pharmacal

The pen-name, O. Henry, is almost certainly borrowed from a French chemist, Etienne-Ossian Henry, whose abridged name he fell upon in his pharmacal researches.

O. Henry 1921

Once lost sight of, and trade competition substituted for competition in serving the interests of the sick, medical and pharmacal practice will become an ignoble scrabble for wealth, in which the sick become victims of avarice and greed.

Alcohol: A Dangerous and Unnecessary Medicine, How and Why What Medical Writers Say Martha Meir Allen 1890

It is not the object of these laws to create odious monopolies, to throw a mantle of protection over fraud, to enable quacks and charlatans to encroach on the domain of legitimate medical and pharmacal practice, or to support an advertising business designed to mislead the public in regard to the nature and value of medicines as curative agents.

Alcohol: A Dangerous and Unnecessary Medicine, How and Why What Medical Writers Say Martha Meir Allen 1890