Smith Kline Beckman Corporation vs. Court of Appeals

G.R. No. 126627. August 14, 2003.*

When the language of its claims is clear and distinct, the patentee is bound thereby and may not claim anything beyond them.


In 1986, Smith Kline Beckman Corporation,  a foreign corporation licensed to do business in the Philippines filed before the Philippine Patent Office an application for patent over an invention entitled “Methods and Compositions for Producing Biphasic Parasiticide Activity Using Methyl 5 Propylthio-2-Benzimidazole Carbamate.” The application bore Serial No. 18989. In 1981,  Letters Patent No. 145611 for the aforesaid invention was issued to petitioner for a term of seventeen (17) years. The letters patent provides in its claims that the patented invention consisted of a new compound named methyl 5 propylthio-2-benzimidazole carbamate and the methods or compositions utilizing the compound as an active ingredient in fighting infections caused by gastrointestinal parasites and lungworms in animals such as swine, sheep, cattle, goats, horses, and even pet animals.

Tryco Pharma Corporation (private respondent) is a domestic corporation that manufactures, distributes and sells veterinary products including Impregon, a drug that has Albendazole for its active ingredient and is claimed to be effective against gastrointestinal roundworms, lungworms, tapeworms and fluke infestation in carabaos, cattle and goats.

Petitioner sued private respondent for infringement of patent and unfair competition before the RTC. It claimed that its patent covers or includes the substance   such that private respondent, by manufacturing, selling, using, and causing to be sold and used the drug Impregon without its authorization, (a) infringed Claims 2, 3, 4, 7, 8 and 9 of Letters Patent No. 145614 as well as committed (b) unfair competition under Article 189, paragraph 1 of the Revised Penal Code and (Section 29 of Republic Act No. 166 (The Trademark Law) for advertising and selling as its own the drug Impregon although the same contained petitioner’s patented Albendazole.

Private respondent averred that (a) Letters Patent No. 14561 does not cover the substance Albendazole (b) that even if the patent were to include Albendazole, such substance is unpatentable; (c) that the Bureau of Food and Drugs allowed it to manufacture and market Impregon with Albendazole as it’s known ingredient; and (d) Letters Patent No. 14561 is null and void, the application for the issuance thereof having been filed beyond the one year period from the filing of an application abroad for the same invention covered thereby, in violation of Section 15 of Republic Act No. 165 (The Patent Law); and that petitioner is not the registered patent holder.

The RTC dismissed the complaint and declared Letters Patent No, 14561 null and void for being in violation of Sections 7, 9 and 15 of the Patents Law.

The CA upheld the trial court’s finding that private respondent was not liable for any infringement of the patent of petitioner in light of the latter’s failure to show that Albendazole is the same as the compound subject of Letters Patent No. 14561. However, it declared that Letters Patent No. 14561 was not void as it sustained petitioner’s explanation that Patent Application Serial No. 18989 which was filed on October 8, 1976 was a divisional application of Patent Application Serial No. 17280. 

Petitioner argues that under the doctrine of equivalents for determining patent infringement, Albendazole, the active ingredient it alleges was appropriated by private respondent for its drug Impregon, is substantially the same as methyl 5 propylthio-2-benzimidazole carbamate covered by its patent since both of them are meant to combat worm or parasite infestation in animals. Petitioner thus submits that the appellate court should have gone beyond the literal wordings used in Letters Patent No. 14561, beyond merely applying the literal infringement test. 


(1) Whether or not private respondent committed patent infringement to the prejudice of petitioner.

(2) Whether or not doctrine of equivalents shall apply

(3) Whether or not Letters Patent No. 14561 was merely a divisional application of a prior application in the U. S. which granted a patent for Albendazole.


(1) NO. The burden of proof to substantiate a charge for patent infringement rests on the plaintiff. In the case at bar, petitioner’s evidence consists primarily of its Letters Patent No. 14561, and the testimony of Dr. Orinion, its general manager in the Philippines for its Animal Health Products Division, by which it sought to show that its patent for the compound methyl 5 propylthio-2-benzimidazole carbamate also covers the substance Albendazole. In Letters Patent No. 14561 no mention is made of the compound Albendazole.

When the language of its claims is clear and distinct, the patentee is bound thereby and may not claim anything beyond them. And so are the courts bound which may not add to or detract from the claims matters not expressed or necessarily implied, nor may they enlarge the patent beyond the scope of that which the inventor claimed and the patent office allowed, even if the patentee may have been entitled to something more than the words it had chosen would include.

It bears stressing that the mere absence of the word Albendazole in Letters Patent No. 14561 is not determinative of Albendazole’s non-inclusion in the claims of the patent. While Albendazole is admittedly a chemical compound that exists by a name different from that covered in petitioner’s letters patent, the language of Letter Patent No. 14561 fails to yield anything at all regarding Albendazole.

(2) NO. The doctrine of equivalents provides that an infringement also takes place when a device appropriates a prior invention by incorporating its innovative concept and, although with some modification and change, performs substantially the same function in substantially the same way to achieve substantially the same result. 

A scrutiny of petitioner’s evidence fails to convince this Court of the substantial sameness of petitioner’s patented compound and Albendazole. While both compounds have the effect of neutralizing parasites in animals, identity of result does not amount to infringement of patent unless Albendazole operates in substantially the same way or by substantially the same means as the patented compound, even though it performs the same function and achieves the same result. In other words, the principle or mode of operation must be the same or substantially the same.

The doctrine of equivalents thus requires satisfaction of the function-means-and-result test, the patentee having the burden to show that all three components of such equivalency test are met.

(3) As for the concept of divisional applications proffered by petitioner, it comes into play when two or more inventions are claimed in a single application but are of such a nature that a single patent may not be issued for them. The applicant thus is required “to divide,” that is, to limit the claims to whichever invention he may elect, whereas those inventions not elected may be made the subject of separate applications which are called “divisional applications.”24 What this only means is that petitioner’s methyl 5 propylthio-2-benzimidazole carbamate is an invention distinct from the other inventions claimed in the original application divided out, Albendazole being one of those other inventions. Otherwise, methyl 5 propylthio-2-benzimidazole carbamate would not have been the subject of a divisional application if a single patent could have been issued for it as well as Albendazole.

Explore more tags!

Administrative Law (5) Agency (4) article 36 (4) Article 153 of the Family Code (3) Bill of Rights (3) capital (4) Case Digest (327) Civil Code (20) civil law (56) Civil Procedure (49) commercial law (80) Conflicts of Law (33) Constitutional Law (25) court of appeals (9) Credit Transactions (7) criminal law (3) criminal procedure (9) Eminent Domain (4) family code (19) family home (4) income (5) income taxation (4) Insurance (54) Intellectual Property (6) japan (5) labor law (37) Law School (318) marriage (12) National Labor Relations Commission (7) negotiable instrument (10) Oblicon (19) Obligation and Contracts (25) Persons and Family Relations (21) Political Law (33) Ponente (7) property (8) Psychological Incapacity (4) Reinsurance (3) Remedial Law (56) situs (3) situs of taxation (3) Social justice (7) Sources of Labor Rights and Obligations (4) Succession (7) Taxation Law (6)