Excipients

This category includes products intended for manufacturers of medicines, dietary supplements, dermocosmetics and medical devices who are seeking reliable, reproducible and well-characterised excipients for the formulation of their products.

What are excipients in medicines and dietary supplements?

What are excipients and why do they play such a vital role in the pharmaceutical industry?

Excipients – referred to as ‘excipients’ in English terminology – are any components of medicinal products or cosmetics other than the active pharmaceutical ingredient (API). They are not added to produce a therapeutic effect; their purpose is to enable the manufacture of a product with the desired form, stability and performance characteristics. Excipients must meet stringent quality standards and must not affect the human body at the doses used.

Key functions of excipients in drug manufacturing

Excipients play a number of key roles in drug formulation technology.

• They enable the drug to be formulated into the correct dosage form – without suitable fillers, carriers and binders, it would not be possible to produce a tablet with the correct hardness and disintegration profile, a capsule with a controlled volume or a syrup with the appropriate viscosity.
• They ensure physicochemical stability – stabilisers, antioxidants and preservatives protect the active substance from degradation caused by factors such as moisture, oxygen, light and temperature. Appropriately selected excipients therefore determine, among other things, the physical properties of the medicinal product and increase the drug’s shelf life.
• They control the release profile – appropriately selected polymers and matrices enable both immediate and sustained release of the active substance, which directly translates into therapeutic efficacy and patient comfort. They therefore regulate the rate of release of the active substance. In the case of sustained-release tablets, excipients are essential for ensuring a constant concentration of the active substance in the body over a longer period.
• They influence bioavailability – solubilizers, emulsifiers and wetting agents can significantly increase the solubility and absorption of a medicinal substance with poor water solubility (BCS classes II and IV).
• They improve the acceptability of the formulation – flavourings, sweeteners, colourants and masking agents (e.g. to mask an unpleasant taste) influence patient preference, particularly in paediatrics and geriatrics. Colourants, in turn, give medicines a distinctive appearance, making them easier to identify.

Excipients in tablets, capsules, syrups, injectable solutions or creams are therefore not “meaningless fillers” – they are precisely selected ingredients that contribute to the quality, efficacy and safety of the finished preparation.

Similarly, excipients in dermocosmetics perform essential technological functions: they stabilise emulsions, regulate consistency, ensure adequate skin hydration, facilitate the absorption of active ingredients and extend the product’s shelf life.

Excipients in food supplements are subject to food regulations. Food supplements in the form of tablets, capsules, powders and suspensions require excipients to ensure appropriate dose uniformity, stability and shelf life of the product.

Classification of excipients by function – an overview

Excipients can be classified in many ways – by chemical structure, the product form in which they are used, or – most practically – by the function they perform in the formulation. Below is an overview of excipients by their main functions, as available in the PCC Group’s product range.

Solvents

A pharmaceutical solvent is a liquid used during the manufacture or preparation of medicines, the purpose of which is to dissolve or dilute active substances. The appropriate selection of such a solvent plays a significant role, as it affects the stability, bioavailability and efficacy of the final medicinal product. Polyethylene glycols from the PCC range – POLIkol 300EXC, POLIkol 400EXC and POLIkol 600EXC – belong to the group of commonly used solvents.

Solubilisers

Their main function is to increase the solubility of active substances in aqueous or mixed media. They help to address the issue of low bioavailability of active substances classified as BCS Class II and IV, which require special formulation techniques.

The mechanism of action of solubilisers involves the formation of micelles, microemulsions or inclusion complexes, which ‘envelop’ the molecule of the lipophilic active ingredient and enable its transfer into an aqueous solution.

The selection of an appropriate solubiliser requires an analysis of the active substance’s properties and the safety requirements for the specific route of administration.

Emulsifiers

Emulsifiers stabilise two-phase liquid/liquid systems (O/W or W/O emulsions). Their role is to reduce the interfacial tension at the oil-water interface. The classic selection of an emulsifier for an emulsion formulation is based on the HLB (Hydrophilic-Lipophilic Balance) concept. Correctly matching the HLB value of the emulsifier or mixture of emulsifiers to the required HLB of the oil phase is key to obtaining a stable and durable emulsion.

Humectants

Humectants are excipients capable of binding and retaining water, both within the formulation (ensuring its stability under varying humidity) and in the skin or mucous membranes (moisturising effect). In cosmetic and dermatological formulations, humectants are a key group of functionally active ingredients.

Polyethylene glycols from the PCC range – POLIkol 300EXC, POLIkol 400EXC and POLIkol 600EXC – used in cosmetic formulations (creams, lotions, toners) improve skin hydration and prevent the product from drying out.

Softening agents (plasticisers)

Plasticisers are excipients that lower the glass transition temperature (Tg) of polymers used in tablet film coatings, capsule matrices or controlled-release system membranes. Their role is to increase the flexibility of the coating, prevent it from cracking and improve adhesion to the tablet core.

Wetting agents

Wetting agents, i.e. surfactants with wetting properties, reduce the contact angle of solid active ingredients and granules with water or biologically relevant media. Their use is particularly important during granulation or tableting.

Formulation stabilisers

Formulation stabilisers are excipients that protect a multi-component system (formulation) against physicochemical degradation – coalescence, sedimentation, hydrolysis, oxidation or phase separation. Formulation stabilisation is one of the key challenges in drug and cosmetic formulation technology.

Antistatic agents

Electrostatic charges are a significant problem in pharmaceutical manufacturing, particularly when working with powders and granules. They can cause mixture heterogeneity, dosing problems and cross-contamination. Antistatic agents (antistats) neutralise or limit the accumulation of electrostatic charges on the surface of particles.

In powder and tablet formulations, non-ionic surfactants can perform an auxiliary antistatic function by increasing the electrical conductivity of particle surfaces through adsorption. Their use in this capacity is usually secondary to another, dominant function in the formulation.

Dispersants

Dispersants are excipients that facilitate and stabilise the uniform distribution of solids in a liquid (suspensions) or of one liquid in another (emulsions). Their action is based on controlling the zeta potential of the particles (electrostatic stabilisation) or forming an adsorption layer that prevents agglomeration (steric stabilisation).

Emollients

Emollients are excipients that soften and smooth the skin. They fill the spaces between the scales of the epidermis and form a protective film on the skin’s surface that reduces transepidermal water loss (TEWL). They are a key ingredient in creams, lotions, ointments and other dermocosmetics for skin care.

Rheology modifiers

Rheology modifiers are excipients that influence the flow properties of a formulation – its viscosity, thixotropy, yield point and behaviour under mechanical stress. Selecting the appropriate rheology modifier is crucial for achieving the desired consistency of the preparation (cream, gel, liquid, suspension) and controlling its behaviour during application.

Classification of excipients by chemical structure

The products in our range can also be categorised according to their chemical structure, which helps in understanding their properties and their interactions within formulations.

Polyethylene glycols (PEG)

Polyethylene glycols (PEG) are ethylene oxide polymers with the general formula H(_OCH₂CH₂)_nOH. They are linear, hydrophilic products with non-ionic properties.

Within the category of excipients, the PCC Group offers three particularly important classes of PEG:

• POLIkol 300EXC – PEG-6, liquid, low viscosity, excellent solubilisation and wetting properties;
• POLIkol 400EXC – PEG-8, liquid, moderate viscosity, widely accepted in pharmacopoeias;
• POLIkol 600EXC – PEG-12, liquid-semi-liquid, higher viscosity, effective rheology modifier and plasticiser.

PEG glycols belong to a group of popular excipients. Their safety profiles, physical and chemical properties, as well as quality testing methods, are described in detail in the Ph. Eur. (European Pharmacopoeia), USP/NF (United States Pharmacopeia) and other major pharmacopoeias.

Fatty alcohol ethoxylates

Fatty alcohol ethoxylates are formed by the condensation of fatty alcohols with ethylene oxide. These products combine lipophilic (derived from the fatty alcohol) and hydrophilic (PEG chain) properties, which gives them surfactant properties – they reduce surface tension and interfacial tension.

PCC’s offering in this product group includes ROKAnol T6EXC (Ceteareth-6) – an oxyethylene product derived from a mixture of cetyl and stearyl alcohols. The low degree of ethoxylation results in moderate hydrophilicity and an HLB value close to 9–10, making this product an effective O/W emulsifier in creams and emulsions.

Alkoxylated fatty acids (oxyethylated vegetable oils)

Oxyethylated vegetable oils – in particular oxyethylated castor oils – are products of the addition of ethylene oxide to natural castor oil. The result is a hydrophobic triglyceride core surrounded by hydrophilic PEG chains. These products exhibit outstanding solubilising and emulsifying properties.

ROKAcet R35EXC (PEG-35 Castor Oil) is a key representative of this group in PCC’s product range. Thanks to its triglyceride structure with PEG chains, this product forms effective micelles capable of solubilising large quantities of lipophilic substances in aqueous environments.

Sorbitan esters and polyoxyethylated sorbitan esters (polysorbates)

Sorbitan esters are products of the esterification of sorbitol with fatty acids. They are characterised by a low HLB value and act as W/O emulsifiers. Their polyoxyethylated derivatives – polysorbates – are more hydrophilic and are among the most important O/W emulsifiers and solubisers in the pharmaceutical industry.

ROKwinol 20EXC (Polysorbate 20) is a sorbitan laurate (C12 acid) ester with 20 EO units. This product is characterised by a high HLB value, excellent biodegradability and regulatory acceptance. Polysorbate 20 is widely used not only in oral, topical and parenteral formulations, but also in modern biopharmaceuticals as a stabiliser for therapeutic proteins.

Excipients in various pharmaceutical forms and cosmetic applications

Knowledge of the functions of excipients is essential, but it is equally important to understand in which specific drug and cosmetic formulations they are used. Below we present the key areas of application.

Excipients in tablets

Tablets remain the most widely used pharmaceutical form in the world. The manufacture of tablets with the appropriate hardness, disintegration rate, uniformity and release profile requires carefully selected excipients. In conventional coated tablets, PCC products act, amongst other things, as film coating plasticisers, solubilisers in the tablet core, or wetting agents added to the granules or coating in low concentrations.

Excipients in capsules

In hard and soft capsules, excipients ensure the appropriate filling properties: flowability, viscosity and solubilisation of the active ingredients. Polyethylene glycols from PCC’s range – e.g. POLIkol 400EXC – are a  classic component of liquid fillings for soft gelatin capsules (softgels), where they ensure the homogeneity and stability of the formulation.

Excipients in oral solutions and syrups

In liquid formulations (syrups, oral solutions, suspensions), the following are of key importance: good solubility of ingredients, chemical and microbiological stability, appropriate rheology and organoleptic acceptability. PEG glycols stabilise syrups and emulsions.

Excipients in dermocosmetics – creams, emulsions and gels

In cosmetic formulations, excipients from PCC’s range ensure emulsion stability, appropriate consistency, and the product’s skincare and sensory properties. Emulsifiers, humectants and emollients form the functional base for a wide range of skincare products: face and body creams, lotions, toners, essences, masks and emulsions.

Quality and regulatory requirements for pharmaceutical excipients

Pharmaceutical excipients are subject to stringent quality requirements, knowledge of which is essential for pharmaceutical formulators and the QA/QC departments of drug manufacturers.

Key standards and regulations include:

• European Pharmacopoeia (Ph. Eur.) – contains monographs for all excipients used in medicines intended for the European market; requirements cover purity, identity, physical properties and safety;
• USP/NF (United States Pharmacopeia / National Formulary) – analogous standards for the US market;
• IPEC (International Pharmaceutical Excipients Council) – an industry organisation publishing guidelines and standards for good manufacturing practice for excipients (GMP for Excipients);
• ICH Q8, Q9, Q10, Q11 – ICH guidelines on design, quality control and risk management in the development and manufacture of medicinal products
• Regulation (EC) No 726/2004 and Directive 2001/83/EC – the regulatory framework for medicinal products in the EU, including requirements for the declaration of excipients in registration dossiers.

Products in the Excipients category offered by the PCC Group as part of the EXC range are manufactured in accordance with pharmacopoeial requirements and are documented with full product specifications, certificates of analysis (CoA) and – upon customer request – IPEC documentation

Why choose the PCC Group’s excipients?

By choosing excipients from the PCC Group’s range, manufacturers of medicines, dietary supplements and cosmetics gain a number of significant benefits:

• Availability and flexibility of supply – As a major European manufacturer of chemical raw materials, the PCC Group guarantees regularity of supply and flexibility in terms of order volumes, which is crucial for supply chain management in the pharmaceutical industry. By working with a European manufacturer, you minimise the risk of supply chain disruptions or delays caused by the current geopolitical situation in other regions of the world.
• Samples – for most products, it is possible to order samples for testing purposes.
• Quality assurance and regulatory compliance – products from the EXC range are manufactured to rigorous standards and in accordance with the requirements of Ph. Eur. and IPEC GMP for Excipients. The necessary documentation will be made available to the customer on request.
• Batch reproducibility – a stable supply chain and a controlled manufacturing process ensure the reproducibility of key physicochemical parameters of the product, which is essential for maintaining the reproducibility of the drug formulation manufacturing process.
• Wide range of applications – PEG glycols, ethoxylated castor oils, alkoxylated fatty alcohols and polysorbates from PCC’s range fulfil multiple technological functions simultaneously, which simplifies formulation and reduces the number of raw materials in the formulation.

Excipients in medicines, cosmetics and dietary supplements are an integral part of every modern pharmaceutical and cosmetic product. Their appropriate selection and quality directly influence the efficacy, safety, stability and acceptability of the preparation by the patient or consumer.

The PCC Group’s range in the Excipients category includes, among others, carefully selected products – polyethylene glycols (POLIkol 300EXC, 400EXC, 600EXC), oxyethylated castor oil (ROKAcet R35EXC), ethoxylated cetearyl alcohol (ROKAnol T6EXC) and polysorbate 20 (ROKwinol 20EXC) – which together form a complete range of excipients for the formulation of a wide variety of pharmaceutical and cosmetic products.

Each product comes with quality documentation,  and its quality complies with pharmacopoeial and regulatory requirements, enabling their use in medicinal products subject to registration in the EU and other global markets.

If you are looking for proven, high-quality excipients for pharmaceutical, dermocosmetic or dietary supplement formulations, we invite you to review the detailed product data sheets and to contact the PCC Group’s technical and sales department.