DDS LAB - PREP 12: Eucalyptus Oil Emulsion

Preservatives

This is required by the USP for all emulsions as they are highly prone to microbial contamination and growth, and may also be adversely affected by other physical and chemical alterations

Eucalyptus Oil Emulsion (Non-official)

Official Title

Expectorant

Category

Expectorant for Chronic Bronchitis

Use/s

Types of Emulsion Instabilities

• Creaming

• Sedimentation

• Coalescence (Cracking or Breaking)

• Flocculation

• Phase Inversion

Creaming

It occurs when the dispersed phase of the emulsion rises or floats to the surface, forming an uneven distribution.

Sedimentation

It occurs when the dispersed phase of the emulsion sinks or moves towards the bottom, also forming an uneven distribution.

Coalescence (Cracking or Breaking)

• It occurs when the internal phase droplets form an irreversible coalescence.

• It is the separation of the dispersed phase and dispersion medium.

Flocculation

• Its occurrence is due to attractive and retractive force between molecules.

• It is when aggregation of the dispersed droplets happen upon vigorous agitation and shaking.

Phase Inversion

It is the process of changing the emulsion type from O/W to W/O and vise versa.

Creaming can be reduced by decreasing the particle size and the density particles  difference, increasing the viscosity of the dispersion medium, and storing at lower temperatures.

Considering the qualitative application of Stokes’ Law, how can creaming be reduced?

Factors that can Cause Cracking of Emulsion

• Freezing

• Excess Alcohol

• Excess Electrolytes

Considerations to Preserve Stability of Emulsions

• Compatibility

• Solubility

• Broad-spectrum antimicrobial activity

White, milky opaque, homogenous liquid

Acceptance Criteria:
Appearance

4.5 - 5.5

Acceptance Criteria:

pH

O/W: Remain Stable

W/O: Break (due to incompatibility with water)

Dilution Test Results

O/W: Lamp will glow

W/O: Lamp will NOT glow

Conductivity Test Results

O/W: Colorless globules against a colored background

W/O: Colored globules against a colorless background

Dye-Solubility Test Results

O/W: Turns Pink

W/O: No Color Change

Cobalt (II) Test Results

O/W: Spotty Fluorescence

W/O: Fluorescence all throughout

Fluorescence Test Results

Preserve in a well-filled, tight container at room temperature

Packaging Requirement