1.4 Gel

Question 1

What are gelling agent (Carbomers) ?

Answer 1

-high molecular weight water-soluble polymers of acrylic acid cross-linked with allyl ethers of sucrose and pentaerythritol
-viscosity depends on polymeric composition
-concentrations at 0.5% to 2.0% in water

Question 2

What is the classification of gels ?

Answer 2

-single-phase gels
-two-phase gels

Question 3

Describe single-phase gel

Answer 3

-macromolecules are uniformly distributed throughout the liquid with no boundaries between dispersed macromolecules and liquid
-involve organics

Question 4

Describe two-phase gels

Answer 4

-gel mass consists of floccules of small distinct particles
-involve inorganic
-eg: bentonite magma

Question 5

What are the preparations of gels ?

Answer 5

-gels formulated to contain a drug substance, solvents,propylene glycol, antimicrobial preservatives
-care should be taken to ensure uniformity of the APIs by dispersing by vigorous mixing or by shaking when preparation is less viscous
-eg: methylparaben, propylparaben

Question 6

What is the example of gel formulation ?

Answer 6

Androgel

Question 7

What is Androgel and it’s functions ?

Answer 7

Androgen (clear, colorless, containing testosterone) is…
-for Topical use
-indicated for replacement therapy in adult males for conditions associated with deficiency / absence of endogenous testosterone

Question 8

How are gels packaged ?

Answer 8

-stored in a tight container
-avoid freezing gels