Hexadecylphosphocholine (He-PC) is a new compound synthesized according to the minimal structural requirements deducted from studies with other ether lipids. In vitro studies on He-PC revealed remarkable antineoplastic activity on HL60, U937, Raji and K562 leukemia cell lines. In addition, He-PC, applied orally, showed a superior effect in the treatment of dimethylbenzanthracene-induced rat mammary carcinomas when compared to intravenously administered cyclophosphamide. After oral application He-PC was well absorbed from the intestine and metabolized in the liver by phospholipases C and D. During a 5-week treatment no hematotoxic effects were detected. In a clinical pilot study on breast cancer patients with widespread skin involvement, topically applied He-PC showed skin tumor regressions without local or systemic side effects.

Distribution and metabolic fate of radiolabeled hexadecylphosphocholine (He-PC) has been studied in mice. It is demonstrated that He-PC is well-absorbed from the intestinal tract, intravenous (IV) and oral administration lead to similar distributions throughout the body, the highest accumulation of radioactivity occurs in liver, lung and kidney, and the metabolic products are radioactive choline, phosphocholine and 1,2-diacylphosphatidylcholine. The occurrence of these metabolites indicates that phospholipases C and D may be involved in He-PC breakdown.

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Involuntary lid closure not rarely accompanies aberrant regeneration of nerve fibers after different types of facial paralysis. 23 patients with such synkinesis were treated with botulinum toxin injections into the orbicularis oculi muscle. After periocular injections all patients showed much improvement: a period of, on the average, 13 symptom-free weeks was followed by a period of minimal symptoms. There were only minor complications. Whenever repeated treatment is necessary, botulinum toxin proves to be an effective therapy for involuntary lid closure after defective healing following facial paralysis.