G.R. No. L-23954. April 29, 1977.
AMERICAN CYANAMID COMPANY, petitioner, vs. THE DIRECTOR OF PATENTS and TIU CHIAN, respondents.

FACTS

Petitioner American Cyanamid Company sought the cancellation of Certificate of Registration No. 5348 for the trademark “SULMETINE,” issued to respondent Tiu Chian for a veterinary medicine used to treat diseases in chickens and domesticated birds. Cyanamid claimed prior ownership and use of the trademark “SULMET” for its similar veterinary product, first used in the Philippines in 1950 and for which it filed a registration application in 1956. It argued that through extensive use and promotion, “SULMET” had acquired widespread reputation and that Tiu Chian’s “SULMETINE” was confusingly similar, constituting unfair competition.
Respondent Tiu Chian opposed the petition. The Director of Patents denied the cancellation, finding no confusing similarity. The decision highlighted differences: Cyanamid’s “SULMET” product was a drinking water solution for a broader range of animals, while Tiu Chian’s “SULMETINE” was in tablet form specifically for birds. The labels were distinct, with Cyanamid’s prominently displaying “CYANAMID” and its company name, and Tiu Chian’s featuring “HENRY’S” and rooster imagery. The Director also noted that “SUL” and “MET” were derived from common chemical terms (“sulfa” and “methyl”), and the addition of “INE” created a marked distinction.

ISSUE

Whether the Director of Patents erred in ruling that the trademark “SULMETINE” is not confusingly similar to “SULMET” and in denying the petition for cancellation.

RULING

The Supreme Court affirmed the decision of the Director of Patents. The legal logic centered on the test for confusing similarity, which requires an examination of the trademarks in their entirety, considering the sound, appearance, and meaning, as well as the nature of the goods and the context of their sale. The Court upheld the Director’s factual findings that the differences between the marks and their associated labels were substantial and striking enough to prevent consumer confusion. The prominence of different house marks (“CYANAMID” vs. “HENRY’S”), the distinct product forms (solution vs. tablets), and the specific animal indications on the labels were deemed sufficient to distinguish the products in the market.
The Court further agreed that the syllables “SUL” and “MET” were descriptive, derived from common chemical nomenclature, and thus not subject to exclusive appropriation by the petitioner. The addition of “INE” created a distinct composite mark. The absence of proof of actual damage to Cyanamid’s sales—which in fact increased during the period—buttressed the conclusion that no confusion existed. The Court also rejected procedural challenges to the hearing officer’s authority, finding any objection waived due to the petitioner’s full participation in the proceedings. The decision underscores the principle that in trademark disputes, the determination of confusing similarity is a factual matter where the findings of the Patent Office, supported by substantial evidence, are accorded great weight.