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Allergic Contact Dermatitis to Ingredients other than the Active Drug
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
In cases of allergic contact dermatitis from topical pharmaceuticals, the allergenic culprit may be either the active drug or one or more of the other components, for example vehicle ingredients, preservatives, antioxidants, fragrances or other chemicals present in the topical drug product. Such reactions to non-drug components are far from rare. In eye drops, for example, many allergic reactions have been reported to the preservatives thimerosal and benzalkonium chloride. In creams and ointments, especially those used for herpes simplex (acyclovir), fungal infections (ketoconazole), and in topical corticosteroids, propylene glycol was often found to be the allergenic culprit. It should be realized, though, that these chemicals tend to cause irritant patch test reactions, and there can be no doubt that a number of the ‘allergic’ reactions reported have, in fact, been false-positive.
Preservative Resistance
Published in Philip A. Geis, Cosmetic Microbiology, 2020
If a microorganism is resistant to the antimicrobial activity of a chemical disinfectant, it is possible that it is also resistant to a preservative in a product formulation if the active ingredient is in both the disinfectant and preservative. For example, a strain of Pseudomonas aeruginosa has been found to be resistant to N-dodecylpyridinium iodide (P-12), whose structure is similar to that of a common disinfectant, cetylpyridinium chloride (71). Pseudomonas aeruginosa has been well known to survive and proliferate in solutions of benzalkonium chloride (72). Benzalkonium chloride and cetylpyridinium chloride are QACs. It is well known that Gram-negative bacteria are less susceptible to QACs than Gram-positive bacteria, and Pseudomonas spp. have generally high intrinsic resistance compared to other Gram-negative bacteria (44). In addition, Pseudomonas spp. may adapt to survive against higher concentrations of QACs (73). In addition to being active ingredients in disinfectants, benzalkonium chloride and cetylpyridinium chloride can be used as preservatives in product formulations. If a microbial isolate in the manufacturing equipment is resistant to the antimicrobial activity of a benzalkonium chloride or cetylpyridinium chloride disinfectant, they could contaminate a finished product. If a finished product contains either benzalkonium chloride or cetylpyridinium chloride as the preservative, the resistant isolate may survive and eventually proliferate in that formulation.
Leg ulcers: diagnostic approach and management
Published in Robert A. Norman, Geriatric Dermatology, 2020
A. I. Rojas, Y. M. Bello, T.J. Phillips
Topical antiseptic agents are cytotoxic in vitro and potentially sensitizing39,40. The use of hexachlorophene, benzalkonium chloride, chlorhexidine, gentian violet and alcohol should be discouraged on open wounds. Hydrogen peroxide has a transient antimicrobial activity and although toxic for fibroblasts in vitro did not impair wound healing in vivo37,41. Ethanoic (acetic) acid is very useful for the treatment of ulcers colonized with Pseudomonas aeruginosa. However, in concentrations of 0.25% it impairs wound healing when compared with normal saline treated wounds41. Cadexomer iodine is an antiseptic that releases iodine at low concentrations which do not appear to be toxic in vivo42–44. Cadexomer iodine appears to be a safe alternative to hydrocolloids and paraffin gauze dressings in the treatment of venous leg ulcers, especially for highly exudative wounds45,46.
Lacrimal Gland Insufficiency in Aqueous Deficiency Dry Eye Disease: Recent Advances in Pathogenesis, Diagnosis, and Treatment
Published in Seminars in Ophthalmology, 2022
These have been the first line of management in patients with ADDE, regardless of the disease severity. They are known to improve the ocular surface lubrication, tear retention, tear osmolarity and TBUT and reduce the ocular surface staining. However, there are various types of artificial tears available which differ in its constituents.73,74 Preservatives such as benzalkonium chloride should be avoided as it causes stinging sensation and ocular surface toxicity with long-term use. The pH of the human tear is between 6.9 and 7.5. Any compound having a higher pH causes burning sensation upon instillation. These factors further worsen the pre-existing symptoms of a patient with DED. Current recommendations are that a preservative-free compound having a lower pH should be preferred. Due to the varied compositions, the drops need to be individualized in every patient.
Lactic acid, citric acid, and potassium bitartrate non-hormonal prescription vaginal pH modulator (VPM) gel for the prevention of pregnancy
Published in Expert Review of Clinical Pharmacology, 2022
Benzalkonium chloride is both a spermicide and bactericidal agent that has been in use since 1935, however it is not approved by the U.S. FDA for contraception [27]. In concentrations above 0.007% it has the ability to immobilize sperm [27]. Clinical studies assessing the efficacy of benzalkonium chloride as a contraceptive have resulted in 17 pregnancies in 1998 cases (Pearl Index 1.1) [27]. A further multicenter phase III trial assessing contraceptive efficacy, tolerance and acceptability showed out of 653 women who were using the product, 23 became pregnant (Pearl Index 1.4) [27]. Benzalkonium chloride is generally well tolerated with one or more side effects reported in 22.6% of women – resulting in a discontinuation rate of only 2.4% [27]. A recent phase IV study involving 151 women age 40 and above in France and Russia was completed but has not released results [28]. However, as benzalkonium chloride immobilizes sperm by rupturing the integrity of the plasma membrane, similar to other spermicides, its safety has been debated, with a rising amount of evidence suggesting these products can increase susceptibility to STIs [29]. This occurs due to the harmful effects spermicides can have on the lining of vaginal epithelium triggering inflammatory responses as well as disrupting the balance of vaginal microbiota [29].
Relieving the symptoms of dry eye disease: update on lubricating eye drops containing hydroxypropyl-guar
Published in Clinical and Experimental Optometry, 2021
Renee Garofalo, Carolina Kunnen, Rekha Rangarajan, Venkiteshwar Manoj, Howard Ketelson
In addition to HPG, the Systane family of lubricant eye drops share a unique antimicrobial polycationic preservative, polyquaternium-1 0.001% (POLYQUAD®, Alcon Laboratories, Inc., Fort Worth, TX, USA).24–26 Preservatives with antimicrobial activity are necessary to prevent accidental contamination of ophthalmic solutions packaged in multiuse containers. Polyquaternium-1 has been in use since the mid-1980s in contact lens solutions, artificial tears, and ocular hypotensive agents.26–31 It is more compatible with the ocular surface than the commonly used antimicrobial agent, benzalkonium chloride. Benzalkonium acts as a detergent, disrupting the cell walls of bacteria, but it can also disrupt the integrity of mammalian cells. Polyquaternium-1 causes blebbing and leakage of K+ from the cell walls of bacteria, but not mammalian cells. Both polyquaternium-1 and benzalkonium are effective antimicrobial agents, but polyquaternium-1 is less cytotoxic to the ocular surface than benzalkonium.19,32–36