The makers of Tylenol are suing the makers of Anacin, charging, for the second time, that Anacin's television commercials are misleading consumers and saying they should be forced off the air.

American Home Products Co. is unjustified in claiming "Anacin also reduces inflammation while it relieves body pain," contends the lawsuit filed by McNeilab Inc. a subsidiary of Jonson & Johnson.

In the $650 million a year over-the-counter pain reliever business, McNeil's Tylenol is the biggest seller ad AHP's Anacin is the biggest advertiser.

Anacin spends $21 million a year on advertising, according to estimates of Advertising Age, the trade newspaper.

last August Tyleonol made advertising history by for the first time forcing a rival commercial off the air with a lawsuit.

A federal judge granted an injunction ordering Anacin to stop using commericals in which an announcer said, "your body knows the difference" between Anacin and Tylenol in relieving pain and inflammation.

The judge in New York ruled, "There is no reliable evidence showing (Anacin) reduces inflammation" but said there is no proof the dlaim is false either, saying, "the state of medical and scientific knowledge is not such to allow anyone to make a definitive conclusion either way.

His order banned Anacin advertising which claimed it is superior to Tylenol "gneraly or for conditions which are associated with inflammation."

The new Anacin commercials no longer mention Tylenol, but the latest lawsuit charges the advertising campaign "carries on with a minimum of disruption . . . essentially the same false and misleading anti-inflammatory claims."

The lawsuit, filed in U.S. District Court in New York, again asks an injunction stopping the commercials. Officials of McNeil and American Home Products refused to respond to inquiries about the dispute.

SInce Tylenol last year became the number one seller in the internal analgesics market, rival products have stressed in their advertising that Tylenol lacks the anti-inflammatory effects of aspirin.

Anacin contains aspirin plus caffeine. The active ingredient in Tylenol is acetaminophen, a non-aspirin pain reliever also known as APAP.

Aspirin and Anacin are not useful in relieving inflammation when taken in the usual quantities, the original decision said, although they are frequently recommended for that purpose in much higher doses.