Sandoz Patents Ltd. v. Gilcross Ltd.

The judgment of the Court was delivered by

These last-mentioned claims, as I see it, cannot stand as claims in respect of any inventive step involved in the mixture of a substance with a carrier since there is no invention involved in such a step. Vide Commissioner of Patents v. Farbwerke Hoechst A.G. (1964 S.C.R. 49).

The condensation can be carried out, for example, by dissolving a phenothiazine derivative of formula II, which is substituted in 3-position by a monovalent sulfur-function, in a suitable organic solvent such for example as benzene, toluene or xylene, and then reacting the dissolved phenothiazine derivative with an ω-halogen-alkyl-amine of formula III at room temperature or at elevated temperature in the presence in the reaction mixture of an alkaline condensing agent, such for example as sodium hydroxide, potassium hydroxide, sodamide, metallic sodium, lithium hydride, sodium tert.-butylate, etc., i.e. an alkali

metal or a compound thereof such as the hydroxide, amide, hydride or alkanolate.

The reaction can also be carried out in the absence of a solvent, by fusing the reaction partners together; in this case it is possible also to omit the condensing agent, although this may reduce the yield.

Upon conclusion of the reaction, the reaction mixture is shaken out with water, and the solvent evaporated off under reduced pressure; however, the new compounds can also be extracted from the reaction mixture by dilute mineral or organic acids and precipitated from the aqueous phase by the addition of caustic alkali or ammonia. The bases can be filtered off in those cases where they separate out of the solid state or, where they separate out as oils, can be taken up in benzene or another water-immiscible solvent and then again freed of solvent by evaporation. The bases can be purified by distillation in a high vacuum and can be converted into appropriate salts with organic or inorganic acids.

This is all that the specification contains by way of a description of how to prepare thioridazine by use of the bromo-ethane starting material though as previously mentioned, the preparation of thioridazine by the use of the chloro-ethane starting material is described in detail in Example 1 as an illustration of the general process and the sufficiency of this as a description of the chloro-ethane process is not challenged. There is thus in the specification a general description of a procedure for the production of a large class of substances consisting of an identification of the type of chemical procedure to use, i.e., condensation of material of one type with material of another type, plus a general description of how the procedure may be carried out as applied to the numerous materials of the two types. Thioridazine is one of the substances comprised in the group that may be so prepared. The bromo-ethane starting material is a member of one of the two types of starting materials and it may be condensed with the appropriate member of the other type of starting material, which however is not named, to produce thioridazine. The general description of the procedure for carrying

out the condensation is not, however, confined to that in which the bromo-ethane starting material is used or to that in which either the bromo-ethane or the chloro-ethane starting materials are used to produce thioridazine. In consequence and as appears from the evidence not all the general descriptive matter would be appropriate to either of such processes and without more detailed description of them it would be necessary for a chemist to apply his knowledge to select from the general description appropriate reaction conditions, solvents, condensing agents and acids to carry out the procedure. For example, in the application of the bromo-ethane process to the production of thioridazine one of the solvents and one of the condensing agents mentioned in the general description would not work. In the case of the chloro-ethane process further information is given in Example 1 as an illustrative example of the whole general process but nowhere is the same detailed information given with respect to the bromo-ethane process either by reference to that given in the description of the chloro-ethane process in Example 1 or otherwise.

In this situation Dr. Baer gave evidence that it is well known to chemists that in such a chemical reaction a bromo-ethane compound could be expected to behave in a way that was analogous or similar to that of the corresponding chloro-ethane compound unless some anomaly in the behaviour of the bromo-ethane compound in the reaction had been reported. He himself, on the instructions of the defendant’s solicitors, had in fact prepared thioridazine after examining literature published prior to the material time but without having seen the specification or what was in it, using the chloro-ethane starting material and some time later, after having seen the specification, he had prepared thioridazine using the bromo-ethane starting material and his general knowledge of organic chemistry plus that gained in the earlier test, and he experienced no difficulty that in his opinion could not have been “tackled” by an undergraduate university student in organic chemistry.

It also appears from his evidence that he obtained no help in carrying out the bromo‑ethane process from the description in the specification, which in fact appears to have added nothing to the general chemical knowledge of how to condense materials of the defined types to produce substances of the defined class.

Dr. Wright on the other hand while expressing the opinion that the preparation of thioridazine, as far as the chemistry is concerned, required nothing more than chemical skill, and would have been obvious to anyone familiar with what was generally known in April 1956 about the chemistry of phenothiazines took the view that the number of significant variables such as the reaction temperature, the reaction rate, the particular solvent to be used, the specific condensing agent, if any, and the quantity thereof and others was such that a great deal of time and effort would be required to find a way to successfully produce thioridazine by the bromo-ethane process in the absence of a detailed description of how to do it.

While I think that the ease with which Dr. Baer succeeded might not necessarily be experienced by everyone who would fit the description of a skilled chemist it appears to me that the general description in the specification coupled with the detailed description of the chloro-ethane process as an illustrative example, would in effect serve to remind a chemist of what he already knew that is to say that a bromo-ethane process could probably be carried out in a similar way bearing in mind known differences in bromo‑compound reactions from chloro-compound reactions, and that the addition of a detailed description of the bromo-ethane process would in fact not have done much to enhance the knowledge of or assist a qualified chemist in carrying out the process.

On the other hand the requirement of section 36(1) is that the applicant describe his invention and its operation or use as contemplated by him. The public and the reader are entitled to a description of the invention which the inventor has made and to say that a group of substituted phenothiazines may be made by a known type of chemical reaction is, as I see it, to assert merely what is already known as a general proposition rather than to say that he has carried it out in a particular way using particular materials and found that such is a practical method of producing an unexpectedly useful new substance known as thioridazine. I think moreover that Mr. Goldsmith is right in his contention that if the inventors did not carry out the bromo-ethane process they were not entitled to claim it and that if in fact they had carried it out it would have been a simple matter to describe it as they did in the case of the chloro-ethane process by a description that would give the reader precisely what was involved in their invention of the bromo-ethane process.

That seems to me to be the standard of description which Fletcher Moulton, L.J. had in mind when he said in British United Shoe Machinery Company Ltd. v. A. Fussel & Sons Ltd. (1908) 25 R.P.C. at p. 650, which was cited by counsel for the defendant:

As it is the duty of the inventor to give the fullest practical information to the public he is bound to put in, if, for instance the invention is a process, quantities and times which are the best he knows.

Mr. Smart submitted that the invention was thioridazine and that by giving details of the chloro-ethane process the inventors were describing the best way known to them of obtaining the benefit of the invention but this as I see it ignores the fact that the bromo‑ethane process is a separate process which is a separate aspect of the invention, which has its own optimum conditions and which is separately claimed. It is I think necessary to bear in mind as well that if the bromo-ethane process was in fact invented by these inventors they must not only have carried if out but must have been the first to do so and that ex hypothesi no description of it could be available to the public in published literature. It seems to me therefore that the requirement of the statute that the applicant correctly and fully describe his invention and its operation or use as contemplated by the inventor is not fulfilled in respect of a process such as this by a specification which does not describe the particular process itself and which thus neither describes fully what has been invented nor describes its use as contemplated by him. Even though with the knowledge available and without exercising inventive ingenuity a chemist could have devised a method of preparing thioridazine by a condensation procedure involving the use of bromo-ethane starting material and the appropriate phenothiazine derivative the public is, I think, entitled to be told what method the applicant devised and employed upon which he bases his claim for a monopoly of that process. Here while the presence in the specification of a claim for the bromo-ethane process suggests that it is part of the invention of thioridazine and processes for its production the description of the invention does not even contain a bare statement (as it does in the case of the salts) that thioridazine may be prepared by a procedure essentially similar to that described in Example 1 by the condensation of 3 methyl‑mercapto-phenothiazine with the bromo-ethane starting material. Accordingly, though not without some doubt, I shall hold that the claims in respect of the bromo‑ethane

process or dependent upon it, that is to say, claims 1, 3, 5, 7, 9, 10 and 11 are invalid.

I should add that I reach this conclusion somewhat less hesitantly than I otherwise might do, on reflecting that inventors who after making an invention which consisted of thioridazine and two processes for its preparation, one of which was by the use of a bromo-ethane starting material, instead of describing what they have done, have described as their invention a class invention which they have not invented at all, have themselves to blame if their general description is regarded as being simply what it purports to be, that is to say, a description of the alleged class invention rather than of their actual invention of a particular process for the manufacture of thioridazine. It has often been said that patent specifications are not exercises in composition and that a court will strive to uphold when it can patents for meritorious inventions. But this cannot be carried to the point of disregarding what seems to me to be a specific requirement of the statute. Nor, with patent counsel to help, should the composition of a proper description of what has in fact been invented be a task so difficult that the result should be that no description at all of a substantial portion of the actual invention is to be found in the specification though the specification is replete with description of what the applicants did not invent and though the specification has obviously been prepared with a good deal of care. (Italics added.)

In the present case, as a matter of first impression, the specification purports to describe one invention, that of a class of substances, and to assert utility for all members of the class. Anyone skilled in the art would not, however, think for a moment that all members of the class had been prepared and tested but would, I think, regard the assertion as nothing but a hypothesis.

I agree with the submission of counsel for the plaintiff that claims for the specific substance, thioridazine, do not fit the character of the alleged class invention but when such claims are in fact found in a

specification the specification itself takes on a different meaning from what it might otherwise have and, as I see it, it then becomes necessary to give it a practical interpretation so far as that is possible.