[Base in four types of lidocaine preparation (formulated in hospital)].
PL cream (combination of lidocaine and procaine) was launched on the market in April 2012 in Japan. We investigated differences in the anesthetic effect by employing two types of base: Carbopol and methylcellulose. Electron microscopy showed a distinct difference in appearance: densely-scattered, fine particles for Carbopol and sparse, large particles for methylcellulose. Accordingly, the extensibility of the cream was significantly greater at 4 and 25 degrees centigrade for methylcellulose, but was greater at 34 degrees centigrade for Carbopol. The steady flow viscosity (1 s(-1)) was greater for the Carbopol than methylcellulose base. The difference in the cutaneous permeability between the two bases increased over time: the methylcellulose base was removed at 90 min after application and, 30 min later, showed a significant difference. These results suggest that the methylcellulose base has a superior anesthetic effect in clinical settings.
Department of Plastic, Oral and Maxillofacial Surgery, Teikyo University School of Medicine.
Hisayo
H
Yamaoka
Moemi
M
Saito
Keiji
K
Maruyama
Tamaki
T
Watanabe
Kazuo
K
Maruyama
Ryo
R
Suzuki
Shigekazu
S
Watanabe
Masatoshi
M
Tsuchiya
Yoshitaka
Y
Uchida
Masato
M
Mochizuki
Tomoyo
T
Yamanobe
Keiko
K
Yamaoka
Shinichi
S
Hirabayashi
D000180:Acrylic Resins / Q000737:chemistry; D000287:Administration, Topical; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002626:Chemistry, Pharmaceutical; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008012:Lidocaine / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008747:Methylcellulose / Q000737:chemistry; D051379:Mice; D008819:Mice, Nude; D009823:Ointment Bases; D010146:Pain / Q000517:prevention & control; D010539:Permeability; D012867:Skin / Q000378:metabolism; D014783:Viscosity
D000180:Acrylic Resins; D000779:Anesthetics, Local; D009823:Ointment Bases; C006912:carboxypolymethylene; D008747:Methylcellulose; D008012:Lidocaine