Ointments and Solutions (Week 3)

What are ointments primarily used for?

Ointments are greasy, semi-solid preparations intended for external use.

What are the two main types of ointments?

Medicated and non-medicated ointments.

What is a medicated ointment?

An ointment that contains active ingredients to relieve skin conditions such as infections, inflammation, or itching.

What is a non-medicated ointment?

An ointment that acts as a protectant forming a barrier against irritants or as a lubricant that hydrates and reduces friction.

List the advantages of ointments.

Easy application and retention, lubrication and emollient properties, prolonged drug action, and hydrophobic nature for mucosal use.

LAPH — lubricating and emollient properties (L), A : easy Application and Retention, P: Prolonged Drug Action, H: Hydrophobic nature for mucosal use (prevents itself from being washed away)

What is a disadvantage of ointments?

They can be greasy and difficult to remove, stain clothing, are not suitable for exudating sites, and can have drug release limitations.

What is an oleaginous base in ointments?

A base primarily composed of oils and fats that provide moisture and lubricating properties to the skin. They form barriers to help retain heat, keep moisture and aid in absorption of products spread on the skin before using the ointment.

What does an emulsion base do?

An emulsion base allows for a mix of oil and water to form an emulsion, improving drug release potential in the person’s skin and enhancing spreadability for topical application.

Why are preservatives needed in ointments?

To prevent microbial contamination, extend shelf life, and maintain product safety.

When are preservatives particularly necessary?

When there is water content, multi-dose containers, or high risk of microbial contamination during use.

What are the differences between ointments and creams in a pharmacy setting? (acronyms)

All Ointments Will Stop All Cutaneous Damage

• appearance

• occlusiveness

• water content

• skin penetration

• application suitability

• cosmetic application

• drug release potential

What type of solutions are pharmaceutical solutions?

Homogenous, one-phase systems consisting of 2 or more components like a solute, solvent and emulsifying agent that are uniform throughout.

What are some advantages of pharmaceutical solutions?

Easier to swallow, faster onset of action, taste masking, consistent drug distribution/action , and less irritation to the gastric mucosa.
Acronym: FASTER

• F: Faster Onset of Action

• A: Consistent Drug Action (Prolonged Drug Action due to consistent and regular usage)

• S: easier Swallowing

• T: Taste-masking

• ER: Eased Gastric IrRitation

What are some disadvantages of solutions?

Bulky, shorter shelf life, risk of microbial growth, variable dosage accuracy, and unpleasant taste

(BLAST)

• B — BULKY

• L — shorter shelf LIFE

• A — varying dosage ACCURACY (amount that is applied or used is patient-dependent) → can be too much or too little based on preference.

• S — Microbial Susceptibility (Risk of microbial growth)

• T — unpleasant TASTE (still difficult to mask)

Name the types of solution forms.

Elixirs, eye drops, ear drops, nose drops, syrups, lotions, and IV/IM injections.

What are the components to consider adding into solutions?

Solvents and solubility considerations, formulation additives (buffers/preservatives/coloring/flavoring/sweetening agents

What are the different types of solvents used in pharmaceutical solutions?

Potable water, purified water, and water for injections.

What is the advantage of using purified water in solutions?

It has low toxicity, is compatible with bodily fluids/physiological processes (no adverse reactions), and can dissolve a wide range of materials.

Why is solubility an important consideration in drug formulation?

It affects the drug's bioavailability, therapeutic efficacy and onset of action of the drug in the cream/ointment/solution.

What is an example of using complexation in improving aqueous solubility?

Using cyclodextrin to combine poorly soluble drugs with a soluble material to enhance dissolution rates. The outer layer is able to pass through the cell membrane to enter in cell membranes or specific parts of the body or bloodstream, and dissolve to be absorbed to exert its effect on the body.

When should non-aqueous solutions be used?

When complete solution of ingredients cannot be ensured at storage temperatures or when there is instability in aqueous systems.

What is depot therapy? Explain the process of how depot therapy works briefly/

A method using non-aqueous solutions to allow for slow drug release into surrounding tissue. This occurs when the drug enters the body via the bloodstream, and hides in the muscle tissue within the water-in-oil emulsion to accumulate into a hidden drug entity/reservoir to be released slowly to exert its effect slowly over a longer period of time.

What does 'fixed oils' refer to in drug formulations?

Oils of vegetable origin, such as almond or arachis oil.

What are some drawbacks of using water as a solvent?

It lacks selectivity and can absorb impurities and contaminants that are also dissolvable in water as a solvent.

How can one improve aqueous solubility?

Using co-solvency, pH control, and solubilization.

What are some key considerations when selecting alternative solvents?

Toxicity, irritant potential, sensitizing potential (how easily it causes allergic reactions in people) stability, cost, and compatibility with other excipients.

What are other ways to improve aqueous solubility?

• reducing particle size → increase surface area

• complexation → hide the drug within a soluble solvent/solute to enter the body to exert its effect slowly

• chemical structure modification of the drug → modify it to be less polar to be able to cross the cell membrane with ease.

What are the alternative solvents that we can use other than the three different types of water?

• alcohol (ethanol etc.. present in low concentrations in IV and salicylic acid

• polyhydric alcohols (PEG400 topical, Digoxin which is propylene glycerol mix with glycerol/water solvent to dissolve it or for phenobarbital injections [PB]

what is considered high risk of microbial contamination while using creams/ointments/solutions?

• e.g. repeated application with multi-dose containers and drug to treat broken or infected skin injuries

what are the different factors that we use to compare different ointments bases that we use in ointments/solutions/creams?

• Clever Whales Always Wash Greasy Oil During Underwater-trips

• C: Composition

• W: Water content

• A: Application Suitability

• W: Washability

• G: Greasy — is it greasy?

• O: Occlusiveness

• D: Drug Release Potential

• Example Usage.

What are the different types of bases that we can create or use for creating emulsions/ointments/creams?

Worms Eat Old Apples

• W: Water-soluble

• E: Emulsion-based

• O: Oleaginous-based

• A: Absorption-based

what does oleaginous mean — and what does it do on the skin when applied?

oleaginous → greasy and thick substances that protects the skin barrier by creating an oily barrier on the skin surface

when applied → helps to trap and retain heat → helps with absorption of the drug and other products that is trapped underneath the formed barrier → prevents evaporation of water from aqueous environment of the skin to provide soothing and cooling effect.

What are the disadvantages of using ointments to treat skin conditions etc..?

• greasy and thick in appearance

• easily stains clothing etc.. (bleaching by benzoyl peroxide)

• cannot be used/ineffective when used on exudating sites

• drug release limitations for ointments that have water-soluble drugs that might not be able to absorb well due to the reduced/inability to partition from the ointment into the skin’s aqueous environment due to its hydrophobic nature.

what are the different categories that ointments/creams/oils can be placed under?

• medicated and non-medicated

what does it mean for ointments to be medicated or non-medicated?

• medicated → contains an active ingredient that helps to soothe and treat chronic skin conditions like infections, inflammation and irritation

• non-medicated → does not contain active ingredients and with the main purpose of soothing skin conditions by acting as protectants to form barriers to protect, hydrate, moisturize and lubricate the skin surface to reduce friction