Pharmacokinetics of benzydamine after intravenous, oral, and topical doses to human subjects

Abstract

The pharmacokinetics of the anti-inflammatory drug benzydamine were determined after intravenous infusion of 5 mg to six healthy male subjects. Benzydamine was characterized as a drug of relatively low systemic clearance (ca. 160 ml min-1) but high volume of distribution (ca. 1101); the apparent terminal half-life in plasma was ca. 8 h. Benzydamine was well absorbed after oral administration, as indicated by a mean systemic availability of 87 per cent. However, absorption of the drug was low (less than 10 per cent of the dose) after its use by male subjects as a mouthwash, or after its application to female subjects as dermal cream and vaginal douche preparations. The data suggest that benzydamine is generally not well absorbed through the skin and non-specialized mucosae, thereby limiting unrequired systemic exposure to this drug when it is used by these routes.

Effect of prophylactic benzydamine hydrochloride on postoperative sore throat and hoarseness after tracheal intubation using a double-lumen endobronchial tube: a randomized controlled trial

“…Benzydamine hydrochloride is absorbed rapidly and completely following systemic administration, whereas topical application results in slower, less complete absorption. 16 Thus, BH concentrations remain high in local tissue following topical application of the drug and may exert a therapeutic effect at the target site, limiting unnecessary systemic exposure. Topical administration of BH as an oral rinse has been shown to be an effective and safe treatment for pharyngitis 17,18 and radiation-induced oral mucositis in patients with head and neck tumours.…”

Pharmacokinetics of benzydamine in dairy cows following intravenous or intramuscular administration

“…However, to calculate a dosage regimen we can only ~refer to the serum concentrations found in humans, which are higher than 200 ng/ml at-about 8 h after oral administration of 50 mg (Baldock et al, 1991). According to the general equation C = Vd(area ) "r/(FD x 1.44t~), where C is the assumed efficacious concentration in humans (200 ng/ml), D is the 1.2 mg/kg dose, F is the bioavailability set at 92.07%, and Vd(area ) and t~¢ were set at 3.5 L/kg and 297 rain, respectively, we calculate a dose interval'(r) of 11 h. Consequently, two daily administrations of benzydamine will assure therapeutic levels.…”

Pharmacology of benzydamine

“…When administered as a mouthwash, the recommended dose of benzydamine is 15 ml of a 4-mmol/L solution of the hydrochloride salt in water [4]. This high concentration is transient as the benzydamine solution is only used to rinse the mouth and the remaining material is diluted by saliva.…”

“…Benzydamine is fluorescent (excitation 306 nm; emission 362 nm) [3] and is detected fluorometrically in HPLC assays [4]. This absorbance and fluorescence in the ultraviolet region may be associated with a possible pharmacological effect.…”