers

Question 16

HIGH viscosity immiscible liquids are relatively efficient since they

Answer 16

Generate SUFFICIENT shear to reduce globule size
Induce SUFFICIENT circulation of material to ensure UNIFORM dispersion throughout the completed mixture

Question 17

Polyphase systems
Mixing depends on SEPARATION OF AGGREGATES into primary particles and the distribution of these particles throughout the fluid

Mixing is done with the help of _____ which generate shear forces of sufficient intensity to _____

Answer 17

Finely-divided solids in liquids

High speed turbines, disrupt aggregates

Question 18

Finely-divided solids in liquids
A. _____: efficient in DEAGGREGATION of solids but are typically inefficient in distributing the articles uniformly throughout the entire mass
B. _____: composed of ABRASION-RESISTANT ROLLERS

Answer 18

A. Muller mixers
B. Roller mixers

Question 19

Batch mixing
_____: consists of a container of one of several GEOMETRIC forms

The resulting motion is accentuated by means of _____ or simply by virus of the shape of the container

Answer 19

Tumbling mixers

Baffles: restrain the flow of prevent spreading sound or light

Question 20

Efficiency of tumbling mixers depend on the _____

A. _____: not produce the desired intense tumbling or cascade
B. _____: tend to produce CENTRIFUGAL FORCES sufficient to hold the powder to the sides

Optimum rate of rotation ______

Answer 20

Speed of rotation
A. Too slow
B. Too rapid

30-100 rpm

Question 21

Batch mixing tumbling mixers
Takes the form of a cylinder that has been cut in half approximately a 45 degree angle with it’s long axis and then rejoined to form a V SHAPE

The material _____ which causes the final blend to be very HOMOGENOUS

Answer 21

Twin-shell blender or V blender

Question 22

Batch mixing
Consists of a container to hold the material and moving crews, paddles or blades to bring about mixing

Does not depend entirely on _____; useful in mixing solids that have been _____
A. _____: consists of a HORIZONTAL cylindric tank.
B. _____: powders are lifted by a centrally located VERTICAL screw and allowed to cascade to the bottom of the tank

Answer 22

Stationary mixers

Gravity, wetted (sticky or plastic state)

A. Ribbon blender
B. Helical flight mixer

Question 23

Large mixers have _____ in composition than small mixers

Answer 23

Greater variation

Question 24

Metered quantities of the powders or granules are passed through a device that reduces both the SCALE and INTENSITY of segregation, usually by impact or a shearing action

May be transferred directly to capsule filling or tablet machines

Answer 24

Continuous mixing