Liquid Dosage Form-[Suspension]

Proverbs 16:3

Dispersion System

These are biphasic liquid dosage forms in which the particle size of the dispersed phase ranges from 0.5 to 10 micrometers (µm).

0.5 to 10 micrometers (µm).

DISPERSION SYSTEM are biphasic liquid dosage forms in which the particle size of the dispersed phase ranges from _____ micrometers (µm).

1. Suspensions

2. Emulsions

Types of Dispersion System [2]

Suspension

A liquid dosage form containing FINELY DIVIDED drug particles distributed somewhat uniformly throughout a vehicle in which the drug exhibits a MINIMUM degree of solubility.

• Appropriate for suspension preparation

• That available for milling

• Mixing equipment

• Particle size control

• Wetting

• Sedimentation

• Brownian movement

• Electro kinetic Properties

• Aggregation

Theoretical Consideration of Suspension [9]

Flocculated

Loose aggregates of particles (granule-like)

a. Deflocculated

b. Flocculated

Deflocculated

Particles are SEPARATE ENTITIES (powder-like)

a. Deflocculated

b. Flocculated

Flocculated

Faster sedimentation rate

a. Deflocculated

b. Flocculated

Deflocculated

Slower sedimentation rate

a. Deflocculated

b. Flocculated

Flocculated

Faster sediment formation

a. Deflocculated

b. Flocculated

Deflocculated

Slower sediment formation

a. Deflocculated

b. Flocculated

Flocculated

Absent (-) Hard cake formation

a. Deflocculated

b. Flocculated

Deflocculated

Present (+) Hard cake formation

a. Deflocculated

b. Flocculated

Flocculated

Appearance: Unsightly

a. Deflocculated

b. Flocculated

Deflocculated

Appearance: Cloudy appearance

a. Deflocculated

b. Flocculated

Flocculated

Appearance : Clear supernatant liquid + distinct sediment layer

a. Deflocculated

b. Flocculated

Deflocculated

Appearance : uniform dispersion

a. Deflocculated

b. Flocculated

strong affinity

[Theoretical Considerations in the Manufacture of Suspensions]

When a _____ [STRONG/WEAK AFFINITY] exists between a solid and liquid, the liquid will easily FORM A FILM over the surface of the solid.

film

[Theoretical Considerations in the Manufacture of Suspensions]

When a STRONG AFFINITY exists between a solid and a liquid, the liquid will easily form a ______over the surface of the solid.

weak affinity

[Theoretical Considerations in the Manufacture of Suspensions]

When there is ______ [STRONG/WEAK AFFINITY], the liquid has difficulty in displacing AIR surrounding the liquid due to an ANGLE OF CONTACT.

Air

[Theoretical Considerations in the Manufacture of Suspensions]

When there is a WEAK AFFINITY, the liquid has difficulty of displacing the ______ surrounding the solid due to an ANGLE OF CONTACT.

angle of contact

[Theoretical Considerations in the Manufacture of Suspensions]

When there is a WEAK AFFINITY, the liquid has difficulty displacing the air surrounding the solid due to an ________.

Hydrophilic Substances

Are easily wet by WATER or other POLAR LIQUIDS.

a. Hydrophilic Substances

b. Hydrophobic Substances

Hydrophobic Substances

Repel water, but are easily wetted by nonpolar liquids.

a. Hydrophilic Substances

b. Hydrophobic Substances

Hydrophobic Substances

Are easily wetted by nonpolar liquids.

a. Hydrophilic Substances

b. Hydrophobic Substances

Hydrophilic Substances

May greatly INCREASE the VISCOSITY of an aqueous suspension.

a. Hydrophilic Substances

b. Hydrophobic Substances

Hydrophobic Substances

Do NOT ALTER the VISCOSITY of an aqueous suspension.

a. Hydrophilic Substances

b. Hydrophobic Substances

Hydrophilic Substances

Can be incorporated into suspensions without a need for a wetting agent.

a. Hydrophilic Substances

b. Hydrophobic Substances

Hydrophobic Substances

Are difficult to disperse and frequently float on the surface of the liquid, due to poor wetting of particles.

a. Hydrophilic Substances

b. Hydrophobic Substances

Poor wetting

HYDROPHOBIC SUBSTANCES are difficult to disperse and frequently float on the surface of the liquid, due to_______ of particles?

a. Poor wetting

b. Better wetting

1. First, add the soluble components to the diluent, mix them, and disperse them into the carrier.

2. Wetting agents can be used to disperse the carrier.

3. Grind coarse drug particles into a suspension with the required degree of dispersion within a dispersion medium.

4. This method is closely related to the hydrophilicity of the drugs.

Methods of Developing Pharmaceutical Suspension and their Principles

• Dispersion Method [4]

Dispersion method

This method is closely related to the hydrophilicity of the drugs.

a. Dispersion method

b. Condensation method

1. Dissolve the drug in a BENIGN SOLVENT to prepare a hot saturated solution.

2. Add this solution to another cooled poor solvent under rapid stirring, causing the drug to rapidly crystallize and form particles below 10 μm (accounting for 80%–90%).

3. Then, suspend the formed particles in a dispersion medium to obtain the FINAL SUSPENSION.

Methods of Developing Pharmaceutical Suspension and their Principles

• Condensation Method [3]

Condensation method

[Dispersion method/Condensation method]

When preparing, attention should be paid to the conditions for chemical reactions that generate precipitates, in order to obtain uniform and fine new precipitates.

a. Dispersion method

b. Condensation method

Tap water

This type of water CANNOT BE USED in manufacturing pharmaceutical suspension because it contains many MICROORGANISM , so a WATER TREATMENT system is needed.

Miller

For particle size reduction.

a. Mixer

b. Miller

Mixer

For blending ingredients to become a SLURRY (concentrated mixture)

a. Mixer

b. Miller

Horizontal Ribbon Mixer

A machine that processes solid or liquid materials mechanically, physically, and chemically to produce a uniform slurry.

Homogenizer Vacuum Emulsifying Mixer

Device that can also play a mixing role, effectively mixing different pharmaceutical suspensions and other liquids, making the mixed substances uniform and free of any lumps.

Colloid Mill

An ultrafine grinding equipment whose main function is to:

1. Disperse solid or liquid materials into extremely fine particles.

2. Mix other materials in the liquid to achieve uniform dispersion.

Rotary Filter

Used for solid-liquid separation of various suspensions, with relatively HIGH FILTRATION accuracy.

Stainless Steel Tank

_________-

• This is made of high-quality stainless steel material, which has good corrosion resistance.

• This is suitable for various acidic and alkaline liquids.
  

jacketed steam system

Stainless Steel Tank is a machine that includes a _____ system

Wetting agents

[Formulation of Suspension]

They are added to DISPERSE SOLIDS in the continuous liquid phase.

Flocculating agents

[Formulation of Suspension]

They are added to FLOCCULATE the drug particles.

Thickening agents

[Formulation of Suspension]

They are added to INCREASE the VISCOSITY of the suspension.

Buffers

[Formulation of Suspension]

They are added to stabilize the suspension to a desired pH range.

Osmotic agents

[Formulation of Suspension]

They are added to adjust OSMOTIC PRESSURE comparable to biological fluid.

Coloring agents

[Formulation of Suspension]

They are added to impart desired COLOR and improve ELEGANCE.

Preservatives

[Formulation of Suspension]
They are added to prevent microbial growth.

External Liquid Vehicle

[Formulation of Suspension]

They are added to construct the STRUCTURE of the FINAL SUSPENSION.

1. Reduce particle size

2. Disperse the suspending agent slowly into the vehicle while mixing

3. Disperse the drug slowly into the vehicle along with the wetting agent while mixing

4. Add the other ingredients into the mixture

5. Homogenize the final mixture

General Steps in Manufacturing Suspension [5]

General Steps in Manufacturing Suspension [Diagram]