title: [Magistral prepared lidocaine-gel for topical aplication on skin].
abstract: Due to a limited availability of industrially manufactured products containing local anesthetics for skin application and an increased demand for lidocaine-containing gel applicable prior to a product containing capsaicin for neuropathic pain treatment, it is necessary to prepare a topical semi-solid preparation containing the local anesthetic in pharmacies. Our aim was to create a mixed system of a hydrophilic gel with the emulsified drug, using excipients to decrease the lidocaine melting point, thereby creating a eutectic mixture with a high concentration of lidocaine in the oil phase. Based on bibliographic data, thymol creating a binary eutectic system containing lidocaine has been chosen. After addition of other excipients, an emulsion system was prepared and the drug was stabilized in the oil phase by a mixed nonionic emulsifier and carbomera. For the optimal anesthetic effects, the pH value should be adjusted; trometamol has been chosen as a suitable basic reacting excipient. Based on the addition of different amounts of trometamol, pH values of individual emulgels have been measured and the final composition of lidocaine emulgel has been created. A recipe for a 5 % lidocaine emulgel with the pH value of 9.1 has been created, based on the gel-forming substance carbomera with an emulsion of the oil phase containing a eutectic mixture of lidocaine and thymol, with an addition of ethanol and propylenglycol, stabilized by a mixed nonionic emulsifier. The advantage is the absence of other local anesthetics.
authors.affiliation: Farmakologický ustav 1. lékarské fakulty UK, Albertov 4, 128 00 Praha 2, Ceská republika. zbynek.sklenar@gmail.com
authors.forename: Zbynĕk
authors.initials: Z
authors.lastname: Sklenár
authors.forename: Katerína
authors.initials: K
authors.lastname: Horácková
authors.forename: Hana
authors.initials: H
authors.lastname: Bakhouche
authors.forename: Ondrej
authors.initials: O
authors.lastname: Slanar
mesh_terms: D000279:Administration, Cutaneous; D000779:Anesthetics, Local / Q000008:administration & dosage; D004339:Drug Compounding / Q000379:methods*; D005782:Gels; D008012:Lidocaine / Q000008:administration & dosage
chemical_list: D000779:Anesthetics, Local; D005782:Gels; D008012:Lidocaine