Experiment 8 - 9 Flashcards
Thick, viscid, adhesive liquid dispersion of gum in water.
MUCILAGES
Signs of decomposition MUCILAGES
▪ Formation of sediments or precipitates
▪ Mold growth or microbial growth
▪ Decrease viscosity
▪ Color change
▪ Gas formulation
MUCILAGES Pharmaceutical uses
▪ Suspending agent
▪ Tablet Binders
▪ Emulsifying agent
▪ Diluting Agent
MUCILAGES Therapeutic uses
▪ Demulcent
▪ Protective
▪ Bulk Laxatives
Synthetic mucilage
– Polyvinyl alcohol
– Methylcellulose
– Carboxymethylcellulose
Increase the viscosity of water by binding water molecules, thus limiting their mobility and fluidity.
HYDROPHILLIC COLLOIDS
Viscosity is _________ to the concentration of the colloid.
proportional
ACACIA GUM aka
Gum arabic
ACACIA GUM source
The dried gummy exudate from the stems and branches
Acacia senegal, Family Leguminosae (Fabaceae)
Acacia trees are tapped by making a __________ in the bark and peeling it both above and below the cut, thus exposing an area of cambium 2 to 3 feet in length and 2 to 3 feet in breadth.
TRANSVERSE INCISION
The formation of the gum maybe caused by
bacterial action or by action of a ferment.
ACACIA GUM Physical properties
▪ Spheroidal tears or angular fragments
▪ Up to 32 mm in diameter
▪ White to yellowish-white color
▪ Translucent or somewhat opaque
▪ Very brittle, almost brittle,
▪ Almost odorless
▪ Soluble
ACACIA GUM Chemical properties
▪ Consists principally of arabin=
▪ 12-15% water
▪ Enzymes
ACACIA GUM Uses
Emulsifying agent
Suspending Agent
Adhesive and Binder
Demulcent
Emollient
ACACIA GUM Incompatibilities
- Alcohol and alcoholic solutions precipitate acacia
- Heavy Metals
- Borax
- Contains peroxidase which acts as an oxidizing agent
- React with alkaloids
- Hydrolized by dilute mineral acid
TRAGACANTH GUM aka
Hog Gum, Goat’s thorn
TRAGACANTH GUM sources
The dried, gummy exudate
Astragalus gummifer, Family Leguminosae (Fabacea)
ACACIA GUM origin
Sudan
Senegal
TRAGACANTH GUM origin
Asia Minor,
Iran, Syria,
Soviet Union,
Greece.
TRAGACANTH GUM Physical properties
Flattened, lamellated, frequently curved fragments or straight or spirally twisted linear pieces
0.5 to .25 mm in thickness
white to weak yellow in color
Odorless
Insipid, mucilaginous taste
Soluble
TRAGACANTH GUM Chemical properties
Contains 60 to 70% of basorin=
30% Tragacanthin
TRAGACANTH GUM Uses
- Emulsifying Agent
- Demulcent
- Basis for pharmaceutical jellies
- Excipient in pills
- Suspending Agents
- Protective
TRAGACANTH GUM Incompatibilities
Precipitated by alcohol
Viscosity is reduced by acid, alkali, sodium chloride and if the mucilage is heated.
A two-phase system in which one liquid is dispersed in the form of small globules throughout another liquid in which it is immiscible.
Emulsions
Emulsions phase
- Internal Phase
- External or Continuous Phase
- Emulsifying Agent
Types of Emulsions
- Oil-in-Water Emulsions (o/w)
- Water-in-oil Emulsions (w/o)
emulsions with an oleaginous internal phase and an aqueous external phase.
Oil-in-Water Emulsions (o/w)
emulsions having an aqueous internal phase and an oleaginous external phase
Water-in-oil Emulsions (w/o)
Purpose of Emulsification
- to prepare relatively stable and homogenous mixtures of two immiscible liquids
- Permits administration of a liquid drug in the form of minute globules rather than in bulk
- The oil is more digestible and more readily absorbed
- Decrease the irritating effects of medicinal substances
- Emollient / softens the tissue and skin
Preparation Of Emulsions
- Selection of the emulsifying agent
- Method employed for preparing
Emulsifying Agents
– agent to promote emulsification
– maintain the stability of the emulsion for the intended shelf life of the product
– Must be compatible with the other formulating ingredients
– Must not interfere with the stability or efficacy
– Should be stable and not deteriorate in the preparation
– Should be non-toxic
– Should possess little odor, taste or color
Emulsifying Agents and Stabilizers types
- Carbohydrate Materials
- Protein substances
- High Molecular Weight Alcohols
- Wetting Agents
- Finely divided solids
- Antioxidants
- Humectant
Naturally occurring agents; form hydrophilic colloids which when added to water; produce o/w emulsions
Carbohydrate Materials
Produce o/w emulsions
Protein substances
Employed primarily as thickening agents and stabilizers for o/w emulsions
High Molecular Weight Alcohols
Wetting Agents
Anionic
Cationic
Nonionic
Generally form o/w emulsions
Finely divided solids
each emulsifying agent has a __________ portion and a __________ portion, with one or the other being more or less predominant.
hydrophilic; lipophilic
A method which has been devised whereby the emulsifying or surface-active agents may be categorized on the basis of their chemical makeup as to their hydrophil–lipophil balance,
HLB SYSTEM
Methods of Emulsion Preparation
Continental Method
English Method
Bottle Method
Auxiliary Method
In Situ Soap Method
Continental Ratio
1G + 4O + 2W
English Ratio
1G + 2W + 4O
Bottle Ratio
2O/2W + 1G
Microemulsion
Biphasic o/w & surfactant
Growth of one emulsion droplet at the expense of a smaller one
Ostwald ripening
Bentonite comes from _________ sources
Volcanic
Solution or mixtures of various substances in oil, alcoholic solution of soup or emulsion, intended for external application
Liniments
Vehicles of liniments intended generally for rubefacients, counterirritant, mildly astringent and penetrating effects
Alcoholic
Vehicles used for liniments with protective coating function
Oleaginous
Liniments uses
> Used to relieve itching
Cause biological tissues to contract
Softens skin or treat dry skin
Relieves pain
Rubefacient
Counterirritant
Gels in nature
Thixotropic
Mucilages Decomposition remedy
Don’t use in large quantities
Use them immediately
Add preservative
Arabin is a complex of
Calcium
Magnesium
Potassium Salt
Polysaccharides in acacia
L-arabinose
D-galactose
D-gluconic acid
L-rhamnose
Acacia gum dispersion in water
35%
Tragacanth gum dispersion in water
6%
Basorin is a complex
polymethoxylated acid
Tragacanthin is ___________ product of gum
demethoxylated
polymethoxylated acid makes tragacanth
Viscous and water soluble
Tragacanth pros against acacia
Less prone to decomposition
Resistant to hydrolysis
Prefered in acidic preparation
Causes the swelling when acacia is hydrolyzed
Polysaccharides
Acacia gum enzymes
Oxidase
Peroxidase
Pectinase
Acacia is completely soluble in ________ its weight
twice
tragacanth absorbs certain forms of liquid that swells into ____________
Adhesive paste
Emulsifying agent other names
Emulgent
Emulsifiers
Oil in water products
for solution
Water in oil product
lotion and creams
Carbohydrate Material
Agar (irish moss)
Acacia
Pectin
Microcrystalline cellulose,
lechitin
Carbohydrate material disadvantage
Prone to microbe attack
Protein substance
Egg yolk
Gelatin
Casein
Protein substances products
Mayonaise
Yogurt
Natural emulgents and stabilizers
Carbohydrate
Protein
High Molecular Weight Alcohol O/W
Stearyl
Cetyl
Glyceryl monostearate
High Molecular Weight Alcohol W/O
Cholesterol
Wetting agent Anionic
Sodium lauryl sulfate
Wetting agent Cationic
Quats(Quaternary Ammonium Compound)
Benzal C.
Quats are also used as
Preservative
Wetting agent Non ionic
Tweens and Spans
Finely divided solids clays
Bentonite
Veegum
Magnesium Hydroxide
Aluminum Hydroxide
Antioxidant
BHT = Butylated Hydroxy toluene
BHA = Butylated Hydroxy anisole
Vitamin E = Tocopherol
Humectant
Glycerin
PEG
MO
An emulsion prepared by either wet gum or dry gum method can generally be increased in quality by passing it through a hand homogenizer.
Auxiliary Method
Auxiliary Method reduces particle size to
5 mcm or less
Applied in soap making
In Situ Method
In Situ Method ingredients
Water
Alkali
Oil
Alkali in Soap making
Lye Sodium Hydroxide
Limewater Calcium Hydroxide
In Situ Method emulgent
Calcium oleate
Calcium Soap
Calamine liniment
Soft soap
Turpentine liniment
Thermodynamically stable, optically transparent isotropic mixtures of a biphasic o/w system stabilized with surfactants
Microemulsions
Microemulsions ADVANTAGES:
- More rapid and efficient oral absorption of drugs than through solid dosage forms
- Enhanced transdermal drug delivery through increased diffusion into the skin
- Unique potential application of microemulsions in the development of artificial RBC
completely breaks, i.e., the system separates into bulk oil and water phases, can result to cracking.
Coalescence
Surfactants of Microemulsion
Polysorbate 60 and 80
this is the term applied when the disperse phase coalesces and forms a separate
Cracking
the oil separates out, forming a layer on top of the emulsion,
Creaming
can be generally defined as the aggregation of droplets to give 3-D clusters without coalescence occurring.
Flocculation
sedimentation and coalescence of emulsified drops of the dispersed phase so that they will settle out of the carrier liquid;
Breaking
- this is the process when an oil-in-water emulsion changes to a water-in-oil emulsion or vice versa.
Phase inversion
For stability of an emulsion, the optimum range of concentration of dispersed phase is _______ of the total volume.
30–60%
Factors influencing the rate of separation
- Particle size of the dispersed phase
- Difference in density between the phases
- Viscosity of the external phase
To Increase Stability:
- The globule or the particle size should be reduced as fine as is practically possible
- Density difference between the internal and the external phases should be minimal
- Viscosity of the external phase should be reasonable high (thickeners)
Storage Requirements
- Should be protected from extremes cold and heat
- Protected from light, air and contaminating microorganisms
Cod Liver oil Emulsion use
Vitamin D and A Supplementation
Mineral Oil Emulsion use
Lubricant laxative
Eucalyptus Emulsion use
Pain reliever
Methyl salicylate emulsion
Temporary relief of muscle and joint pain
Turpentine Oil Emulsion use
Rheumatoid arthritis
