Questions and Answers
Define semisolids.
A system that is not pourable and does not flow under low shear stress at room temperature.
List 5 semisolid dosage forms.
- Ointments 2) Creams 3) Gels 4) Pastes 5) Collodions
Define ointment.
Semisolid preparations incorporated into a hydrocarbon base intended for external application, usually containing less than 20% water and greater than 50% hydrocarbon.
Define creams.
Signup and view all the answers
Define gels.
Signup and view all the answers
Define paste.
Signup and view all the answers
Define collodions.
Signup and view all the answers
What are the indications of an emollient?
Signup and view all the answers
What are the indications of a protective semisolid?
Signup and view all the answers
What are the indications of an occlusive semisolid?
Signup and view all the answers
What are the indications of a humectant?
Signup and view all the answers
What are the indications of medicated semisolids?
Signup and view all the answers
Give an example of a local and a systemic effect medicated semisolids might be used for.
Signup and view all the answers
What are the desirable properties of a semisolid base?
Signup and view all the answers
What are the four general classes of ointment bases?
Signup and view all the answers
Hydrocarbon bases will not absorb water.
Signup and view all the answers
What indications are hydrocarbon bases good for?
Signup and view all the answers
What is one disadvantage of hydrocarbon bases?
Signup and view all the answers
What are three advantages of hydrocarbon bases?
Signup and view all the answers
Hydrocarbon bases are soluble in water.
Signup and view all the answers
How would you remove a hydrocarbon base?
Signup and view all the answers
What are the two classes of absorption bases?
Signup and view all the answers
Describe anhydrous absorption bases.
Signup and view all the answers
Describe water in oil emulsion absorption bases.
Signup and view all the answers
Anhydrous bases cannot absorb water.
Signup and view all the answers
What indications are anhydrous bases appropriate for?
Signup and view all the answers
What problem do the emulsifying agents in anhydrous bases cause?
Signup and view all the answers
Anhydrous bases are insoluble in water.
Signup and view all the answers
Anhydrous bases can be washed off with water.
Signup and view all the answers
What is the difference between anhydrous and W/O bases?
Signup and view all the answers
Absorption bases have better occlusive properties than hydrocarbon bases.
Signup and view all the answers
How can absorption bases be used with hydrocarbon bases?
Signup and view all the answers
O/W bases can absorb water.
Signup and view all the answers
What are two disadvantages of O/W bases?
Signup and view all the answers
What is one advantage of O/W bases?
Signup and view all the answers
O/W bases may have _____________, ______________ or _________________ problems.
Signup and view all the answers
O/W bases are soluble in water.
Signup and view all the answers
O/W bases are water-washable.
Signup and view all the answers
O/W bases can absorb some _________ or _________.
Signup and view all the answers
O/W bases will allow the ____________________________________.
Signup and view all the answers
Water soluble bases can absorb water.
Signup and view all the answers
What properties do water soluble bases not possess?
Signup and view all the answers
What is one advantage of water soluble bases?
Signup and view all the answers
Water soluble bases may have _______________, ___________________ or _______________ problems.
Signup and view all the answers
What is one disadvantage of water soluble bases?
Signup and view all the answers
Water soluble bases are water washable.
Signup and view all the answers
The term cream used to be used for ______________, but is now used for __________________ or __________________ or __________________.
Signup and view all the answers
What are four things to consider when choosing a base?
Signup and view all the answers
What are the two ways to compound semisolid dosage forms and which is the most common?
Signup and view all the answers
Define levigation.
Signup and view all the answers
When would you not use levigation?
Signup and view all the answers
Define levigating agents.
Signup and view all the answers
What are four examples of the most common levigating agents?
Signup and view all the answers
What types of bases are propylene glycol, PEG 400 and glycerin used as levigating agents in?
Signup and view all the answers
What types of bases is mineral oil used as a levigating agent in?
Signup and view all the answers
What are three examples of the less common levigating agents?
Signup and view all the answers
What is the general rule for choosing a levigating agent?
Signup and view all the answers
What levigating agent would you choose for an oily base?
Signup and view all the answers
What levigating agent would you choose for a water removable base?
Signup and view all the answers
What are the determining factors for the amount of levigating agent you should use?
Signup and view all the answers
What is the general rule for the amount of levigating agent you should use?
Signup and view all the answers
What do you do with crystalline agents that are difficult or impossible to levigate?
Signup and view all the answers
What are the two categories of solvents?
Signup and view all the answers
What types of liquids are hydrocarbon bases able to absorb?
Signup and view all the answers
What types of liquids are anhydrous absorption bases able to absorb?
Signup and view all the answers
What types of liquids are W/O emulsion bases able to absorb?
Signup and view all the answers
What types of liquids are water removable bases able to absorb?
Signup and view all the answers
What types of liquids are water soluble bases able to absorb?
Signup and view all the answers
What are four things you could do if the solution is not absorbed into the base?
Signup and view all the answers
How could you add aqueous liquids to hydrophobic bases?
Signup and view all the answers
What is pulverization by intervention used for?
Signup and view all the answers
What is the process of pulverization by intervention?
Signup and view all the answers
How do you make ointments that do not mix well by incorporation?
Signup and view all the answers
Explain the fusion method.
Signup and view all the answers
What are the characteristics of pastes?
Signup and view all the answers
Semisolids are required to be sterile.
Signup and view all the answers
How do you minimize microbial content in semisolids?
Signup and view all the answers
Study Notes
Semisolids Overview
- Semisolids are non-pourable, retaining shape without flowing when subjected to low shear stress at room temperature.
Semisolid Dosage Forms
- Common forms include ointments, creams, gels, pastes, and collodions.
Ointments
- Comprised of less than 20% water and more than 50% hydrocarbons.
- Designed for external applications in a hydrocarbon base.
Creams
- Formulated to have a relatively fluid consistency as either water-in-oil (W/O) or oil-in-water (O/W) emulsions.
- Contain more than 20% water and less than 50% hydrocarbons, utilizing waxes or polyols.
Gels
- Comprise suspensions of small inorganic or large organic molecules interspersed with liquid.
Pastes
- Contain a high proportion (20-50%) of solid particles evenly dispersed within a fatty vehicle.
Collodions
- Thick solutions made from pyroxyline dissolved in a mixture of alcohol and ether.
Indications for Semisolids
- Emollients: Soften skin and soothe irritation.
- Protective semisolids: Shield injured skin from harmful stimuli.
- Occlusive semisolid: Retain moisture by forming hydrophobic barriers.
- Humectants: Hydroscopically retain water.
- Medicated semisolids: Serve as vehicles for local or systemic drug delivery.
Types of Ointment Bases
- Four general classes: hydrocarbon, absorption, water-removable, and water-soluble bases.
Hydrocarbon Bases
- Do not absorb water, beneficial for their emollient, occlusive, and protective properties.
- Disadvantages include leaving an oily residue.
- Examples include mineral oil, which can be removed with warm water and soap.
Absorption Bases
- Classified into anhydrous and water-in-oil emulsions.
- Anhydrous bases have the highest water absorption capacity and may cause irritation or stickiness.
Water-in-Oil (W/O) Emulsion Bases
- Contain water and have limited additional water absorption capacity.
Oil-in-Water (O/W) Bases
- Can absorb some water and alcohol; less emollient and can dry out.
- Non-greasy construction is an advantage.
Water-Soluble Bases
- Absorb limited amounts of water and alcohol; do not leave an oily residue but may be irritating.
Choosing Ointment Bases
- Consider desired action, systemic versus local effects, properties of the base, and physico-chemical properties like solubility and compatibility.
Compounding Methods
- Two primary methods: incorporation (most common) and fusion.
- Levigation involves reducing particle size using a viscous liquid where solids are insoluble.
Levigating Agents
- Agents such as glycerin, propylene glycol, mineral oil, and PEG 400 are used based on compatibility with the base.
- Choose similar chemical agents for effective results.
Handling of Solutions
- If a solution does not absorb into the base, options include changing the base, adding emulsifiers, or incorporating solvents.
Microbial Control in Semisolids
- Minimize microbial content through environmental control, preservatives, and good manufacturing practices.
- Sterility is not typically required unless for ophthalmic uses.
Fusion Method
- Involves melting chemicals together, cooling, and adding heat-sensitive ingredients at the proper temperature.
Characteristics of Pastes
- Pastes are less greasy, stiffer, and designed to remain in place while absorbing secretions.
Understanding Semisolid Properties
- Key desirable properties include stability, non-reactivity, and aesthetic appeal, ensuring product effectiveness and safety.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the essential aspects of semisolids, including definitions, common dosage forms, and specific examples like ointments, creams, gels, and pastes. Learn about their compositions, uses, and therapeutic indications in pharmaceutical applications.