PHARMACOLOGIC PROPERTIES OF TROPINE 4-CHLOROBENZHYDRYL ETHER HYDROCHLORIDE (SL-6057), A POTENT LONG-ACTING ANTIHISTAMINIC AGENT

¹ Departnment of Pharmacology, Marquette University School of Medicine, Milwaukee, Wisconsin

Tropine 4-chlorobenzhydryl ether hydrochloride, SL-6057 or FC-1 , shows potent and remarkably long-acting antihistaminic activity in laboratory animals. In guinea pigs, following single oral or intraperitoneal administration, SL-6057 affords better and much longer protection against fatal histamine sprays than Pyribenzamine, Chlor-Trimeton or Phenergan.

SL-6057 produces considerably longer local anesthetic effects than procaine, as determined by intradermal injection in guinea pigs and sciatic nerve block in rats. However, it produces local irritation upon intradermal infiltration in guinea pigs with 0.5 per cent solution and subcutaneous injection in rabbits with 2.0 per cent solution.

SL-6057 possesses moderate antispasmodic and anticholinergic activities both in vitro and in vivo in several species of animals, compared with atropine and Banthine.

SL-6057 has fewer mydriatic and antisalivary effects than atropine.

SL-6058, the methyl bromide of SL-6057, has similar but less pharmacologic activities than SL-6057.

The acute toxicity in mice, rats and dogs and chronic toxicity determinations in rats and dogs indicate that SL-6057 is relatively non-toxic.