PCA, also known as Pyrrolidone Carboxylic Acid, L-Pyroglutamic Acid, Pidolic Acid or 5-Oxoproline, is a functional cosmetic ingredient primarily used for its humectant and moisturising properties. The INCI name is PCA. The L-form is identified by CAS Number 98-79-3, EC Number 202-700-3, molecular formula C₅H₇NO₃, and molecular weight 129.11 g/mol.
PCA is a naturally occurring component associated with the skin's Natural Moisturising Factor (NMF). In cosmetic formulations, it is used to support moisture retention and help maintain a soft, conditioned skin feel. COSMILE Europe identifies PCA specifically for humectant and moisturising functions.
PCA is also chemically important as the parent acid from which several PCA salts are derived, including Sodium PCA, Potassium PCA, Magnesium PCA and Calcium PCA. These salts have related moisture-management functions but are chemically distinct ingredients.
PCA is the cyclic form of glutamic acid and is chemically described as L-2-Pyrrolidone-5-carboxylic acid. It is also known as 5-Oxo-L-proline and L-Pyroglutamic Acid. The molecule contains a five-membered lactam ring together with a carboxylic acid group.
The L-form has the molecular formula C₅H₇NO₃ and molecular weight 129.114 g/mol. CAS 98-79-3 corresponds to L-Pyroglutamic Acid, while 149-87-1 is associated with the DL form. This stereochemical distinction should be maintained in technical documentation and raw-material specifications.
PCA is a hygroscopic, water-compatible material. A technical reference for L-Pyroglutamic Acid reports a white to almost-white powder or crystalline material, water solubility and a melting range around 157–164°C. These values relate to a particular analytical grade and should not automatically be transferred to every commercial cosmetic grade.
PCA is primarily used as a humectant and moisturising cosmetic ingredient. Its water-binding characteristics allow it to contribute to moisture retention in cosmetic formulations and support a hydrated skin feel.
PCA is particularly relevant because it is naturally associated with the skin's NMF. This makes it useful in hydration-focused formulations where the objective is to support the skin's moisture environment.
PCA can also be formulated alongside other humectants such as glycerin, Betaine, Sodium PCA, Potassium PCA, Sorbitol and other water-compatible moisturising ingredients. The free-acid form can also influence the acidity of a formulation, so formulation pH should be evaluated during development.
PCA Cosmetic Ingredient can be used in a variety of skin-care, hair-care and personal-care formulations. Typical applications include moisturising creams, facial lotions, serums, gels, toners, body-care products, hand-care products and other hydration-focused preparations.
In skin-care formulations, PCA can provide a water-binding component in moisturising systems. It can be combined with emollients, occlusive ingredients, polymers and other humectants to develop formulations with different sensory and hydration characteristics.
PCA can also be considered in hair-care formulations where moisture management and conditioning are desired. The appropriate grade and concentration should be determined according to the formulation objective, finished-product characteristics and applicable market requirements.
PCA salts such as Sodium PCA and Potassium PCA can be selected separately when the formulation requires a salt form rather than the free PCA acid.
The acidic nature of PCA should be considered when incorporating it into a cosmetic formulation. Unlike neutral or salt-form PCA ingredients, the free acid can contribute to the overall pH of the formulation. The final pH should therefore be adjusted and evaluated according to the finished product.
PCA is hygroscopic, so moisture exposure during storage and handling should be controlled. A referenced analytical grade recommends storage in a cool, dark environment and identifies hygroscopicity as a condition requiring attention.
PCA and its salts have been reviewed by the Cosmetic Ingredient Review Expert Panel. The assessment concluded that PCA and its salts are safe under the practices and concentrations described in the assessment, with the specific precaution that PCA and its salts should not be used in cosmetic products where N-nitroso compounds can be formed.
For commercial procurement, the actual Certificate of Analysis should be used to establish assay, optical purity, moisture, residue, heavy metals, pH and impurity limits. Public references do not establish one universal cosmetic raw-material COA for every PCA grade.
As a PCA Cosmetic Ingredient Manufacturer in India, Swapnroop focuses on supplying cosmetic raw materials for skin-care, hair-care and personal-care formulation requirements.
PCA is suitable for manufacturers developing moisture-management and hydration-focused products. For bulk procurement, the selected grade should be evaluated according to its stereochemical identity, purity, moisture, physical characteristics and applicable impurity requirements.
Product documentation should clearly identify PCA / L-2-Pyrrolidone-5-carboxylic acid, CAS 98-79-3, to distinguish the free acid from Sodium PCA, Potassium PCA, Magnesium PCA and other PCA derivatives.
| Parameter | Specification |
|---|---|
| Appearance | White or colourless crystals / white powder |