chemistry

Polyhexanide

Polyhexanide is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Polyhexanide rather than just read about it. In short: Polyhexanide (polyhexamethylene biguanide, PHMB) is a polymer used as a disinfectant and antiseptic. In dermatological use, it is spelled polihexanide (INN) and sold under various brand names.

Key takeaways

Polyhexanide belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Polyhexanide to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Polyhexanide from memory before moving on to harder problems.

Reference excerpt

Polyhexanide (polyhexamethylene biguanide, PHMB) is a polymer used as a disinfectant and antiseptic. In dermatological use, it is spelled polihexanide (INN) and sold under various brand names. PHMB has been shown to be effective against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans, Aspergillus brasiliensis, enterococci, and Klebsiella pneumoniae. Polihexanide, sold under the brand name Akantior is a medication used for the treatment of Acanthamoeba keratitis. Products containing PHMB are used for inter-operative irrigation, pre- and post-surgery skin and mucous membrane disinfection, post-operative dressings, surgical and non-surgical wound dressings, surgical bath/hydrotherapy, chronic wounds like diabetic foot ulcer and burn wound management, routine antisepsis during minor incisions, catheterization, first aid, surface disinfection, and linen disinfection. PHMB eye drops have been used as a treatment for eyes affected by Acanthamoeba keratitis. Ready-to-use preparations for direct application in or on the human body in clinical use: Lavanid, Lavasept, Prontoderm, Prontomed, Prontosan, Serasept, Suprasorb X+PHMB und Suprasorb P+PHMB

It is sold as a swimming pool and spa disinfectant in place of chlorine or bromine based products under the name Baquacil. PHMB is also used as an ingredient in some contact lens cleaning products, cosmetics, personal deodorants and some veterinary products. It is also used to treat clothing (Purista), purportedly to prevent the development of unpleasant odors. The PHMB hydrochloride salt (solution) is used in the majority of formulations.

Use in Acanthamoeba keratitis treatment Polihexanide is indicated for the treatment of Acanthamoeba keratitis in people aged 12 years of age and older.

Legal status In May 2024, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Akantior, intended for the treatment of Acanthamoeba keratitis, a severe, progressive and sight threatening corneal infection characterized by intense pain and photophobia. Acanthamoeba keratitis is a rare disease primarily affecting contact lens wearers. The applicant for this medicinal product is SIFI SPA. Polihexanide was approved for medical use in the European Union in August 2024.

Safety In 2011, polyhexamethylene biguanide was classified as category 2 carcinogen by the European Chemical Agency, but it is still allowed in cosmetics in small quantities if exposure by inhalation is impossible.

Name controversy In some sources, particularly when listed as a cosmetics ingredient (INCI), the polymer is wrongly named as polyaminopropyl biguanide.

References

Illustrations

Worked examples

Example 1 — a first encounter with Polyhexanide

Start with the simplest possible case. Write down what Polyhexanide claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Polyhexanide before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Polyhexanide ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Polyhexanide

In research: Polyhexanide appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Polyhexanide in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Polyhexanide is common in secondary-school and first-year university syllabi. It links to neighbouring topics Antiseptics and disinfectants, Biguanides, Polymers, so understanding it makes those chapters shorter.
In everyday life: Look for Polyhexanide outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Polyhexanide in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Polyhexanide means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Polyhexanide out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Polyhexanide in simple terms?

Polyhexanide (polyhexamethylene biguanide, PHMB) is a polymer used as a disinfectant and antiseptic. In dermatological use, it is spelled polihexanide (INN) and sold under various brand names.

Why does Polyhexanide matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Polyhexanide?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Polyhexanide.