7 Types of Non-Sterile Compounds

Pharmacy compounding allows for the personalized preparation of medications when commercial products are unavailable, inappropriate, or unsuitable for a patient’s specific needs. This chapter introduces some of the most commonly compounded non-sterile dosage forms encountered in pharmacy practice. For clarity and practical understanding, these dosage forms are grouped into two broad categories: oral and topical preparations. While each formulation type has its unique characteristics, benefits, and limitations, all must meet established compounding standards to ensure safety, efficacy, and quality.

By examining each formulation type—solutions, syrups, suspensions, emulsions, capsules, creams, ointments, gels, lotions, and pastes—this chapter provides pharmacy personnel with foundational knowledge to support safe and effective compounding practices, aligned with NAPRA and provincial standards.

1. Oral Compounds

An oral pharmacy compound is a custom-prepared medication designed for systemic absorption through oral administration. It is formulated by a compounding pharmacist to meet the specific needs of a patient when commercially available medications are unsuitable.

Oral compounds may be required for:

• Dosage adjustments (e.g., pediatric or geriatric patients needing lower strengths)
• Allergen-free formulations (e.g., removing dyes, gluten, lactose, or preservatives)
• Flavor customization (e.g., improving palatability for children or pets)
• Combining multiple medications into a single dose to improve adherence

Common Oral Dosage Forms in Compounding

1. Solutions, Suspensions, Emulsions – Liquid preparations where drugs are either fully dissolved (solutions) or dispersed (suspensions) or 2 phase liquid (emulsion) in a flavored or medicated base.
2. Syrups & Elixirs – Sweetened liquids used to enhance palatability.
3. Capsules – Custom-filled gelatin or vegetarian capsules containing specific drug doses.
4. Troches & Lozenges – Dissolvable solid forms used for buccal or sublingual absorption.

Oral pharmacy compounds are commonly used for hormone replacement therapy (HRT), pain management, pediatric and veterinary medicine, and patients with swallowing difficulties or medication sensitivities.

The most common compounded liquids are solutions, suspensions, emulsions, syrups and capsules.

Solutions:

A solution is a homogenous liquid preparations where the active ingredient (API) is fully dissolved in a solvent. The solvent is usually water, however there are also other solvents that may be used such as glycerin, alcohol or propylene glycol. Solutions are widely used in pharmacy for oral prescriptions, but you will also see them used for topical, ophthalmic, otic, and parenteral drug delivery.

Characteristics of a Well-Formulated Solution:

• Clear and homogeneous – No visible particles or precipitates
• Stable – Chemically and physically stable under recommended storage conditions
• Proper solubility – Active Pharmaceutical Ingredient (API) is fully dissolved in the solvent
• Palatable (for oral solutions) – Sweeteners, flavors, or viscosity enhancers may be added
• Isotonic (for ophthalmic and parenteral solutions) – Ensures compatibility with body fluids

Advantages of Solutions:

• Easy adjustment and customization of dose – Adjusting the volume makes solutions ideal for individualized therapy.
• An option for people who can’t swallow pills – Suitable for children, older adults, or patients with dysphagia.
• The taste can be masked – Flavouring agents can be added to improve palatability, especially for pediatric patients.
• Uniform distribution of the drug, no need for shaking – Since the drug is fully dissolved, each dose contains the same amount of active ingredient.
• Fast onset of action, as the API is already dissolved – The drug doesn’t need to dissolve in the body, leading to quicker absorption and effect.
• Easy to administer – Can be given with a measuring device like an oral syringe or cup, which is convenient and flexible.

Disadvantages include:

• Reduced stability – Solutions are more prone to chemical degradation.
• Shorten beyond use date – Due to limited stability, or water content, compounded solutions often have a short shelf life.
• Storage, transportation issues – May require refrigeration or special containers.
• Taste masking challenges, especially for bitter-tasting drugs – Some drugs are extremely bitter and difficult to mask completely.
• Requires dosing/measurement device – Accurate dosing depends on the proper use of oral syringes or medicine cups, which can be confusing.

Often there are additional ingredients used in oral solutions, such as preservatives, sweeteners, colorants or viscosity enhancing agents. Each time another ingredient is added, you must consider how it will affect the effectiveness and stability of the final product.

Examples of Commonly Compounded Solutions:

• Oral solutions (e.g., Diphenhydramine hydrochloride solution for allergies)
• Topical solutions (e.g., Aluminum acetate solution for skin irritation)
• Ophthalmic solutions (e.g., Artificial tears or antibiotic eye drops)
• Parenteral solutions (e.g., IV dextrose or electrolyte solutions)
• Mouthwashes/gargles (e.g., Chlorhexidine mouth rinse for oral hygiene)

Solubility:

• Ability of a solute to dissolve in a solvent to form a homogenous mixture
• Important to consider to ensure drug stays in solution (storage and dosing)
• Can be affected by temperature – Consider temperature/solubility during preparation versus storage
• Want to dissolve solids in the liquid they are most soluble in
• Solubilities given in standard references like the USP, Martindales, safety data sheets

USP/NF and BP Solubility Criteria:

Enhancing Solubility:

• Smaller particle size, micronization
• Heating
• Dispersing drugs in carriers such as eutectic mixtures (lowers melting point)
• Using co-solvents

Miscibility:

• A term that is used to describe how two liquids can mix together completely to form a single, uniform solution
• Miscible = mixed in any proportion, they will mix
  • water is miscible with alcohol
• Immiscible = substances do not mix
  • oil is immiscible with water

Syrups:

A syrup is a concentrated aqueous solution of sugar or sugar substitutes. It is a homogeneous, viscous, sweetened liquid dosage form with or without an active pharmaceutical ingredient (API), flavoring agents, or preservatives.  Syrups are primarily used for oral administration and are often flavored to enhance palatability, mask unpleasant taste and enhance patient compliance, especially for pediatric and geriatric patients.

The most common type is Simple Syrup USP, which consists of 85% sucrose in purified water and acts as a base for medicated syrups.

Characteristics of a Well-Formulated Syrup:

• Clear and homogeneous – Free from turbidity or precipitation
• Sweet and palatable – Masks the taste of bitter APIs
• Adequate viscosity – Thick enough to coat the throat but easy to pour
• Preservative-stabilized – Prevents microbial growth due to high sugar content
• Non-crystallizing – Avoids sugar crystallization upon storage

Advantages of Syrups:

• Taste Masking- Effective for bitter or unpleasant-tasting drugs.
• Soothing effect- Thick consistency provides a demulcent (soothing) effect, useful for cough syrups.
• Uniform Drug Distribution – Provides accurate and consistent dosing.

Disadvantages of Syrups:

• High Sugar Content – Unsuitable for diabetic patients unless sugar-free alternatives are used.
• Microbial Growth Risk – Preservatives may be required for stability.
• Viscosity Concerns – Too thick may be hard to pour, too thin may affect throat-coating action.
• Shorter Shelf Life – Prone to crystallization or microbial contamination.
• Solubility Limitations – Some poorly water-soluble drugs require suspensions instead.

Suspensions:

A suspension is a heterogeneous liquid preparation containing finely divided, insoluble drug particles dispersed uniformly in a liquid vehicle. Suspensions are commonly used when the drug is not sufficiently soluble in a solvent and requires appropriate suspending agents, viscosity enhancers, and stabilizers to maintain uniformity and prevent rapid settling. Suspensions must be shaken before administration to ensure proper dosing. As with solutions, other ingredients may be added, such as sweeteners, flavours, and preservatives. Viscosity increasing agents or flocculent enhancers may also be added, which can help with stability. Suspensions are commonly used for oral, topical, ophthalmic, and parenteral drug delivery.

Characteristics of a Well-Formulated Suspension:

• Uniform dispersion – Solid particles remain evenly distributed with minimal settling
• Re-suspendability – Settled particles easily redisperse with gentle shaking
• Proper viscosity – Sufficiently thick to prevent rapid settling but still pourable
• Physical stability – No caking or irreversible sedimentation
• Pleasant taste (for oral suspensions) – Often flavored or sweetened for palatability

Advantages of Suspensions:

• Suitable for Insoluble Drugs – Allows administration of poorly soluble APIs that cannot be formulated as solutions.
• Improved Stability – Some drugs degrade faster in solution; suspensions extend shelf life by reducing drug exposure to solvents.
• Better Taste Masking – Since the drug is not dissolved, bitter tastes can be minimized compared to solutions.
• Flexible Dosing – Can be easily adjusted for different patient needs (e.g., pediatric and geriatric populations).
• Higher Drug Load Possible – Allows for the incorporation of higher drug concentrations compared to solutions.

Disadvantages of Suspensions:

• Physical Instability – Suspensions tend to settle over time and require shaking before administration.
• Risk of Caking – If not properly formulated, solid particles can form hard, compacted sediment that is difficult to redisperse.
• Inconsistent Dosing – If not shaken properly, patients may receive variable drug concentrations in each dose.
• Shorter Beyond-Use Dates (BUDs) – Prone to microbial contamination and chemical degradation, requiring preservatives.
• More Complex Compounding Process – Requires suspending agents, wetting agents, and stabilizers for a uniform and stable preparation.
• Patient must shake the preparation well to ensure proper dose is received.

Examples of Commonly Compounded Suspensions:

• Oral suspensions (e.g., Omeprazole suspension for acid reflux in pediatrics)
• Topical suspensions (e.g., Calamine lotion for soothing skin irritations)
• Ophthalmic suspensions (e.g., Prednisolone acetate eye drops for inflammation)
• Parenteral suspensions (e.g., Dexamethasone sodium injections for inflammation)

Emulsions:

An emulsion is a heterogeneous liquid dosage form consisting of two immiscible liquid phases—one dispersed as droplets (dispersed phase) within another liquid (continuous phase). These two phases are stabilized by an emulsifying agent to prevent separation. Emulsions are commonly used in oral, topical, ophthalmic, and parenteral drug delivery.

Types of Emulsions:

1. Oil-in-Water (O/W) Emulsions

• • Oil droplets dispersed in water
  • More water-soluble
  • Used for oral, intravenous (IV), and topical formulations
  • Example: Milk of magnesia, lotions, creams

2. Water-in-Oil (W/O) Emulsions

• • Water droplets dispersed in oil
  • More oil-soluble
  • Used for topical formulations like ointments and creams
  • Example: Cold creams, emollients

3. Multiple Emulsions (W/O/W or O/W/O)

1. • Complex emulsions with alternating water and oil layers
   • Used for controlled drug release

Components of an Emulsion

• Dispersed Phase (Internal Phase): The liquid in small droplets (e.g., oil in O/W emulsion)
• Continuous Phase (External Phase): The liquid in which droplets are dispersed (e.g., water in O/W emulsion).
• Emulsifying Agents: Surfactants that stabilize the emulsion by reducing interfacial tension.
  • Natural emulsifiers:
    • Acacia (gum arabic)
    • Tragacanth
    • Gelatin
  • Synthetic surfactants:
    • Polysorbates (Tween series) – high HLB, typically for O/W emulsions
    • Sorbitan esters (Span series) – lower HLB, typically for water-in-oil (W/O) emulsions
    • Sodium lauryl sulfate
    • Cetostearyl alcohol
  • Finely divided solids:
    • Bentonite
    • Magnesium hydroxide

Characteristics of a Well-Formulated Emulsion:

• Stable – No phase separation, creaming, or coalescence
• Uniform droplet size – Prevents rapid separation or instability
• Smooth texture – Free from grittiness or excessive thickness
• Palatable (for oral emulsions) – Often flavored and sweetened
• Appropriate viscosity – Sufficiently thick to prevent rapid separation but still pourable or spreadable

Advantages of Emulsions:

• Allows Administration of Lipophilic Drugs – Enables oral and topical delivery of oil-soluble drugs.
• Improved Bioavailability – Enhances drug absorption by increasing the surface area of dispersed droplets.
• Taste Masking – Hides unpleasant tastes of lipophilic drugs in oral emulsions.
• Sustained Drug Release (W/O Emulsions) – Delivers drugs gradually for prolonged effects.

Disadvantages of Emulsions:

• Physical Instability – Prone to phase separation, creaming, coalescence, or breaking.
• Requires Proper Emulsifier Selection – Choosing the wrong surfactant can lead to instability.
• Short Shelf-Life – Emulsions degrade faster than solid or simple liquid dosage forms.
• Complicated Manufacturing Process – Requires high shear mixing or homogenization to ensure stability.

Examples of Commonly Compounded Emulsions:

• Oral emulsions (e.g., Castor oil emulsion as a laxative)
• Topical emulsions (e.g., Moisturizing creams like cold cream)
• Parenteral emulsions (e.g., Propofol emulsion for intravenous anesthesia)
• Ophthalmic emulsions (e.g., Cyclosporine eye drops (Restasis®) for dry eyes)

Emulsion Instability & Prevention 

Emulsions can be unstable. Below is a chart of signs to look for and ways to prevent instability.

Wetting agents:

The Role of Wetting Agents in Pharmacy Compounding

A wetting agent (also called a surfactant) is a pharmaceutical excipient that reduces the interfacial tension between a liquid and a solid, allowing insoluble powders to disperse more easily in a liquid medium. Wetting agents are crucial in suspension, emulsion, and ointment preparation, ensuring uniform dispersion and stability.

Functions of Wetting Agents in Compounding:

• Enhances Dispersion of Insoluble Powders
  • Reduces surface tension between hydrophobic particles and aqueous medium, preventing clumping.
  • Ensures a uniform, homogenous suspension by evenly dispersing drug particles.
• Prevents Aggregation of Particles
  • Minimizes clumping (flocculation) and caking, which improves suspension stability.
  • Increases the bioavailability of the drug by maximizing the surface area exposed to the liquid.
• Improves Drug Absorption
  • Helps drugs dissolve more effectively in biological fluids, leading to better absorption and therapeutic effects.
  • Commonly used in oral, topical, and parenteral formulations.
• Stabilizes Emulsions
  • Works alongside emulsifying agents to ensure the even dispersion of oil and water phases.
  • Prevents coalescence of oil droplets in oil-in-water (O/W) emulsions.
• Aids in Ointment Preparation
  • Helps incorporate powdered drugs into hydrophilic or hydrophobic bases for uniform drug distribution.
  • Essential in levigation, where wetting agents facilitate smooth incorporation of powders into semisolid bases.

Commonly Used Wetting Agents in Compounding:

Flocculating Agents:

Flocculating agents are substances used in suspension formulations to promote the formation of flocs—loosely bound clusters of particles. These flocs prevent individual particles from settling too quickly and forming a hard, difficult-to-redisperse sediment (known as caking).

Role of Flocculating Agents

• Reduce the zeta potential (electrostatic repulsion) between suspended particles.
• Promote controlled aggregation of particles into flocs.
• Improve re-dispersibility—ensuring the suspension can be easily shaken back into a uniform mixture before use.
• Enhance stability of the suspension.

Common Types of Flocculating Agents

Ideal Properties of Flocculating Agents

• Should not form a dense cake but allow easy redispersion.
• Should maintain drug stability and bioavailability.

Should be compatible with other suspension ingredients

Filtering:

• Tablets and most capsules contain the active ingredient as well as excipients.
• Filtering removes particles, impurities, tablet coatings, and excipients.
• Using filter paper
  • Fluting the filter paper increases surface area to which solution is exposed and promotes more rapid filtering
  • Wetting the filter paper with a small amount of liquid that is the solvent of the mixture being filtered minimizes the loss of API (more effective filtering)
• Filtering can only be done when the API is fully dissolved by the solvent – Do not use filtering to remove crystals of undissolved API.

Here are a couple of helpful videos to watch:

How to flute a filter paper

How to filter a solution

Capsules:

Capsules are solid oral dosage forms in which medicinal substances are enclosed in a hard or soft shell. They are a widely used dosage form in compounding because they offer dosing flexibility, improved drug stability, and the ability to mask unpleasant tastes. Capsules are especially useful when a patient requires a non-commercially available dose or combination of drugs.

Key Characteristics of Capsules:

Capsules offer multiple advantages in non-sterile compounding, including precision, patient compliance, and versatility in formulation.

• Flexible Dosing: Capsules can be compounded in a wide range of strengths and combinations, ideal for customized therapy.
• Taste Masking: Capsule shells conceal unpleasant tastes and odors, which improves patient acceptability—particularly useful in pediatric or geriatric care.
• Improved Stability: By reducing exposure to light and air, capsules can help maintain the stability of moisture-sensitive or oxidizable drugs.
• Ease of Administration: Hard gelatin or hydroxypropyl methylcellulose (HPMC) capsules are easy to swallow and do not require the measuring or mixing associated with liquid forms.

Types of Capsules:

Capsules can be classified by their shell material and filling type, depending on the properties of the drug and patient needs.

Hard Shell Capsules:

• Composed of two pieces (body and cap)
• Typically filled with powders or granules
• Can be made with gelatin or a plant-based alternative like hydroxypropyl methylcellulose (HPMC)

Soft Gelatin Capsules:

• One-piece, hermetically sealed capsules filled with liquids, suspensions, or semi-solids
• Not commonly compounded in pharmacies due to equipment limitations, but occasionally available via outsourcing

Modified Capsules (Compounded):

• May contain beadlets, microtablets, or mini-capsules inside a larger shell for combination or delayed-release therapy

Uses of Compounded Capsules:

Compounded capsules are highly versatile and used in many therapeutic contexts:

• Customized Dosing: Ideal for patients who require non-standard doses not commercially available (e.g., thyroid hormones, pediatric doses).
• Combination Therapy: Multiple compatible drugs can be compounded into a single capsule, improving compliance.
• Allergen-Free Formulations: Capsules can be compounded without dyes, lactose, or other excipients that patients may be allergic to or intolerant of.
• Delayed or Targeted Release: While more complex, some compounded capsules include enteric coatings or use special excipients to modify drug release.

Example:

Levothyroxine capsules compounded in custom microgram doses for a patient with thyroid hormone sensitivity who cannot tolerate excipients found in commercial tablets.

2. Topical Compounds

A topical compound is a custom-prepared medication designed for external application to the skin or mucous membranes. It is formulated by a compounding pharmacist or pharmacy technician to meet an individual patient’s specific needs, such as adjusting drug concentration, avoiding allergens, or combining multiple active ingredients that are not commercially available in a single product.

Topical compounds can be prepared in various semi-solid or liquid dosage forms, including:

• Creams – Semi-solid emulsions that provide hydration and moderate occlusion.
• Ointments – Greasy preparations that enhance drug absorption and protect the skin.
• Gels – Water- or alcohol-based formulations that provide rapid absorption.
• Lotions – Fluid emulsions that spread easily over large areas.
• Solutions & Suspensions – Liquid forms used for scalp treatments or wound care.

Topical compounds are commonly used for pain management, dermatological conditions, wound healing, hormone replacement therapy, and transdermal drug delivery

Creams:

Creams are semi-solid emulsions typically consisting of oil and water phases, stabilized with emulsifiers. They are widely used for topical drug delivery due to their smooth texture, ease of spread, and cosmetic acceptability.

Key Characteristics of Creams:

• Emulsion Base:
  • Can be oil-in-water (O/W) or water-in-oil (W/O), depending on the therapeutic need and drug solubility.
• Moderately Hydrating:
  • Provide moisture and a cooling effect without being overly greasy.
• Non-Occlusive:
  • More breathable than ointments, making them suitable for inflamed or weeping skin.
• Good Patient Acceptance:
  • Lightweight, spreads easily, and is absorbed relatively quickly into the skin.

Types of Creams:

• Oil-in-Water (O/W) Creams:
  • Less greasy, water-washable, and more commonly used for daytime application.
• Water-in-Oil (W/O) Creams:
  • More emollient and moisturizing, better for dry skin or nighttime use.

Uses of Compounded Creams:

• Dermatological Conditions:
  • Eczema, psoriasis, and fungal or bacterial infections.
• Hormone Replacement Therapy:
  • Estradiol or progesterone creams for transdermal delivery.
• Cosmeceuticals:
  • Customized formulations for anti-aging or pigmentation.
• Analgesics & Anti-inflammatories:
  • NSAIDs or corticosteroids for localized pain or inflammation.

Creams are ideal when a non-occlusive, moderately moisturizing, and patient-friendly formulation is desired, especially for use on large surface areas or under clothing.

Example: Hydrocortisone 1% cream for eczema.

Ointments:

Ointments are semi-solid preparations intended for external application to the skin or mucous membranes. They have a high proportion of oil-based or hydrophobic components, such as petrolatum, mineral oil, or lanolin, which give them a greasy, occlusive texture.

Ointments can be classified based on their base type:

1. Hydrocarbon (Oleaginous) Bases – Anhydrous, highly occlusive, and best suited for trapping moisture and protecting wounds (e.g., white petrolatum).
2. Absorption Bases – Allow incorporation of small amounts of water while maintaining occlusive properties (e.g., lanolin-based ointments).
3. Water-Removable (Emulsion) Bases – Oil-in-water emulsions that behave like creams but have an ointment consistency (e.g., hydrophilic ointment).
4. Water-Soluble Bases – Non-occlusive and completely water-miscible, making them easy to remove from the skin (e.g., polyethylene glycol (PEG) ointments).

Due to their high lipid content, ointments provide enhanced drug penetration, making them suitable for medications that require prolonged contact with the skin. However, their greasy nature may limit patient acceptability.

Characteristics of Ointments:

• Semi-solid, mainly consisting of hydrophobic substances like petrolatum​
• Occlusive, protective, greasy smooth texture, hard to wash off​
• Water compatible can accept small amounts of water​
• Anhydrous ointments have no water​
• Contain no/little water – longer stability ​
• Wound healing (antibiotic ointments)​
• Delivery of active ingredients​
• Longer stability

• • Example: Antibiotic ointments (e.g., mupirocin) for wound infections.

Gels:

Gels are semi-solid topical preparations composed of a liquid phase thickened with a gelling agent to form a transparent or translucent consistency. They provide rapid drug release and are often preferred for their non-greasy, cooling, and quick-drying properties.

Key Characteristics of Gels:

• Hydrophilic or Lipophilic Base:
  • Can be water-based (hydrogels) or oil-based (organogels), depending on the drug’s solubility and intended absorption.
• Non-Greasy & Fast-Absorbing:
  • Unlike creams and ointments, gels leave minimal residue and penetrate quickly.
• Cooling Effect:
  • Due to their high water content, gels provide a soothing sensation upon application.
• Shear-Thinning Behavior:
  • They spread easily but maintain their structure when at rest, improving stability.

Types of Gels:

1. Hydrogels:
   1. Water-based, lightweight, and commonly used for moisturizing or water-soluble drug formulations.
2. Organogels:
   1. Oil-based or alcohol-based, often used for transdermal drug delivery or medications requiring enhanced skin penetration.
3. Emulsion Gels:
   1. A combination of gel and emulsion properties, allowing for both water- and oil-soluble drugs to be incorporated.

Uses of Compounded Gels:

• Pain Management:
  • Can be formulated with NSAIDs, anesthetics, or muscle relaxants for localized relief.
• Hormone Therapy:
  • Commonly compounded with hormones like testosterone or estradiol for transdermal absorption.
• Dermatological Treatments:
  • Used for acne, fungal infections, and inflammatory skin conditions.
• Antipruritic & Anti-Inflammatory Agents:
  • Gels containing antihistamines or corticosteroids help relieve itching and irritation.

Gels are ideal when a non-greasy, fast-absorbing, and cosmetically elegant formulation is desired, especially for hair-bearing areas or sensitive skin

Example: Diclofenac gel for arthritis pain.

Lotions:

Lotions are liquid or semi-liquid topical preparations designed for external application to the skin. They are typically oil-in-water (O/W) emulsions, though some may be water-in-oil (W/O) emulsions, depending on their intended use. Lotions spread easily over large surface areas, making them ideal for conditions requiring non-greasy, fast-absorbing medication delivery.

Key Characteristics of Lotions:

• Low Viscosity:
  • More fluid than creams or ointments, allowing for easy application and quick absorption.
• Cooling Effect:
  • Due to their water content, lotions provide a refreshing and soothing sensation.
• Non-Greasy & Lightweight:
  • They do not leave a heavy or occlusive residue, making them preferable for hairy areas or skin folds.
• Moisturizing or Medicated:
  • May contain humectants (e.g., glycerin, urea) to retain moisture or active pharmaceutical ingredients (APIs) for therapeutic use.

Uses of Compounded Lotions:

• Dermatological Treatments:
  • Used for eczema, psoriasis, acne, and fungal infections.
• Pain Management:
  • Can be formulated with non-steroidal anti-inflammatory drugs (NSAIDs), anesthetics, or muscle relaxants for targeted relief.
• Hormone Therapy:
  • May contain hormones like estrogen or progesterone for transdermal absorption.
• Anti-Inflammatory & Antipruritic Agents:
  • Often compounded with corticosteroids or antihistamines to reduce itching and inflammation.

Lotions are preferred when a lightweight, easily spreadable formulation is needed, especially for large or sensitive skin areas.

Pastes:

Pastes are semi-solid topical preparations containing a high concentration of finely dispersed powders within a oil or aqueous base. They are thicker, more protective, and less greasy than ointments, making them ideal for applications requiring moisture absorption, adherence, and skin protection.

Key Characteristics of Pastes:

• High Powder Content:
  • Typically contain 20-50% insoluble solids (e.g., zinc oxide, starch, talc) that provide a dry, protective barrier.
• Thick & Stiff Consistency:
  • Less spreadable than creams or ointments, ensuring localized application and reduced drug migration. (which is particularly important if the API is corrosive, such as coal tar or salicylic acid)
• Adheres Well to Skin:
  • Forms a protective layer over wounds, rashes, or inflamed areas, reducing irritation and moisture loss.
• Absorptive Properties:
  • Can absorb exudate, sweat, or moisture, making them useful for weeping skin conditions.

Types of Pastes:

1. Hydrophilic Pastes: Water-based, easier to remove, and preferred for conditions requiring moisture absorption (e.g., zinc oxide pastes).
2. Hydrophobic Pastes: Petrolatum-based, more occlusive, and ideal for protecting the skin from irritants (e.g., diaper rash pastes).

Uses of Compounded Pastes:

• Skin Protection:
  • Commonly used for diaper rash, bedsores, and barrier protection in dermatological conditions.
• Anti-Inflammatory & Wound Healing:
  • Can be compounded with corticosteroids, antimicrobials, or astringents for treating inflamed or infected areas.
• Moisture-Absorbing Applications:
  • Used for weeping eczema, psoriasis, or intertrigo where moisture control is needed.
• Dental Pastes:
  • Formulated for oral ulcers, mucosal protection, or pain relief in conditions like oral lichen planus.

Pastes are ideal when a thick, protective, and long-lasting formulation is required, particularly for localized skin conditions and moisture-sensitive areas.

Understanding the variety and complexity of non-sterile compounded dosage forms is essential for delivering personalized pharmaceutical care. Whether creating an oral liquid for a pediatric patient or preparing a topical formulation for localized pain relief, pharmacy personnel must be equipped with the technical knowledge and critical thinking skills to select appropriate dosage forms, ingredients, and techniques. Each compounded preparation must not only meet patient-specific therapeutic goals but also comply with regulatory and quality assurance requirements.

By mastering the properties, advantages, limitations, and typical uses of common oral and topical dosage forms, pharmacy professionals enhance their ability to prepare customized medications that are safe, stable, effective, and acceptable to patients. This foundational knowledge supports the profession’s commitment to patient-centered care and continuous quality improvement in compounding practice.

Shrewsbury, R. P. (2022). Applied pharmaceutics in contemporary compounding (4th ed.). Morton Publishing Company