compounding 2

Gels

Semisolid systems with suspensions composed of small inorganic particles or large organix molecules interpenetrated by a liquid 

What are gels considered

Collodial dispersions

What bonds make gels viscous

Hydrogen bonds

What is a 2 phase system gel

If a gel contains small discrete particles

What is a one phase system 

When gel doesn’t have discreet particles

What are 2 phase systems known as

thixotropic so they are semisolid on standing but liquefy when shaken

If the particle size of the 2 phase system is large what is it known as

Magma

Examples of 2 phase gels

Aluminum hydroxide 

Bentoinite Magma 

What do single phase systems contain

Linear or Branched polymer macromolecules with the dispensing medium which are natural polymers, semisynthetic cellulose derivatives, synthetic polymers

What are common gelling agents

Carboxhol 971

Acrylic Acid Polymers

Why do we avoid natural polymers

Can be contaminated

What are some problems when making gels

If gelling agent added to quick it can clump

How to avoid clumping

Seive

Rate of addition of gelling agent

Stirring

Which gelling agents are soluble in cold water

Hydroxypropylmethyl cellulose 

Poloxamers

Which gelling agents disolve in hot water

Carbomers

Tragacanth

Algninc acid gels

What does viscosity depend on

Temp

Ions

pH

Concentration of Polymer

What is Carbocol

Gelling agent that is acrylic acid polymide with low PH 

What happens to the solution when carbomer is added

Leads to a low pH

How to increase pH of gel solutions and thicken

Add a neutralizer

Examples of neutralizers

Sodium Hydroxide

Potassium hydroxide 

triethanolamine

What is the range of viscosity of gel solutions

o-80000 cps

What is the effect of Methylcellulose on gels

Make them thinner and is added for gels with high tolerance of added drugs and salts.

Swells in Hot water

What is the effect on gels when Hydroxypropylmethylcellulose is added

Makes thicker gels but low tolerance for positive charged ions

Which gelling agent good for timed release

Hydroxypropylmethylcellulose

What is the effect of Carboxymethylcellulose on gels

Generally used as the sodium salt and makes thicker gels

What do Poloxamers form 

Thermoreversible fels which are cool in the fidge and then gels at room temperature

Are organic solvents used for Poloxamers

No because it itself is a surfectant

What is Pluronic combined with

Lecithin and Isoproyl pamitate to make PLO gel leading to 2 seperate phases

When compounding water soluble drugs what is it dissolved in in regards to PLO

PLO gel

When compounding oil soluble drugs what is it dissolved in in regards to PLo

Lecithecin syrup

What is a Olegineous Base

Insoluble in water and doesnt absorb water

Greasy

Examples of Oligeneous Bases 

Vaseline

What is an absorption base

Can absorb water

Anhydrous

W/O base

Examples of Absorption base

Aquaphor

Lanolin

Cold Cream

What is a Water Miscible base

o/w emulsion

nsoluble in water 

Water washable

Contain and absorb water

Ex of Water Miscible base

Hydrophillic ointment

Vanishing cream

What is a water soluble base

Water soluble

Washable

Example of Water Soluble Base

PEG ointment

What type of base for dry skin

Occlusive 

What type of base for wet skin

Water removable

What is used for small scale particle size reduction

Levigation

What is used for large scale size reduction

Ointment mill

Examples of levigating agents

Mineral oil

Castor oil

Glycerin

What is levigation

Process of incorporating a solid by triturating it into mortar and using a viscous levigating agent

How does an ointment mill work

Uses high shear force to reduce particle sizes disperse agglomerates and homogenize viscous materials

What is Fusion

Melting together bases over a water bath before incorporating other ingredients. All components are melted together

What are ointment tubes made of

Aluminum or plastic

What are plastic tubes made of 

High or low density polyethylene

Ointments vs creams

Ointments usually 80% olegineous base and are more greasier and creams are 50/50 water

What are creams a better option for

Greasy or oily skin

What are creams

Semisolid dosage forms with one or more drug substances dissolved or dispersed in a suitable base

Which type of cream emulsion is preferred

O/W

What are the types of creams

O/W

W/O

Examples of O/W cream

Foundation

Hand creams

Shaving cream

Vanishing cream

Examples of W/O cream

Cold creams 

Emollient creams 

What is monophasic

One phase

Which solutions are monophasic

Solution

drops

syrups

elixers

What is biphasic

One phase distributed/dispersed into another

Do you add preservatives to Iv preparations

No

What bacteriostatic agent stops microbial growth in IV

benzyl alcohol

What are preservatives used on liquid dosage forms

Methyl baraben

Sodium benzoate

Benzoic acid