Podcast
Questions and Answers
Which of the following options is NOT a characteristic of a suitable levigating agent?
Which of the following options is NOT a characteristic of a suitable levigating agent?
What type of base is mineral oil typically used with?
What type of base is mineral oil typically used with?
When incorporating a solid that is difficult to grind, which method can be utilized effectively?
When incorporating a solid that is difficult to grind, which method can be utilized effectively?
Which levigating agent is NOT suitable for use with a W/O emulsion base?
Which levigating agent is NOT suitable for use with a W/O emulsion base?
Signup and view all the answers
Which of the following solvents can be classified as water-miscible solvents?
Which of the following solvents can be classified as water-miscible solvents?
Signup and view all the answers
Which ingredient could be dissolved for incorporation into an ointment base when dealing with difficult solids?
Which ingredient could be dissolved for incorporation into an ointment base when dealing with difficult solids?
Signup and view all the answers
What is a critical step when selecting a solvent for a formulation?
What is a critical step when selecting a solvent for a formulation?
Signup and view all the answers
Which emulsion type allows for the incorporation of limited amounts of oil?
Which emulsion type allows for the incorporation of limited amounts of oil?
Signup and view all the answers
Which statement about hydrocarbon bases is true?
Which statement about hydrocarbon bases is true?
Signup and view all the answers
How should the amount of solvent be managed in a formulation?
How should the amount of solvent be managed in a formulation?
Signup and view all the answers
Which of the following is an example of a lipophilic solvent?
Which of the following is an example of a lipophilic solvent?
Signup and view all the answers
What should be checked for solvent compatibility?
What should be checked for solvent compatibility?
Signup and view all the answers
When incorporating an aqueous solution into a hydrophobic base, which type allows for this without significant issues?
When incorporating an aqueous solution into a hydrophobic base, which type allows for this without significant issues?
Signup and view all the answers
Which base type is known to penetrate the skin the least?
Which base type is known to penetrate the skin the least?
Signup and view all the answers
Which solvent is most compatible for improving drug solubility in the stratum corneum?
Which solvent is most compatible for improving drug solubility in the stratum corneum?
Signup and view all the answers
What method is commonly used to dissolve active ingredients in topical formulations?
What method is commonly used to dissolve active ingredients in topical formulations?
Signup and view all the answers
Which type of emulsion would likely provide a lightweight consistency for topical application?
Which type of emulsion would likely provide a lightweight consistency for topical application?
Signup and view all the answers
Which penetration enhancer is characterized as an anionic surfactant?
Which penetration enhancer is characterized as an anionic surfactant?
Signup and view all the answers
Which class of bases provides a significant emollient and occlusive effect?
Which class of bases provides a significant emollient and occlusive effect?
Signup and view all the answers
What type of base allows for easy removal with water?
What type of base allows for easy removal with water?
Signup and view all the answers
Which fatty acid is primarily used as a penetration enhancer in topical formulations?
Which fatty acid is primarily used as a penetration enhancer in topical formulations?
Signup and view all the answers
Which category of surfactants contains no charge and is typically used in emulsions?
Which category of surfactants contains no charge and is typically used in emulsions?
Signup and view all the answers
What is the primary characteristic of endodermic bases?
What is the primary characteristic of endodermic bases?
Signup and view all the answers
Which of the following is a characteristic of water-removable bases?
Which of the following is a characteristic of water-removable bases?
Signup and view all the answers
What is true regarding the emollient properties of water-soluble bases?
What is true regarding the emollient properties of water-soluble bases?
Signup and view all the answers
Which statement correctly describes the formulation of water-removable bases?
Which statement correctly describes the formulation of water-removable bases?
Signup and view all the answers
Which of the following factors influences the selection of an appropriate ointment base?
Which of the following factors influences the selection of an appropriate ointment base?
Signup and view all the answers
What is a common characteristic of both water-soluble and water-removable bases?
What is a common characteristic of both water-soluble and water-removable bases?
Signup and view all the answers
Which type of emulsion is classified as water-removable?
Which type of emulsion is classified as water-removable?
Signup and view all the answers
What happens to water-removable bases upon application?
What happens to water-removable bases upon application?
Signup and view all the answers
Which of the following bases can consistently incorporate solid active ingredients effectively?
Which of the following bases can consistently incorporate solid active ingredients effectively?
Signup and view all the answers
Which of the following is a common type of water-removable base?
Which of the following is a common type of water-removable base?
Signup and view all the answers
What is the effect of adding water to a water-soluble base?
What is the effect of adding water to a water-soluble base?
Signup and view all the answers
What is a characteristic of hydrocarbon (oleaginous) bases?
What is a characteristic of hydrocarbon (oleaginous) bases?
Signup and view all the answers
Which of the following is a reason for selecting a proper ointment base?
Which of the following is a reason for selecting a proper ointment base?
Signup and view all the answers
What is a common property of water-soluble bases in ointment formulations?
What is a common property of water-soluble bases in ointment formulations?
Signup and view all the answers
Which of the following describes the incorporation process in ointment preparation?
Which of the following describes the incorporation process in ointment preparation?
Signup and view all the answers
Which of the following is not an ideal characteristic of an ointment base?
Which of the following is not an ideal characteristic of an ointment base?
Signup and view all the answers
What type of emulsion bases does NOT include water-in-oil (W/O) emulsions?
What type of emulsion bases does NOT include water-in-oil (W/O) emulsions?
Signup and view all the answers
Which of the following ointment bases is characterized as an effective occlusive dressing?
Which of the following ointment bases is characterized as an effective occlusive dressing?
Signup and view all the answers
What is a disadvantage of using hydrocarbon bases in ointment formulations?
What is a disadvantage of using hydrocarbon bases in ointment formulations?
Signup and view all the answers
Which of the following statements is true regarding absorption bases?
Which of the following statements is true regarding absorption bases?
Signup and view all the answers
Which ointment base is classified as an oleaginous base and is known for being non-staining?
Which ointment base is classified as an oleaginous base and is known for being non-staining?
Signup and view all the answers
What distinguishes a pseudoplastic fluid from a Newtonian fluid?
What distinguishes a pseudoplastic fluid from a Newtonian fluid?
Signup and view all the answers
In which scenario is thixotropy particularly beneficial for pharmaceutical formulations?
In which scenario is thixotropy particularly beneficial for pharmaceutical formulations?
Signup and view all the answers
What is the primary concern regarding Pseudomonas aeruginosa in topical preparations?
What is the primary concern regarding Pseudomonas aeruginosa in topical preparations?
Signup and view all the answers
Which type of ointment base is known for containing oleaginous components?
Which type of ointment base is known for containing oleaginous components?
Signup and view all the answers
What is a characteristic function of humectants in dermatological products?
What is a characteristic function of humectants in dermatological products?
Signup and view all the answers
Which characteristic differentiates hydrogels from organogels?
Which characteristic differentiates hydrogels from organogels?
Signup and view all the answers
Why are composition specifics of ointment bases important when incorporating aqueous materials?
Why are composition specifics of ointment bases important when incorporating aqueous materials?
Signup and view all the answers
What defines plastic flow in concentrated suspensions with flocculated particles?
What defines plastic flow in concentrated suspensions with flocculated particles?
Signup and view all the answers
Which type of semisolid formulation is ideal for applying to moist, weeping lesions?
Which type of semisolid formulation is ideal for applying to moist, weeping lesions?
Signup and view all the answers
What is a significant effect of dilatant materials during processing?
What is a significant effect of dilatant materials during processing?
Signup and view all the answers
Study Notes
Ointment Bases
- Hydrocarbon Bases are insoluble in water, anhydrous, and non-absorbing.
- Absorption Bases can absorb water and are categorized as anhydrous or water-in-oil (W/O) emulsions.
- Water-Removable Bases evaporate water leaving a thin film.
- Water-Soluble Bases are anhydrous and do not contain oily compounds.
Classification of Ointment Bases
- Hydrocarbon Bases are anhydrous, insoluble in water, and effective occlusive dressings.
- Absorption Bases can be anhydrous or W/O emulsions; anhydrous bases can absorb large amounts of water and W/O emulsions can absorb smaller amounts.
- Water-Removable Bases are easily washable, non-greasy, and generally more preferable to patients.
- Water-Soluble Bases are completely water-washable, non-occlusive and less emollient.
Ointment Base Characteristics
- Hydrocarbon Bases are greasy, emollient, difficult to wash, and not water-absorbing.
- Absorption Bases have a moderate greasy feel, are emollient, difficult to wash, and absorb water.
- W/O Emulsion Bases are less greasy than hydrocarbon bases, have moderate emollient properties, are slightly difficult to wash, and absorb a small amount of water.
- O/W Emulsion Bases have a creamy appearance, are non-greasy, non-occlusive, and absorb a small amount of water.
- Water-Soluble Bases have no greasy feeling, are not emollient, are easily washed, and absorb water.
Levigation
- Levigating agents should be non-sensitizing, non-allergenic, non-volatile, and should be compatible with the ointment base.
- The right levigating agent should be chosen to avoid incompatibility with the base and the solid being incorporated.
- Levigating agents should be chemically similar to the ointment base, such as mineral oil for petrolatum.
Dissolution
- Solvents are used to dissolve soluble solids prior to adding them to the ointment base.
- Solvents should be considered if the solid is difficult to grind or if the solid is incompatible with the ointment base.
- Solvents should be compatible with the ointment base and other ingredients in the formula.
Penetrant Enhancers
- Penetrant enhancers improve drug solubility in the stratum corneum to increase drug diffusion through the skin.
Criteria for Selecting an Ointment Base
- Key considerations include the desired drug release rate, the site of drug action, and the desired level of skin penetration.
Topical Dosage Forms
- Ointments are semi-solid preparations intended for external application to the skin.
- Ointments are typically classified according to their interaction with water and their physical properties.
Rheology, Viscosity & Fluidity
- Rheology: The study of the flow of matter, especially under stress.
- Viscosity: A measure of a fluid's resistance to flow. Higher viscosity means more resistance.
- Fluidity: The opposite of viscosity; a measure of how easily a fluid flows.
- Shear rate: The rate of change of velocity across a fluid. Higher shear rate means the fluid is moving faster.
- Shear stress: The force per unit area required to deform a fluid. Higher shear stress means the fluid is being pushed harder.
Newtonian & Non-Newtonian Fluids
- Newtonian: Fluids with a constant viscosity, regardless of shear rate. Examples include water, honey, and oil.
-
Non-Newtonian: Fluids with viscosity that changes with shear rate.
- Pseudoplastic: Viscosity decreases with increasing shear. Examples include polymers in solution like shampoo, hair gel, and some paints.
- Dilatant: Viscosity increases with increasing shear. Examples include suspensions with high solid content like cornstarch in water.
- Plastic: Requires a minimum shear stress (yield value) before flow begins. Examples include flocculated suspensions like toothpaste, creams, and ointments.
Thixotropy
- Thixotropy: A time-dependent property where a fluid's viscosity decreases with longer periods of shear stress. As shear stress is removed, viscosity slowly recovers.
- Pharmacy Applications: Thixotropic materials are useful for products requiring a stable, easy-to-apply consistency, but also a fluidity upon application.
Dermatological Products
- Topical: Applies to the skin's surface.
- Transdermal: Penetrates through the skin to deliver medication.
- Emollients: Soften and smooth skin.
- Humectants: Attract and retain moisture.
- Stiffening Agents: Increase the viscosity or consistency of a formulation.
- Protectants: Form a barrier on the skin to prevent irritation or moisture loss.
- Rubefacients: Produce redness and warmth on the skin.
- Counterirritants: Relieve pain by creating a sensation of irritation.
- Antioxidants: Prevent or inhibit oxidation.
- Penetration Enhancers: Increase the permeability of the skin to allow medication to pass through.
- Ointments: Semisolid preparations for topical application.
- Creams: Semisolid, emulsion-based preparations for topical application.
- Pastes: Thick, stiff semisolid preparations for topical application.
- Plasters: Medications in a solid or semisolid form meant to adhere to the skin.
- Glycerogelatins: Semisolid preparations containing glycerin and gelatin.
- Gels: Semisolid preparations with a jelly-like consistency.
- Lotions: Thin, liquid preparations for topical application.
- Liniments: Liquid preparations for topical application, typically containing oil and alcohol.
- Collodions: Liquid preparations that form a film on the skin upon drying.
- Topical powders: Fine, dry preparations for topical application.
- Sticks: Solid preparations for topical application.
Ointment Bases
- Oleaginous: Oil-based, non-aqueous.
- Absorption: Contain oleaginous components that can absorb water.
- Water-Removable: Can be washed off with water.
- Water-Soluble: Water-based, non-oleaginous.
Topical Formulation Considerations
- Levigating Agents: Used to reduce the particle size of solids in ointments to improve smoothness.
- Pseudomonas aeruginosa & Staphylococcus aureus: These bacteria are of concern because they can cause skin infections and are commonly found in topical preparations.
- Preservatives: Parabens and benzoic acid are common preservatives used to prevent microbial growth.
- Moist, Weeping Lesions: Use a water-removable or water-soluble ointment base; these bases will not further irritate the skin.
- Dry, Scaly Lesions: Use an oleaginous or absorption base; these bases will help to moisturize and soften the skin.
Gels & Liniments
- Hydrogels: Gels containing water as the primary solvent.
- Organogels: Gels containing a non-aqueous solvent like oil or alcohol.
- Thermoreversible Gels: Gels that change their viscosity with temperature. This is helpful as it allows for easier application at room temperature but maintains a firmer consistency when applied to the skin.
- Carbomers: Synthetic polymers that form gels when in contact with water.
- Liniments: Should not be applied to bruised skin because the alcohol content can cause further irritation.
- Collodion: Camphor is used to provide antiseptic properties, and castor oil acts as a film-forming agent to create a protective layer on the skin.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the various types of ointment bases used in pharmaceutical applications. Learn about hydrocarbon bases, absorption bases, water-removable bases, and water-soluble bases, along with their characteristics and classification. Test your knowledge on the properties and uses of these bases in formulation science.
