Investigation of Acute Toxicity of Tilorone Ointment for Topical Treatment of Herpes Virus Infection

Introduction. Tilorone (amixin, dihydrochloride 2,7-bis[2-(diethylamino)ethoxy] fluorenone-9) is a low molecular interferon inducer that is effective against a wide range of viral infections including herpes viruses. The mechanism of tilorone antiviral action is associated with inhibition of virus-specific peptides translation in infected cells resulting in the suppression of virus replication. An appropriate therapy of the viral infections with external rash besides the systemic preparations must include topical drugs that will reduce clinical signs of infection, improve skin epithelialization, and decrease time of virus elimination. Considering this, we developed a new topical antiviral 2% tilorone preparation in the form of ointment.

The aim of investigation was to study the parameters of acute toxicity of the 2 % tilorone ointment.

Results and Discussion. In accordance with the requirements of the European Pharmacopoeia 8.0 the acute toxicity of the developed ointment was studied using two methods – intragastric administration and cutaneous application. All animals were treated in compliance with the European Convention for the Protection of Vertebrate Animals used for Experimental and Other Scientific Purposes [Council of Europe, Strasbourg, 2006].

Acute intragastric toxicity was carried out in two species of rodents [54 white outbred mice (20-25 g) and 27 white Vistar rats (200-220 g)] that were given intragastrically an aqueous solution of ointment at a dose of 0,5g/kg. Acute dermal toxicity was studied in 27 white outbred mice (20-25 g); the application area was 5,5-6,0 cm².

The animals were monitored daily for clinical signs (breathing, physical activity, convulsions, analgesia, muscle tone, ophthalmic, cardiovascular and gastrointestinal symptoms, diuresis, skin signs) in the course of 14 days. All the animals remained alive and active; the distinctive symptoms of intoxication were absent. It was also determined that an effective dose of 2% test ointment does not cause toxic effects on human body is DL₀≤0,4 g/kg.