1. Field of the Invention
The present invention relates to pharmaceutical preparations for external use. More specifically, it relates to preparations which are prepared by dissolving a non-steroid antiphlogistic analgesic agent in peppermint oil and/or a salicyclic acid ester and making the solution into a pharmaceutical form using a base for external use.
2. Description of the Prior Art
A great number of kinds are known as non-steroid antiphlogistic analgesic agents. Representative examples among those are ibuprofen, indomethacin, ketoprofen, flurbiprofen, suprofen, etc. The conventional pharmaceutical forms of these are orally administrable preparations and suppositories, and it is believed that any suitable form as a preparation for external use has not yet been known. Only one exception is a recent proposal on indomethacin being presented as an ointment comprising a mixture thereof with a glycol, a lower alcohol and water along with a gelling agent (see Japanese Patent Application Laid-open No. 81616/1978).
On the other hand, the non-steroid antiphlogistic analgesic agents, although being excellent in antiphlogistic or analgesic effect, sometimes exhibit drastic side effects upon the digestive organs in the case of the oral administration or on the rectum in the case of the suppository, and therefore, many investigations have been made in order to eliminate such a problem, but this has not been solved to this day.
The present inventor has discovered as the result of the intensive study that compounds which are non-steroid antiphlogistic analgesic agents and have an acetic acid or propionic acid group in the molecule are suprisingly capable of being readily soluble in such adjuvants as peppermint oil, salicyclic acid esters which exhibit pharmaceutical efficacy as such and that preparations for external use prepared using such solutions are extremely excellent as antiphlogistic or analgesic agents, thereby having accomplished the present invention.
The peppermint oil used in this invention has topical vasodilating effect, anticonvulsive effect, and used for external use in the form of an aqueous solution, poultice, plaster or the like or used as a topical stimulant for gargling (see Oleum Menthae Japonicae, Japanese Pharmacopeia and Peppermint, British Pharmacopeia). However, no example has been presented in which the peppermint oil is used as a solvent for antiphlogistic analgesic agents. Also, as for the salicylic acid esters used in this invention, there has been known no example where such are used as a solvent for antiphlogistic analgesic agents.