Oxybuprocaine (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...

), also known as benoxinate or BNX, is an ester-type

local anesthetic A local anesthetic (LA) is a medication that causes absence of pain sensation. In the context of surgery, a local anesthetic creates an absence of pain in a specific location of the body without a loss of consciousness, as opposed to a general an ...

, which is used especially in

ophthalmology Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medic ...

and

otolaryngology Otorhinolaryngology ( , abbreviated ORL and also known as otolaryngology, otolaryngology–head and neck surgery (ORL–H&N or OHNS), or ear, nose, and throat (ENT)) is a surgical subspeciality within medicine that deals with the surgical a ...

. Oxybuprocaine is sold by

Novartis Novartis AG is a Swiss-American multinational pharmaceutical corporation based in Basel, Switzerland and Cambridge, Massachusetts, United States (global research).name="novartis.com">https://www.novartis.com/research-development/research-loc ...

under the brand names Novesine or Novesin. Safety for use in pregnancy and lactation has not been established.

Uses

* In

in order to numb the surface of the

eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...

(the outermost layers of the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power ...

and

conjunctiva The conjunctiva is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium ...

) for the following purposes:Drugs.com
Minims Oxybuprocaine Hydrochloride 0.4%
/ref> ** in order to perform a contact/applanation tonometry, ** for small operations, ** in order to remove small foreign objects from the uppermost layer of the cornea or conjunctiva; * in

for numbing the

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...

s of the

nostrils A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...

and

pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struc ...

, for diagnostic purposes and small operations, * for numbing the mucous membranes of

bronchi A bronchus is a passage or airway in the lower respiratory tract that conducts air into the lungs. The first or primary bronchi pronounced (BRAN-KAI) to branch from the trachea at the carina are the right main bronchus and the left main bronchus. ...

, for example in

bronchoscopy Bronchoscopy is an endoscopic technique of visualizing the inside of the airways for diagnostic and therapeutic purposes. An instrument (bronchoscope) is inserted into the airways, usually through the nose or mouth, or occasionally through a trac ...

Pharmacokinetics

Anaesthesia starts with a latency of 30 to 50 seconds and lasts for about 10 to 30 minutes, depending on

perfusion Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion is measured as the rate at which blood is deliver ...

. The drug is metabolised by

esterase An esterase is a hydrolase enzyme that splits esters into an acid and an alcohol in a chemical reaction with water called hydrolysis. A wide range of different esterases exist that differ in their substrate specificity, their protein structure, ...

s in blood plasma and liver.

Adverse effects

When used excessively, oxybuprocaine like any other topical anesthetic used in the eye and on mucous membranes (like for example

tetracaine Tetracaine, also known as amethocaine, is an ester local anesthetic used to numb the eyes, nose, or throat. It may also be applied to the skin before starting an intravenous (injection) to decrease pain from the procedure. Typically it is applied ...

proxymetacaine Proxymetacaine (INN) or proparacaine (USAN) is a topical anesthetic drug of the aminoester group. Clinical pharmacology Proxymetacaine is a local anesthetic which on topical application penetrates sensory nerve endings in the corneal tissue. Mec ...

and proparacaine) can cause irritation,

hypersensitivity Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. They are usually referred to as an over-reaction of the immune s ...

anaphylaxis Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follow ...

, irreversible corneal damage and even complete destruction of the cornea. (Excessive use means several times a day during several days or even weeks.)

Interactions

Oxybuprocaine is incompatible with

silver Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...

and

mercury Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Merc ...

salts, as well as basic substances. It also reduces the antimicrobial action of

sulfonamide In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this group is unreactive. ...

Synthesis

The nitration of 3-hydroxybenzoic acid 9-06-9(0) gives 3-hydroxy-4-nitrobenzoic acid 19-14-7(1). Fischer esterification with ethanol gives ethyl 3-hydroxy-4-nitrobenzoate 17-01-1(2). The phenoxide ion was then prepared from potash (3). Alkylation with

1-bromobutane 1-Bromobutane is the organobromine compound with the formula CH3(CH2)3Br. It is a colorless liquid, although impure samples appear yellowish. It is insoluble in water, but soluble in organic solvents. It is a primarily used as a source of the buty ...

supplied ethyl 3-butoxy-4-nitrobenzoate
CID:13346201
(4). The product is crystallized from hydrochloric acid, and then halogenation with thionyl chloride gives 3-butoxy-4-nitrobenzoyl chloride 3442-21-9(5). Esterification with diethylaminoethanol 00-37-8(6) gives 2-(diethylamino)ethyl 3-butoxy-4-nitrobenzoate
CID:13346204
(7) Lastly, catalytic hydrogenation over Raney-Nickel completes the synthesis of Oxybuprocaine (8).

References