Phenylephrine hydrochloride is a synthetic sympathomimetic chemical compound structurally similar to epinephrine and is produced using an asymmetric Sharpless dihydroxylation of 3-hydroxybenzaldehyde

Phenylephrine is an amine, an organic derivative of ammonia, belonging to the phenylethanamine class, a selective alpha-1 adrenoreceptor agonist with strong vasoconstrictive properties. 

What it is used for and where

Medical

Phenylephrine hydrochloride is a mydriatic agent that acts with selective stimulation on the alpha-1 receptor and is used to dilate the iris through stimulation of the iris dilator muscle. It is also used as a spray or oral medication for nasal decongestion.

During spinal and inhalation anaesthesia, it is used to treat vascular insufficiency by maintaining an adequate blood pressure level (1), to prolong spinal anaesthesia and as a vasoconstrictor in regional analgesia.

Cosmetics

It is a restricted ingredient as II/21 a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009

Safety

This study reports a case of phenylephrine hydrochloride-induced periorbital contact dermatitis with keratoconjunctivitis (2) and other studies confirm cases of allergic contact reactions from phenylephrine hydrochloride (3), which is considered to be one of the most common confirmed ophthalmic allergens (4) and an ophthalmic allergen (5). It would therefore be advisable to perform a patch test before putting phenylephrine hydrochloride drops in the eyes to ensure that no allergic problems arise. It should be noted, however, that some conjunctivitis may turn out not to be allergic, but caused by bacteria, usually if yellow serum emission is present and the eyelids stick together. Always, of course, ask the treating physician.

Su questo ingrediente sono stati selezionati gli studi più rilevanti con una sintesi dei contenuti:

"Phenylephrine hydrochloride studies"

• Molecular Formula C₉H₁₄ClNO₂
• Molecular Weight   203.66
• CAS  61-76-7
• UNII    04JA59TNSJ
• EC Number    200-517-3 
• IUPAC  Phenylephrine hydrochloride 

References_____________________________________________________________________

(1) Rajaei, H., Hezave, A.Z., Lashkarbolooki, M. and Esmaeilzadeh, F., 2013. Representing experimental solubility of phenylephrine hydrochloride in supercritical carbon dioxide and modeling solute solubility using semi-empirical correlations. The Journal of Supercritical Fluids, 75, pp.181-186.

(2) Kato M, Nitta K, Kano Y, Yamada M, Ishii N, Hashimoto T, Ohyama M. Case of phenylephrine hydrochloride-induced periorbital contact dermatitis with fulminant keratoconjunctivitis causing pseudomembrane formation. J Dermatol. 2018 Feb;45(2):e27-e28. doi: 10.1111/1346-8138.14077. 

(3) Moreno-Ancillo A, Munoz-Robles ML, Cabañas R, Barranco P, Lopez-Serrano MC. Allergic contact reactions due to phenylephrine hydrochloride in eyedrops. Ann Allergy Asthma Immunol. 1997 Jun;78(6):569-72. doi: 10.1016/s1081-1206(10)63217-6. 

(4) Temesvári E, Pónyai G, Németh I, Hidvégi B, Sas A, Kárpáti S. Periocular dermatitis: a report of 401 patients. J Eur Acad Dermatol Venereol. 2009 Feb;23(2):124-8. doi: 10.1111/j.1468-3083.2008.02949.x. 

(5) Herbst RA, Uter W, Pirker C, Geier J, Frosch PJ. Allergic and non-allergic periorbital dermatitis: patch test results of the Information Network of the Departments of Dermatology during a 5-year period. Contact Dermatitis. 2004 Jul;51(1):13-9. doi: 10.1111/j.0105-1873.2004.00334.x. 

Abstract. Periorbital dermatitis is common and can be due to the external use of ophthalmic drugs. We evaluated patch test results of the Information Network of the Departments of Dermatology. During a 5-year period (1995-99), of a total 49,256 patch-tested patients, 1053 (2.1%) were eventually diagnosed as allergic periorbital contact dermatitis (APD) and 588 (1.2%) as non-allergic periorbital dermatitis (NAPD). Patient characteristics between APD, NAPD and other cases (OCs) differed with respect to sex (19.7% male in both periorbital groups versus 36.3% in OCs), atopic dermatitis (10.4% in APD versus 60.2% in NAPD versus 16.9% in OCs) and age, APD being substantially more often (68.2%) aged 40 and above than NAPD (52.6%). Several of the top allergens in OCs [such as fragrance mix, Myroxylon pereirae resin (balsam of Peru), lanolin alcohol and potassium dichromate] caused significantly fewer positive test reactions in both periorbital groups. In contrast, thimerosal, phenylmercuric acetate, sodium disulfite, gentamicin sulfate, phenylephrine hydrochloride and benzalkonium chloride tested positively significantly more often in APD but not in NAPD, verifying them as true ophthalmic allergens. Finally, in 42 cases (4%) of APD patients, additional allergens were identified by testing of the patients' own substances (mostly beta-blockers, oxybuprocaine and dexpanthenol), supporting the necessity of testing with ophthalmic drugs as is where individual substances are not readily available.