What Is a Micelle?

A micelle is an aggregate of surfactant molecules formed in an aqueous solution. Surfactants contain a hydrophilic (water-loving) part and a lipophilic (oil-loving) part.

In a typical micelle, the hydrophilic portions face the surrounding water, while the lipophilic portions are oriented towards the interior of the structure.

How Do Micelles Form?

Micelles begin to form when the concentration of a surfactant in water reaches its critical micelle concentration (CMC). Below this concentration, surfactant molecules are mainly present individually at interfaces or dissolved in the solution.

Above the CMC, additional surfactant molecules increasingly form micelles.

Micelles in Cosmetic Cleansing Products

Micelles are particularly important in cleansing formulations such as:

• Micellar waters
• Facial cleansers
• Makeup removers
• Shampoos
• Other surfactant-based cleansing products

The lipophilic part of the micelle can interact with sebum, makeup, oils and other hydrophobic impurities, while the hydrophilic exterior allows the resulting structure to remain dispersed in water. This helps the impurities to be removed during cleansing.

Micelles and Micellar Water

Micellar water contains surfactants that can form micelles in an aqueous formulation. When applied to the skin with a cotton pad, the micellar structures can interact with oils and other impurities and help lift them from the skin surface.

The cleansing performance and sensory properties depend on the type and concentration of surfactants used in the formulation.

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What Is a Lipid?

A lipid is a broad group of naturally occurring substances characterised by their limited solubility in water and generally good solubility in organic solvents. Lipids include fats, oils, waxes, fatty acids, phospholipids, sterols and ceramides.

They are important components of biological structures, including cell membranes and the lipid matrix of the skin's outermost layer.

Lipids in the Skin

Lipids are an important part of the stratum corneum, where they contribute to the organisation of the skin barrier. Key skin lipids include ceramides, cholesterol and free fatty acids.

The composition and organisation of these lipids influence the barrier properties of the skin and its ability to limit water loss.

Lipids in Cosmetic Formulation

Cosmetic formulations use a wide variety of lipid ingredients, including:

• Vegetable oils and butters
• Fatty acids and fatty alcohols
• Waxes
• Esters
• Ceramides
• Phospholipids
• Cholesterol and other sterols

Depending on their chemical structure and properties, lipids can provide emolliency, lubrication, texture, occlusivity and skin conditioning.

Lipids and Skin Conditioning

Lipid ingredients can help improve the feel and appearance of the skin by supporting its surface properties and providing a smoother, softer feel. They are therefore commonly used in creams, lotions, balms, cleansing products and other skincare formulations.

What Is a Humectant?

A humectant is a substance that has the ability to attract and retain water. In cosmetic formulations, humectants are primarily used to support the water content of the skin or hair and improve the moisturising properties of a product.

Common cosmetic humectants include glycerin, propylene glycol, sorbitol, urea and hyaluronic acid.

How Do Humectants Work?

Humectants interact with water and help maintain moisture within the formulation and, depending on the ingredient and application, within the outer layers of the skin or hair.

Their effectiveness depends on factors such as the concentration used, the formulation, environmental conditions and the combination with other moisturising ingredients.

Humectants in Cosmetic Formulation

Humectants are commonly incorporated into:

• Moisturisers and creams
• Facial serums
• Cleansers
• Body lotions
• Shampoos and conditioners
• Hair treatments
• Masks

They are often combined with emollients and occlusive ingredients. While humectants help attract and retain water, emollients improve skin feel and smoothness, while occlusives help reduce water loss from the skin surface.

Humectant vs. Moisturiser

A humectant is a type of moisturising ingredient, but the terms are not interchangeable. A moisturising product may contain several types of ingredients that work together to improve skin hydration and reduce moisture loss.

What Is an Emulsifier?

An emulsifier is a substance that helps form and stabilise an emulsion by reducing the interfacial tension between two immiscible phases, typically oil and water.

Without a suitable emulsifier system, the two phases tend to separate. The emulsifier helps maintain a more uniform and stable distribution of one phase within the other.

How Do Emulsifiers Work?

Emulsifiers contain molecules with different affinities for oil and water. During emulsification, they become positioned at the interface between the two phases and help prevent the dispersed droplets from coming together and separating.

The choice of emulsifier depends on factors such as:

• Type of emulsion, such as oil-in-water (O/W) or water-in-oil (W/O)
• Required stability
• Oil phase composition
• Desired texture and sensory properties
• Processing conditions
• Other ingredients in the formulation

Types of Emulsifiers

Cosmetic formulations can use different types of emulsifiers, including:

• Non-ionic emulsifiers
• Anionic emulsifiers
• Cationic emulsifiers
• Polymeric emulsifiers
• Natural and naturally derived emulsifiers

Non-ionic emulsifiers are widely used in cosmetic formulations because of their compatibility with many other ingredients.

Emulsifiers in Cosmetic Products

Emulsifiers are commonly used in:

• Face and body creams
• Lotions
• Cleansing creams
• Sunscreen formulations
• Hair conditioners
• Cosmetic milks
• Makeup products

The emulsifier system has a significant influence on the stability, texture, appearance and sensory properties of the finished product.

Emulsifier vs. Surfactant

Emulsifiers are a type of surfactant, but not all surfactants are used primarily as emulsifiers. Surfactants can also perform functions such as cleansing, foaming, wetting and solubilisation.

References

Cosmetic Formulation Principles and Practice - Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

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What Is a Detergent?

A detergent is a substance that assists in removing unwanted materials from a surface, particularly oily or water-insoluble substances. Detergents are generally associated with surfactants, which reduce surface tension and help disperse oils and dirt in water.

When a detergent-containing product is rinsed away, the surfactant system helps carry the removed impurities away with the water.

Detergents in Cosmetic Products

In cosmetics and personal care products, detergents are primarily used for cleansing. They can be found in formulations such as:

• Shampoos
• Shower gels and body washes
• Facial cleansers
• Liquid soaps
• Hand washes
• Other rinse-off cleansing products

Different surfactants can be selected depending on the desired cleansing performance, foam characteristics, mildness and sensory properties of the finished product.

Detergent and Surfactant

The terms detergent and surfactant are closely related but are not completely interchangeable. A surfactant is a broader category of substances that can perform functions such as cleansing, emulsification, solubilisation, wetting and foaming. Detergents are generally surfactant-based systems designed primarily for cleansing.

Detergents in Cosmetic Formulation

The choice and concentration of detergents are important in developing a cleansing product. The formulation needs to provide the required cleansing performance while maintaining the desired skin or hair feel and overall product characteristics.

What Does In Vivo Mean?

In vivo means “within the living” and describes studies performed in a living organism rather than in an isolated laboratory system.

In cosmetic research, in vivo testing may involve controlled studies with human volunteers to assess characteristics such as skin hydration, skin elasticity, transepidermal water loss (TEWL), product efficacy or skin tolerability.

In Vivo Methods in Cosmetics

In vivo studies can provide information about how a cosmetic product performs under conditions that more closely represent its intended use. Depending on the study design, measurements may be taken before and after product application and compared with baseline or control measurements.

Examples include studies evaluating:

• Skin hydration
• Skin barrier properties
• Skin elasticity
• TEWL
• Appearance of fine lines and wrinkles
• Product tolerability

In Vivo vs. In Vitro

The main difference is where the study is performed:

• In vivo: within a living organism, such as a human volunteer.
• In vitro: outside a living organism, using isolated cells, tissues or other biological materials.

Both approaches can provide useful information, and the appropriate method depends on the specific objective of the study.

What Does In Vitro Mean?

In vitro literally means “in the glass” and refers to tests performed outside a living organism under controlled laboratory conditions.

In vitro studies commonly involve isolated cells, tissues, organs or biological components rather than testing directly on a living person or animal.

In Vitro Methods in Cosmetics

In vitro methods can be used during cosmetic product development to investigate the properties, performance or safety of ingredients and finished products. Depending on the purpose of the test, they may provide information about biological responses or specific product characteristics under controlled laboratory conditions.

They are an important part of modern cosmetic research and laboratory testing and can complement other testing methods used during product development.

In Vitro vs. In Vivo

The main difference is where the test is performed:

• In vitro: outside a living organism, using isolated biological material.
• In vivo: performed within a living organism.

The choice of method depends on the purpose of the study and the information required.

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What Is a Contract Manufacturer?

A contract manufacturer is a manufacturer outside your company that is contracted to produce a cosmetic product for you. The manufacturer may produce products according to an agreed formulation, specification, packaging format and production quantity.

Using a contract manufacturer allows cosmetic brands to outsource production without establishing and operating their own manufacturing facilities.

Why Use a Contract Manufacturer?

Companies may work with contract manufacturers when they do not have the capability to produce their own products. This can include situations where a company lacks:

• Manufacturing facilities
• Production equipment
• Suitable production capacity
• Technical manufacturing expertise
• Resources for larger-scale production

Contract Manufacturing in Cosmetic Product Development

In cosmetic product development, a contract manufacturer may be responsible for manufacturing the finished product according to the approved formulation and agreed specifications. Depending on the project, manufacturing may also involve filling, packaging and other production activities.

The selection of a suitable contract manufacturer is an important part of bringing a cosmetic product from development to commercial production.

What Is a Project Schedule?

A project schedule represents the planned timing of project activities. It shows when activities are expected to start and finish and can also illustrate the relationships and dependencies between them.

A schedule can be developed at different levels of detail depending on the size, complexity and requirements of the project.

Key Elements of a Project Schedule

A project schedule may include:

• Activities – the work that needs to be completed.
• Start and finish dates – when each activity is planned to begin and end.
• Duration – the expected time required for an activity.
• Dependencies – relationships between activities that determine their sequence.
• Milestones – significant points or events in the project.
• Progress – the actual status of activities compared with the plan.

Project Schedule in Cosmetic Product Development

In cosmetic product development, a schedule can be used to coordinate activities such as formulation development, sample preparation, client feedback, testing, packaging development, regulatory documentation and production.

A well-defined schedule helps project participants understand the expected sequence of activities and identify potential delays or dependencies that may affect the overall project timeline.

References

The Standard for Project Management and A Guide to the Project Management Body of Knowledge (PMBOK® Guide), Seventh Edition.

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What Is Project Scope?

Project scope is the sum of the products, services and results to be provided as part of a project. It describes the boundaries and intended deliverables of the project and helps establish what the project is expected to accomplish.

As the scope is defined, additional requirements may need to be identified. The level of detail and certainty can therefore vary depending on the nature of the project.

How Can Project Scope Develop?

Project scope does not always have to be completely defined at the beginning of a project. Depending on the project and the available information, the scope can:

• be clearly defined at the start;
• evolve as the project progresses; or
• be progressively discovered during the project.

Changes or further clarification of the scope may lead to additional requirements and adjustments to project activities.

Project Scope in Cosmetic Product Development

In cosmetic product development, project scope may define the products to be developed, formulation work, packaging, testing, regulatory activities, production requirements and other agreed deliverables.

A clearly established scope helps project participants understand what is included in the development project and provides a framework for managing requirements, timelines and responsibilities.

References

The Standard for Project Management and A Guide to the Project Management Body of Knowledge (PMBOK® Guide), Seventh Edition.

What Are Stakeholders?

Stakeholders can be individuals, groups or organisations that have an interest in a project or may influence or be affected by its activities and outcomes. Their influence can be either positive or negative.

Stakeholders may include clients, project team members, suppliers, regulatory authorities, manufacturers, laboratories, investors and other parties involved in or affected by the project.

How Can Stakeholders Affect a Project?

Stakeholders can influence many aspects of a project, including:

Scope and Requirements
They may introduce, modify or remove project requirements.

Schedule
They can help accelerate activities or cause delays to important project stages.

Cost
They may reduce planned expenditure or introduce additional requirements and resources.

Project Team
They can influence access to the people, knowledge and expertise required to deliver the project.

Quality
Stakeholders may define or require specific quality standards.

Risk
They can influence risk thresholds and participate in risk management activities.

Outcomes and Benefits
They can enable or prevent activities required to achieve the intended outcomes and help define the value the project is expected to deliver.

Stakeholder Engagement

Stakeholders can change throughout the project lifecycle. Their level of interest, influence and impact can also change over time.

Effective stakeholder engagement helps the project team understand stakeholders' interests, concerns and expectations and address them throughout the project. This is particularly important for stakeholders with significant influence over the project.

Stakeholders in Cosmetic Product Development

A cosmetic product development project can involve many different stakeholders, including the brand owner, formulators, packaging suppliers, testing laboratories, manufacturers, regulatory specialists and other service providers.

Coordinating these stakeholders and maintaining effective communication between them is an important part of managing a cosmetic development project.

References

The Standard for Project Management and A Guide to the Project Management Body of Knowledge (PMBOK® Guide), Seventh Edition.

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What Is a Gantt Chart?

A Gantt chart is a type of bar chart used to illustrate a project schedule. Project activities are listed alongside a horizontal timeline, with each task represented by a bar showing its planned start date, duration and end date.

Gantt charts provide a visual overview of how different activities fit together within a project and can help project teams understand the overall project schedule.

Key Elements of a Gantt Chart

A typical Gantt chart can include:

Tasks and Activities
The individual activities that need to be completed as part of the project.

Timeline
The calendar period over which the project activities are planned.

Duration
The amount of time allocated to each task.

Dependencies
Relationships between activities showing when one task depends on another being completed or started.

Milestones
Important events or achievements within the project that have no significant duration.

Progress
An indication of how much of a task or project has been completed.

Why Use a Gantt Chart?

Gantt charts make complex project schedules easier to understand by presenting activities and timing in a single visual overview. They can help project teams:

• Plan project activities
• Establish realistic timelines
• Identify task dependencies
• Coordinate different workstreams
• Monitor project progress
• Identify potential delays

Gantt Charts in Cosmetic Product Development

Gantt charts can be particularly useful for cosmetic product development projects, where formulation, testing, packaging, regulatory activities and manufacturing often need to be coordinated.

For example, a project schedule may show formulation development, sample evaluation, revisions, stability testing, packaging procurement, regulatory documentation and production as interconnected activities. This allows the project team to see how delays in one activity may affect subsequent stages.

References

The Standard for Project Management and A Guide to the Project Management Body of Knowledge (PMBOK® Guide), Seventh Edition.

What Is a Project Manager?

A Project Manager is the person assigned by the performing organisation to lead the project team responsible for achieving the project objectives. Project Managers perform a variety of functions, including facilitating project team activities and managing the processes required to deliver the intended outcomes.

What Does a Project Manager Do?

Project Managers help coordinate the collective work required to deliver a project effectively and efficiently. Their responsibilities can include:

• Coordinating project team activities
• Supporting communication between team members and stakeholders
• Facilitating the work needed to achieve project outcomes
• Managing project processes
• Supporting the delivery of project benefits and value

The specific functions of a Project Manager can vary depending on the project, organisation, industry and required deliverables.

Project Coordination

Not every project requires the same coordination structure. Some projects benefit from centralised coordination through a designated Project Manager, while others may use decentralised coordination where project team members self-organise and self-manage.

A project can also combine both approaches, with self-organised teams responsible for specific parts of the work while overall coordination remains centralised.

Project Manager in Cosmetic Product Development

In cosmetic product development, a Project Manager may coordinate activities involving formulation, packaging, testing, manufacturing, regulatory compliance and other specialist functions. The role helps ensure that the different contributors work together towards the agreed project objectives.

Ultimately, project outcomes are delivered through the collective effort of the project team, supported by appropriate coordination and leadership.

References

The Standard for Project Management and A Guide to the Project Management Body of Knowledge (PMBOK® Guide), Seventh Edition.

What Is Project Management?

Project management is the application of knowledge, skills, tools and techniques to project activities to meet project requirements. It involves guiding and coordinating project work to achieve the intended outcomes.

Project teams can use different approaches depending on the nature and requirements of the project, including predictive, hybrid and adaptive approaches.

Project Management in Cosmetic Product Development

Cosmetic product development often involves multiple interconnected activities, including formulation, testing, packaging, regulatory compliance, production and marketing. Project management helps coordinate these activities, establish timelines, manage dependencies and ensure that the different parts of the development process progress towards the intended outcome.

Effective project management also helps coordinate communication between clients, formulators, laboratories, packaging suppliers, manufacturers and regulatory specialists.

Why Is Project Management Important?

A structured project management approach helps teams coordinate resources, activities and stakeholders throughout a project. It provides a framework for guiding the work from the initial requirements through to the intended project outcome.

References

The Standard for Project Management and A Guide to the Project Management Body of Knowledge (PMBOK® Guide), Seventh Edition.

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What Is a Project?

A project is a temporary endeavour undertaken to create a unique product, service or result. The temporary nature of a project means that the project work, or a specific phase of the work, has a defined beginning and end. Projects can operate independently or form part of a programme or portfolio.

Project Complexity

A project is a system made up of elements that interact with one another. Complexity is a characteristic of a project or its environment that can make the project difficult to manage.

Complexity can arise from the interactions between project elements, people, systems and the wider project environment. Risks, dependencies, events and relationships can interact in ways that are difficult to predict or isolate.

What Influences Project Complexity?

Project complexity can increase with the number and diversity of stakeholders involved. For example, regulatory agencies, international financial institutions, multiple suppliers, specialist subcontractors and local communities can each influence a project's complexity.

Project teams may not always be able to foresee how these interactions will develop. However, they can adapt their activities to address the effects of complexity as they emerge.

Projects in Cosmetic Product Development

In cosmetic product development, a project may involve multiple interconnected activities such as formulation, packaging, testing, regulatory compliance, production and marketing. Coordinating these activities and the different stakeholders involved is an important part of successful project management.

References

The Standard for Project Management and A Guide to the Project Management Body of Knowledge (PMBOK® Guide), Seventh Edition.

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What Is Polystyrene (PS)?

Polystyrene (PS) is a plastic material used in a range of cosmetic packaging applications. Its properties make it particularly suitable for packaging decorative cosmetics and compact products.

Cosmetic Packaging Applications

Polystyrene is commonly used for packaging:

• Make-up products
• Lipsticks
• Compact powders
• Blush
• Eyeshadows
• Cosmetic covers

Its use is particularly associated with decorative cosmetics where rigid, shaped packaging components are required.

Ingredient Information

Material: Polystyrene (PS)
CAS: 9003-53-6
EINECS/EC: 500-008-9

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

What Is Polypropylene (PP)?

Polypropylene (PP) is a translucent plastic resin commonly used for cosmetic packaging. Compared with polyethylene (PE), PP has lower porosity, which reduces the potential migration of product components through the packaging.

Cosmetic Packaging Applications

PP is commonly used for:

• Shampoo and conditioner bottles
• Cream jars
• Bath oils
• Sun tanning oils
• Other products containing high concentrations of vegetable or mineral oils

Its lower porosity makes it particularly useful for packaging formulations containing significant amounts of oils.

PP Closures and Lids

Polypropylene is also widely used for cosmetic packaging closures. It is commonly used to manufacture:

• Flip-top lids
• Top-disc closures
• Blind covers
• Discs placed under cream jar lids to prevent direct contact between the product and the lid

Ingredient Information

Material: Polypropylene (PP)
CAS: 9003-07-0

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

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What Is Polyvinyl Chloride (PVC)?

Polyvinyl Chloride, commonly abbreviated as PVC or V, is a plastic packaging material that offers good transparency. However, it is relatively brittle and has little memory, meaning it does not readily return to its original shape after deformation. As a result, PVC packaging can crack or break if dropped.

Key Properties of PVC

Transparency
PVC can provide clear packaging, making it suitable where visibility of the cosmetic product is desired.

Limited Flexibility
Compared with more flexible packaging materials, PVC has little memory and is more susceptible to cracking or breaking when subjected to impact.

Colour Options
PVC can be coloured using pigments, allowing different packaging appearances to be created.

Cosmetic Packaging Applications

PVC is commonly used for:

• Shampoo bottles
• Conditioner bottles
• Lotion bottles
• Mascara tubes
• Lip gloss packaging

Its transparency and ability to be coloured make it suitable for a variety of cosmetic packaging designs.

Ingredient Information

Material: Polyvinyl Chloride (PVC or V)
CAS: 9002-86-2
EINECS/EC: 618-338-8

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

What Is High-Density Polyethylene (HDPE)?

HDPE is a non-transparent plastic resin commonly used for cosmetic packaging. Its opaque appearance makes it particularly suitable for products where transparent packaging is not required.

Cosmetic Packaging Applications

HDPE is widely used for:

• Shampoo bottles
• Conditioner bottles
• Lotion bottles
• Sunscreen bottles

HDPE packaging can be modified with pigments to create different colours. Pearl pigments can also be added to produce a pearlescent appearance.

Packaging Appearance

Depending on the desired brand identity and product presentation, HDPE can be manufactured in:

White: A common appearance for cosmetic packaging.

Coloured: Pigments can be incorporated to create a wide range of colours.

Pearlescent: Pearl pigments can provide a distinctive pearlescent finish.

Ingredient Information

Material: High-Density Polyethylene (HDPE)
CAS: 9002-88-4
EINECS/EC: Not specified

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

What Is Polyethylene Terephthalate (PET)?

Polyethylene Terephthalate (PET) is a widely used packaging material known for its transparency, flexibility and memory, meaning its ability to return towards its original shape after deformation. It also has good compatibility with most cosmetic ingredients.

Key Properties of PET

Transparency and Flexibility
PET can provide clear packaging while maintaining sufficient flexibility for everyday cosmetic use.

Durability
Its good durability makes PET particularly suitable for transparent shampoo and conditioner bottles. When dropped, the bottle can dent rather than crack, providing an advantage over some other transparent resins.

Colour and Appearance Options
Pigments can be added to PET to create coloured, transparent or translucent packaging. Titanium dioxide can produce completely white packaging, while mica-based pearlescent pigments can create a pearlescent appearance.

Light Protection
The addition of sunscreen to the resin can provide protection from light for the packaged product while maintaining packaging transparency.

Cosmetic Packaging Applications

PET is commonly used for:

• Shampoo and conditioner bottles
• Cosmetic bottles
• Cosmetic pots and containers
• Transparent packaging
• Coloured, translucent or opaque packaging

Its combination of transparency, durability and design flexibility makes PET a versatile material for cosmetic packaging.

Ingredient Information

Material: Polyethylene Terephthalate (PET)
CAS: 25038-59-9
EINECS/EC: 607-507-1

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

What Is Phenoxyethanol?

Phenoxyethanol is a broad-spectrum preservative used extensively in cosmetic formulations. It is effective against a wide range of microorganisms, although it is slightly less effective against Gram-positive bacteria than against some other microbial species.

Phenoxyethanol is slightly water-soluble, with a solubility of approximately 2.4%. It is preferably added to formulations at temperatures below 40°C to reduce the possibility of evaporative loss. Significant loss is generally only a concern when a manufactured batch is maintained at temperatures above 80°C for a prolonged period.

Key Properties of Phenoxyethanol

Broad-Spectrum Preservation
Phenoxyethanol provides broad-spectrum antimicrobial protection and is widely used as part of cosmetic preservation systems.

Broad pH Range
It retains its preservative activity across approximately pH 3–9.

Combination with Other Preservatives
Phenoxyethanol is commonly used together with other preservatives and is rarely used as the sole preservative in a formulation.

Cosmetic Applications

Phenoxyethanol is used as a preservative in a wide range of cosmetic formulations. Typical use concentrations are 0.4–1.0%, depending on the formulation and applicable regulatory requirements.

It is permitted in most territories, subject to specific regulatory restrictions.

Ingredient Information

INCI: Phenoxyethanol
CAS: 122-99-6
EINECS/EC: 204-589-7

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

What Is Diazolidinyl Urea?

Diazolidinyl Urea is primarily an antibacterial preservative, with activity against moulds but relatively weak anti-yeast activity. It has been widely used in cosmetic formulations since its introduction in the 1980s and is classified as a formaldehyde donor.

It is highly water-soluble and should be added to formulations at temperatures below 40°C to minimise decomposition. It remains active across a broad pH range of approximately pH 3–9.

Key Properties of Diazolidinyl Urea

Antibacterial Activity
Its primary preservative activity is directed against bacteria, with additional activity against moulds.

Water Solubility
Its high water solubility makes it suitable for aqueous cosmetic formulations.

Broad pH Range
Diazolidinyl Urea retains its preservative activity over approximately pH 3–9.

Heat Sensitivity
It should be incorporated below 40°C to reduce the risk of decomposition.

Cosmetic Applications

Diazolidinyl Urea is used as a preservative in a wide range of cosmetic formulations. The typical use concentration stated by A&T Formulation is 0.1–0.3%. Its use is permitted in many territories, subject to applicable regulatory restrictions.

Ingredient Information

INCI: Diazolidinyl Urea
CAS: 78491-02-8
EINECS/EC: 278-928-2

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

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What Is Imidazolidinyl Urea?

Imidazolidinyl Urea is primarily an antibacterial preservative with very limited antifungal activity. It has been widely used in cosmetic products since its introduction in the 1980s.

It is highly water-soluble and should be added to cosmetic formulations at temperatures below 40°C to minimise decomposition. It remains active across a relatively broad pH range of approximately pH 3–9.

Key Properties of Imidazolidinyl Urea

Antibacterial Activity
Imidazolidinyl Urea is primarily effective against bacteria, while its antifungal activity is limited.

Water Solubility
Its high water solubility makes it particularly suitable for aqueous cosmetic formulations.

Broad pH Stability
It retains preservative activity across a pH range of approximately 3–9.

Heat Sensitivity
The ingredient should be incorporated below 40°C to avoid decomposition.

Cosmetic Applications

Imidazolidinyl Urea can be used as a preservative in a variety of cosmetic formulations. Typical use concentrations are approximately 0.2–0.5%, depending on the formulation and applicable regulatory requirements.

Formulation Considerations

One consideration associated with Imidazolidinyl Urea is its potential to release very low levels of formaldehyde. This characteristic is considered a disadvantage by some formulators and consumers.

Its use is subject to regulatory restrictions in different markets, so the applicable requirements should always be checked for the intended product and market.

Ingredient Information

INCI: Imidazolidinyl Urea
CAS: 39236-46-9
EINECS/EC: 254-372-6

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

What Are Esters?

Esters are the products of the reaction between an acid, usually an organic acid, and an alcohol. In cosmetic formulations, a wide range of esters can be produced by combining different fatty acids with different alcohols.

Common fatty acids used to produce cosmetic esters include:

• Caprylic acid
• Capric acid
• Lauric acid
• Myristic acid
• Palmitic acid
• Stearic acid
• Oleic acid
• Linoleic acid
• Behenic acid
• Adipic acid

Common alcohols include isopropyl alcohol, n-butyl alcohol, ethylhexyl alcohol, myristyl alcohol and oleyl alcohol, as well as polyvalent alcohols such as ethylene glycol, polyglycerol, propylene glycol and glycerol.

Esters in Cosmetic Formulation

The large number of possible combinations of acids and alcohols allows the cosmetic industry to produce a wide range of synthetic esters. Their different chemical structures allow formulators to select esters according to the desired properties of a cosmetic formulation.

Esters are therefore widely used as functional ingredients in cosmetic products where specific formulation and sensory characteristics are required.

Ingredient Information

CAS: Not applicable – esters represent a broad group of compounds rather than a single substance
EINECS/EC: Not applicable – depends on the specific ester

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

What Is Mineral Oil?

Mineral Oil refers to highly refined liquid hydrocarbons derived from petroleum distillates. Other commonly used names include liquid petrolatum, liquid paraffin, paraffin oil, white oil and white mineral oil.

Medium- and low-viscosity mineral oils are produced through several refining processes, including distillation, extraction and crystallisation, followed by purification using acid treatment and/or hydrotreatment. They consist mainly of highly refined paraffinic and naphthenic liquid hydrocarbons with boiling points above 200°C.

Key Properties of Mineral Oil

Lightweight and Odourless
Mineral oils used in cosmetics are lightweight and are generally odourless and tasteless.

Highly Refined
Cosmetic-grade mineral oils undergo extensive refining and purification to achieve the required quality for cosmetic applications.

Versatile Cosmetic Ingredient
Mineral Oil is compatible with a wide range of cosmetic formulations and is particularly common in emollient and protective products.

Cosmetic Applications

Mineral Oil is commonly used in:

• Baby lotions
• Cold creams
• Ointments
• Skincare products
• Make-up removers
• Products designed to condition eyelashes

It can also be used for removing make-up and temporary tattoos.

Ingredient Information

INCI: Paraffinum Liquidum
CAS: 8042-47-5
EINECS/EC: 232-455-8

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

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What Is Ozokerite Wax?

Ozokerite Wax is generally a white, crystalline, odourless and tasteless solid. It is most often produced from blends of paraffin and microcrystalline waxes. When combined, these waxes can provide broader functionality than the individual components.

Key Properties of Ozokerite Wax

Viscosity and Structure
Ozokerite Wax can increase viscosity and improve the structure of cosmetic formulations.

Emulsion Stability
It can assist in improving the stability of emulsions and contribute to the physical consistency of the finished product.

Gel Strength
The wax enhances gel strength in liquid and semi-solid systems, making it useful where a firmer structure is required.

Hardness and High Melting Point
Ozokerite is a hard wax with a relatively high melting point, making it particularly suitable for solid cosmetic products.

Cosmetic Applications

Ozokerite Wax is commonly used in:

• Lipsticks
• Lip balms and other lip care products
• Liquid and semi-solid cosmetic formulations
• Other formulations where increased viscosity and structure are required

In lipsticks and lip care products, it helps provide structure and improves stick strength.

Ingredient Information

INCI: Ozokerite

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

What Is Microcrystalline Wax?

Microcrystalline Wax is a solid obtained by extracting the oil from petrolatum. It is a complex mixture composed mainly of C31–C70 isoparaffins and has a characteristic microcrystalline structure.

Key Properties of Microcrystalline Wax

High Adhesive Power
Microcrystalline Wax has good adhesion, making it useful in formulations where strong binding and cohesion are required.

Good Extensibility
It provides good extensibility and contributes to the texture and application properties of cosmetic products.

Low-Temperature Stability
Microcrystalline Wax is not particularly susceptible to low temperatures, helping maintain the physical properties of formulations under different storage conditions.

High Melting Point
Its melting point is approximately 60–85°C, depending on its composition and grade.

Cosmetic Applications

Microcrystalline Wax is commonly used in:

• Lipsticks
• Creams
• Other wax-containing cosmetic formulations

When combined with other waxes, it can suppress crystal formation and help produce a smoother and more homogeneous formulation.

Ingredient Information

INCI: Microcrystalline Wax
CAS: Not specified on the original A&T Formulation page
EINECS/EC: Not specified on the original A&T Formulation page

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.

What Is Rice Bran Wax?

Rice Bran Wax is a vegetable wax derived from rice bran. Its main components are long-chain wax esters with chain lengths of approximately C60. Although its chemical composition is similar to sunflower wax, its formulation applications are quite different.

Key Properties of Rice Bran Wax

Highly Hydrophobic
Refined Rice Bran Wax has a strongly hydrophobic character, making it suitable for oil-based cosmetic formulations.

Soft Oil Gels
Unlike some harder vegetable waxes, Rice Bran Wax forms soft oil gels. This property makes it particularly useful where a softer and more flexible texture is required.

Long-Chain Wax Esters
Its main components are long-chain wax esters, with chain lengths of around C60.

Cosmetic Applications

Rice Bran Wax is particularly suitable for:

• Mascaras
• Skincare emulsions
• Oil-based cosmetic formulations
• Products where soft oil-gel structures are desired

Its ability to form soft oil gels makes it especially useful in mascara and skincare formulations.

Ingredient Information

INCI: Oryza Sativa Bran Wax

References

Cosmetic Formulation Principles and Practice – Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters.