This document discusses gels and magmas. It defines gels as viscous semi-rigid sols formed from a solid dispersed phase within a liquid continuous phase. Gels are classified as single-phase or two-phase systems. Magmas are two-phase systems with larger particles that form a suspension. Common gelling agents and uses of gels in various dosage forms such as suppositories, capsules, and microbiological media are described. Methods for preparing magnesium hydroxide magma and bentonite magma are also outlined.

1. GELS &MAGMAS

2. BUSHRA KHAN
11742
INTRODUCTION

3. GELS
 Gels are an excellent formulation for several
routes of administration. They are useful as
liquid formulations in oral, topical, vaginal, and
rectal administration. Gels can be clear
formulations when all of the particles completely
dissolve in the dispersing medium.
A colloid in which the solid disperse phase
forms a network in combination with the fluid
continuous phase, resulting in a viscous semirigid
sol.

4. CLASSIFICATION OF GELS
GELS ARE CLASSIFIED AS
SINGLE PHASE GEL SYSTEM
TWO PHASE GEL SYSTEM

5. SINGLE-PHASE GEL
Single phase gel consist of organic
macromolecules distributed uniformly
throughout a liquid.
EXAMPLES:
 Carbomer ,
Tragacanth

6. TWO PHASE GEL:
Gels that contain small, descrete
particles, Are thixotropic (semisolid
on standing but liquid when shaken)
EXAMPLE:
Alluminium hydroxide

7. WAJIHA RAZA
11807

8. TYPES OF GELS
THERE ARE THREE TYPES OF GELS:
1. HYDROGELS
2. XEROGELS
3. ORGANOGELS

10. CLOBETASOL PROPIONATE-
TERMOVATE GEL
DERMATOLOGIC: ANTIPRURITIC

11. VOLTARENGEL
The standard recommended Voltaren
Gel dosage for treating osteoarthritis

12. ACITIC ACID-ACI-JEL
USED:
VAGINAL: RESTORATION AND
MAINTENANCE OF ACIDITY.

13. MADIHA AHMED
11761

14. GELLING AGENT
Gelling agent are material used to
thicken & stabilize liquid solutions. They
dissolve in the liquid as colloid mixture
that forms an internal structure giving
the resulting gel an appearance of a solid
matter.

15. COMMON GELLINGAGENTS ARE:
 Acacia
 Pectin
 Strarch
 Tragacanth
 Xanthan gum
 Alginic acid (seaweed)
 Animal/vegatable fats: lard, cocoa butter
 Gelatin
 Bentonite, veegum (magnesium aluminum silicate)
 Carboxymethylcellulose (CMC) and other cellulose derivatives
 Carbomer resins (carbopols)
 Colloidal silicon dioxide
 Polyvinyl alcohol (PVA)
 Petrolatum, mineral oil/polyethylene gel.

16. ROUTES OF ADMINISTRATION

17. HIRA ARSHAD
11752
JAVERIA NAMEEM
11757

18. MAGMA
Two phase systems with large particle size or
floccules of small distinct particles are called
“MAGMA”. It is commonly known as Milk
Magnesia.
EXAMPLE:
 BENTONITE MAGMA

19. METHOD OF PREPRATION
Method of Preparations:
There are two methods of preparations:
(a) Hydration method and
(b) Hydration and Precipitation method.

20. HYDRATION METHOD:
Light magnesium oxide (MgO) is hydrated
with water to produce magnesium hydroxide
[Mg (OH)2].
MgO + H2O ® Mg(OH)2.
This method is followed by industries and in
Milk of Magnesia USP.

21. Hydration and Precipitation method:
A solution of sodium hydroxide (NaOH) is
triturated with light magnesium oxide to form
a smooth cream. It is diluted with water.
MgSO4 + 2NaOH = Mg(OH)2¯ + Na2CO3.
MgO + H2O = Mg(OH)2¯
Precipitation formed
The precipitation is mixed with chloroform
water to give the final preparation.

22. PREPARATION OF BENTONITE MAGMA

23. IMPORTANCE OF MAGMAS AND GELS
IN DOSAGE FORM
Glycogelation gels are frequently used as a
basis for medicated pastilles. They are also
used in the formulation of some
suppositories. E.g. Glycerin suppositories BP.
Gelatin gels are employed in the
preparation of hard and soft capsules that
may be used to mask the unpleasant tastes
of solid and liquids.

24. IN MICROBIOLOGICAL MEDIA:-
Agar and gelatin gels are used
as solid media for the culture
of micro-organism.

25. AS A LUBRICATING AGENT :-
Gels also used as a lubricating agent
in pharmaceutical preparation. It is
mainly used as a drug delivery vehicle.
lubricating gels are also used as a
resistance of gamma radiation.
It is harmless to skin, delicate tissues
and mucous membranes.

26. Other uses
Cosmetic and styling tools:
Hair gel to control hair, make hair
shiny or even to flatten hair.
Body gel to make skin smooth,
shiny and soft.
Silicone gel used to fill breast
implants and to cover scars on the
body or face.