Semisolids

Question 1

Ointments

Answer 1

• Semisolid preparations intended for external application to the skin or mucous membranes
• Medicated or non-medicated
• Used for physical effects - protectants, emollients, lubricants

Question 2

Ointment Bases (4)

Answer 2

1. Oleaginous (hydrocarbons)
2. Absorption bases
3. Water removable bases
4. Water soluble bases

More hydrophilic as you go down

Question 3

Oleaginous Bases

Answer 3

-Emollient effect on skin (occlusive)
-Reside on skin for prolonged periods
-Difficult to wash off
-Small amounts of water and aqueous preparations can be incorporated with difficulty
-Solids can be incorporated with levigation
EX: Petrolatum, White Petrolatum, Yellow & White Ointment

Question 4

Absorption Bases

Answer 4

-Those that permit the incorporation of aqueous solutions resulting in W/O emulsions
-W/O Emulsions permit additional quantities of aqueous solutions
-Not as occlusive as oleaginous bases, semi-occlusive, not easily removed with water
EX: Hydrophilic Petrolatum, Lanolin

Question 5

Water Removable Bases

Answer 5

-O/W Emulsions resemble creams
-Easily washed from skin
-Able to be diluted with water or aqueous solutions
-Can absorb serous discharge
EX: Hydrophilic ointment

Question 6

Water Soluble Bases

Answer 6

-No oleaginous components
-Completed water-washable (greaseless)
-Does not incorporate water or aqueous solutions well (softens)
-Cetyl or steryl alcohol is added to increase firmness
-Mostly used for incorporation of solids
EX: Polyethylene Glycol Ointment

Question 7

Selection of Appropriate Bases Considerations (7)

Answer 7

1. Desired release rate
2. Topical or percutaneous absorption
3. Degree of occlusion of moisture from the skin
4. Stability of drug in base
5. Effect, if any, of drug on consistency of base
6. Water washability
7. Surface to be applied (dry/scaly v.s. weeping skin)

Question 8

Preparations of Ointments (2)

Answer 8

1. Fusion

2. Incorporation

Question 9

Fusion

Answer 9

• All or some of the components of an ointment are combined by melting together and cooled with constant stirring until congealed
• Highest MP substances are melted first then others follow in order based on MP
• Non-melting components are added during constant stirring in the cooling stages

Question 10

Incorporation

Answer 10

• Components are mixed until uniform
• Can use a mortar and pestle or an ointment slab and spatula

Solids

• Use geometric dilution to combine base and fine powders (mixed in mortar/pestle) together uniformly
• Use levigation to mix solid material in a vehicle in which it is insoluble (like glycerin or mineral oil) to make a smooth dispersion

Liquids

• Need to consider base capacity to absorb liquid
• May use small amount of hydrophilic base (incorporated with liquid) to add to hydrophobic base
• Small amounts of alcohol solutions can also be added to oil bases

Question 11

Compendial Requirements (5)

Answer 11

1. Microbial content
2. Minimal Fill
3. Packaging
4. Storage
5. Labeling

Question 12

Microbial Content

Answer 12

• Not sterile (unless ophthalmic), but has requirements
• Preservatives (Sorbic acid, phenols, Methyl or Propylparaben are examples)
• Preparations with water tend to have a larger chance of harboring growth
• Certain preparations are checked for specific agents

Question 13

Dermatologicals + Microbial Content

Answer 13

Checked for P. Aerginosa and S. Aureus

Question 14

Rectal/Urethral/Vaginal + Microbial Content

Answer 14

Checked for yeast and mold

Question 15

Minimal Fill

Answer 15

Used to determine net weight and volume of contents of filled containers to ensure labeled amounts.

Question 16

Packaging

Answer 16

• Packaged in well-closed, large mouth jars or metal/plastic tubes to protect against contamination
• Store light sensitive products in opaque or light resistant containers

Question 17

Storage

Answer 17

Cool place to protect against heat which can cause separation.

Question 18

Labeling

Answer 18

Normal labeling requirements plus USP directions that labeling for some ointments include the base used (water soluble or insoluble).

Question 19

Creams

Answer 19

• Semisolid preparations with 1+ medicinal agents dissolved or dispersed in W/O or O/W emulsion
• Vanishing creams - larger amount of water that dissolve after application and leaves behind a thin residue of oleaginous base
• Primarily used topically, but also vaginally and rectally
• Many patients and physicians prefer creams due to their spreadability and ease of removal

Question 20

Gels

Answer 20

• Semisolid system consisting of dispersions of small or large molecules in an aqueous, liquid behicle made jellylike by a gelling agent
• Gelling agents - synthetic macromolecules, cellulose derivatives, natural gums
• Can have varying viscosities, thicken upon standing (thixotrope), must shake before use to allow pouring

Question 21

Single Phase Gels

Answer 21

Macromolecules are uniformly distributed throughout liquid with no boundaries

Question 22

Two Phase Gels

Answer 22

Floccules of small, distinct particles. AKA - Magma

Question 23

Paste

Answer 23

• High proportion of solid materials (25%)
• Stiffer than ointments
• Prepared similarly to ointments but levigation agent is part of base
• Remain in place after application and can absorb serous secretions
• Not suited for hairy body parts (difficult to remove)

Question 24

Plasters

Answer 24

• Solid or semisolid masses spread on some sort of backing
• Also have an adhesive and are applied to skin for prolonged contact
• Different sizes to conform to site being covered
• Used today in pain relief “patches” (EX: Tiger Balm)

Question 25

Glycerogelatins

Answer 25

- Plastic masses containing 15% gelatin, 40% glycerin, 35% water, and 10% medicinal agent - Applied to skin for long term effect - Following application, glycerogelatin hardens and is covered with bandage & allowed to stay in place

Question 26

Liquid Bandage

Answer 26

- Topical skin treatment which creates polymer layer on skin and protects the wound from dirt and germs - Also keeps moisture in - Similar to glycerogelatins but use water and oil-based polymers

Question 27

Semisolid Application Sites (6)

Answer 27

1. Topical 2. Transdermal 3. Ophthalmic 4. Rectal 5. Vaginal 6. Nasal

Question 28

Topical Application

Answer 28

Designed to deliver drug into the skin with the skin as the target organ.

Question 29

Transdermal Application

Answer 29

Designed to deliver drug through the skin to general circulation with the skin not being the target organ.

Question 30

Semisolid Use of Dermatological Preparations

Answer 30

- Topical treatment of skin diseases - Penetration depends on physicochemical properties of active ingredient, characteristics of vehicle, and the condition of the skin - Therapeutically effective drug concentrations are NOT known; treatment should be based on qualitative measures which can vary between products and patients

Question 31

Ophthalmic Preparations

Answer 31

- Topical treatment of conditions and diseases of the eye - Application of drug to eye or conjuctiva affects the surface of eye and underlying tissues - Major role of entry is diffusion through cornea - Conjunctiva and sclera are alternate routes - Lipophilic drugs penetrate easier - Limited drug penetration due to lack of residence time, decreased surface area, and the eye's natural resistance to penetration - Ophthalmic ointments can mitigate the decreased residence time

Question 32

Ophthalmic Base Properties (4)

Answer 32

1. Non-irritating 2. Must permit diffusion of medicine in secretions that bathe the eye 3. Should have softening point that is near body temperature to comfort patient and allow for drug release 4. Drugs are added as solution or micronized particles

Question 33

Ophthalmic Preparation Tests (2)

Answer 33

1. Sterility Tests | 2. Metal Particle Tests

Question 34

Sterility Tests

Answer 34

- Normalizing sterilizing procedures may not be appropriate for ophthalmic - Strict methods for aseptic processing are employed including each component and the active ingredient being sterilized before creating the product and adding preservatives

Question 35

Metal Particle Tests

Answer 35

- Melted ointment is physically examined under microscope for metal particles - Passing requires there to be <50 metal particles per 50 um or larger from 10 product tubes - Can have no more than 8 metal particles in each tube

Question 36

Nasal Preparations

Answer 36

- Topical treatment of nasal mucosa - Nasal surface coated with mucous layer that contains lysosomes, glycoproteins, and immunoglobulins that act as defenses to protect the lungs - Move by cilliary action and can cause the sneeze reflex - Drugs are primarily used for local affects like decongestants - Can also use systemically since they have access to a rich blood supply

Question 37

Rectal Preparations

Answer 37

-Topical application to perianal area and insertion into rectal canal -Healthy skin is a barrier to drug penetration and infections -Drugs may be systemically absorbed but systemic affect is limited by drug insolubility -Treats local conditions like inflammation or pain form hemorrhoids EX: Astringents, protectants, lubricants, local anesthetics, and anti-inflammatories

Question 38

Perianal Area

Answer 38

Skin that is immediately surrounding anus, has mucous linings.

Question 39

Vaginal Preparations Uses (4)

Answer 39

1. Vulvovaginal infections - clotrimazole, micronazole, clindamycin, nystatin, sulfonamides 2. Vaginitis - anti-inflammatories 3. Endometrial Atrophy - locally with dienestrol and progesterone 4. Contraception - spermicidal agents