Quaternium-15, a preservative, is one of the most used substances and is added to several cosmetics and other industrial products. Quaternium-15 is a mixture of isomers, where the cis-form is the dominant form and where the trans-form is the minor component present as an impurity. Quaternium-15 can be found under a variety of names, most commonly those of the Dow Chemical Company: Dowicil 200 (cis isomer only), Dowicil 75 and Dowicil 100 (both a mix of cis and trans isomers). The isolated cis-compound is used primarily in cosmetic applications, with a maximum permitted concentration in the EU of 0.2%. DOWICIL 200 preservative (cis form) is used primarily as a preservative in a wide variety of personal-care and cosmetic products. It is designed to provide highly effective broad-spectrum antimicrobial activity, especially in water-based formulations. It is used in both leave-on and rinse-off application such as baby-care products, hair-care products, lotions, powders, and creams. The mixed product (cis- and trans-) is used in a wider range of formulations such as: emulsifiable metal-cutting fluids; latex and emulsion paints; liquid floor polishes and floor waxes; glues and adhesives. Recently, the cis-form has been classified as a CMR substance with the classification toxic to reproduction, category 3. This classification only concerns the cis-isomer:

Clove oil is a natural product, derived from the Eugenia caryophyllata tree. Clove oil is 85 to 95% eugenol. Isoeugenol and methyleugenol make up 5 to 15% of the remaining ingredients. Isoeugenol is manufactured from eugenol by a process of isomerization. Isoeugenol have been used in foods and eugenol has been used in animal feeds. Isoeugenol is used as a fish anesthetic. The mechanism of action of isoeugenol in fish has not been determined. It is hypothesised that its effects are mediated via receptors controlling cellular ion channels in a similar way to that described for local anaesthetics. Reports of adverse reactions involving the use of isoeugenol in humans are primarily confined to incidents of contact sensitization or allergy following dermal exposure.

Imidurea (Imidazolidinyl urea) is used as an antimicrobial agent and preservative in cosmetics and toiletries. It is very active against gram and gram- bacteria as a synergist in combination with parabens. Imidazolidinyl urea is more active against bacteria than fungi and is often combined with parabens to provide a broad spectrum preservative system. This preservative is one of the most widely used preservative systems in the world. The Food and Drug Administration (FDA) considers imidazolidinyl urea as one of the most common antimicrobial agents used in cosmetics. Due to its high water solubility, imidazolidinyl urea can be incorporated into almost all water-based cosmetics, toiletries, and cold mix formulations. It is present in a wide range of liquid and powder products such as baby lotion, skin cream, sunscreens, shampoos, eyeliners, blush, perfumes, deodorants, hair dyes, shaving cream, and face masks. Imidazolidinyl urea is permitted for use in personal care products in the European Union at a maximum concentration of 0.6%. In Japan, imidazolidinyl urea is allowed in rinse-off cosmetics such as shampoo, body wash, and facial cleanser at a maximum concentration of 0.3%. Imidurea is an ingredient of FDA-approved NIZORAL® (ketoconazole) 2% Shampoo, indicated for the treatment of tinea (pityriasis) versicolor caused by or presumed to be caused by Pityrosporum orbiculare (also known as Malassezia furfur or M. orbiculare).

Betadex is a nonreducing cyclic compound composed of seven alpha-(1-4) linked D-glucopyranosyl units. It is a pharmacologically inactive substance. Betadex is useful for stabilizing, solubilizing or delivering intermediate size molecules. Cyclodextrins are cyclic oligosaccharides that have been used to modulate the composition of cholesterol and other lipids in biological membranes and have also been used as pharmaceutical excipients in the formulation of hydrophobic drugs. More recently, 2-Hydroxypropyl-β-cyclodextrins (HPβCDs) have gained attention as a potential therapeutic intervention for Niemann-Pick Disease Type C1 (NPC1) disease. HPβCDs are complex mixtures of different species, and variations in production may lead to differences in composition. 2-Hydroxypropyl-β-cyclodextrin dose-dependent effects against dysfunctional intracellular cholesterol trafficking in NPC1 cells.

Propylparaben is a bacteriostatic and fungistatic agent used as a preservative in cosmetic products, food and drugs. As a food additive, it has the E number E216. To increase the activity and reduce its dose propylparaben is used in a mixture with other parabens and in combination with other types of preservatives. Propylparaben is a chemical allergen capable of producing immunologically mediated hypersensitivity reactions. Chemically it is an ester of p-hydroxybenzoic acid.

Chlorquinaldol is a halogenated hydroxyquinoline with properties similar to those of clioquinol. It is mainly applied topically in infected skin conditions and in vaginal infections. The product is applied for local treatment of cortico-sensitive dermatosis with moderately manifested superinfection, acute and subacute eczema, dermatitis, pyodermia, intertrigo, infected wounds, dermatomycosis, pemphigus in newborn. Chlorquinaldol is also used as antiseptic, fungistat, or deodorant. Chlorquinaldol is not commercially available in the U.S. but is used in other countries principally as an amebicide for nonspecific diarrheas and gynecologic infections. It is known most commonly under the proprietary name of Sterosan. Other trade names include Cynotherax, Gyno-Sterosan, Saprosan, Siogeno, Siosteran, Slosteran and Steroxin.

There is not much information about ammonium phenolate. It is known, that this a salt of phenol and it is toxic if swallowed and is toxic in contact with skin.

Eugenol is sometimes called clove oil because it is the active element in cloves. It causes the aromatic smell typical of cloves and because of this property is often found in perfumes. Eugenol’s properties make it a good local antiseptic and analgesic. It is used in dentist offices to make zinc-oxide eugenol paste for temporary fillings. Eugenol also demonstrates antifungal and antimicrobial activity, showing efficacy against Candida albicans biofilms, Listeria monocytogenes and Escherichia coli. Eugenol is further described to induce reactive oxygen species (ROS) production and to scavenge ROS, thus demonstrating prooxidant and antioxidant effects. Also, Eugenol is used as a pesticide.

Daprodustat (DUVROQ) is a small molecule inhibitor of hypoxia-inducible factor prolyl hydroxylase (PHD) developed by GlaxoSmithKline for the treatment of anaemia in patients with chronic kidney disease (CKD). Inhibition of PHD prevents degradation of hypoxia-inducible factor (HIF), leading to the production of erythropoietin and subsequent induction of erythropoiesis. In June, daprodustat received its first approval in Japan for the treatment of renal anaemia.

Omidenepag isopropyl, a prodrug, is hydrolyzed in the eye to the active form (Omidenepag) which functions as a selective, nonprostaglandin, prostanoid EP2 agonist, has been developed by Ube Industries and Santen Pharmaceutical as an ophthalmic solution (EYBELIS®) for the treatment of glaucoma and ocular hypertension. Omidenepag isopropyl increases the outfow of aqueous humor via both the uveoscleral outfow and the trabecular outfow pathways, resulting in potent and stable reduction in intraocular pressure (IOP). In September 2018, omidenepag isopropyl ophthalmic solution 0.002% was approved in Japan for the treatment of glaucoma and ocular hypertension. On September 22, 2022, the FDA approved Santen’s Omlonti (omidenepag isopropyl), for the reduction of elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension.