T 0048/02 21-12-2005

I. The appeal lies against the decision issued 12 November 2001 of the opposition division to revoke European patent No. 0 613 678 (granted on European patent application No. 93 301 588.5 filed on 2 March 1993).

II. (a) As originally filed on application, claim 1 read:

"1. A composition for preventing and treating dental disease by reducing the number of micro-organisms in the mouth, said composition comprising an oral health preparation selected from the group consisting of a mouthwash and a dentifrice, wherein the oral health preparation contains stabilized chlorine dioxide in a concentration in the range of between about 0.005% - 0.5% and a phosphate compound in a concentration in the range of between about 0.02% - 3.0% to retard escape of chlorine dioxide from the composition at a pH in the range of 6.0 to 7.4, thereby increasing the shelf life and efficacy of the composition."

(b) On 23 June 1994 a new set of eleven claims was filed of which the independent claims 1 and 9 read:

"1. A composition in the form of a dentifrice or mouthwash for preventing and treating dental disease by reducing the number of micro-organisms in the mouth, said composition having a pH from 6.0 to 7.6 and comprising:

(i) stabilized chlorine dioxide in a concentration in the range of 0.005% - 0.5%; and

(ii) a phosphate compound in a concentration in the range of 0.02% - 3.0% to retard escape of chlorine dioxide from the composition thereby increasing the shelf life and efficacy of the composition."

9. Use of a phosphate compound at a concentration in the range of 0.2% to 3.0% to retard escape of chlorine dioxide from a mouthwash or dentifrice composition having a pH of from 6.0 to 7.6 and containing 0.005% to 0.5% by stabilised chlorine dioxide."

The accompanying letter stated that the new claims 1 and 9 were based on claim 1, page 14, first paragraph and Table 1 as originally filed.

(c) The examining division issued a communication dated 2 December 1996 under Rule 51(4) EPC indicating that it intended to grant a European patent on the basis of the text then on file, including the above claims 1 and 9.

(d) By a submission filed 3 April 1997 further amendments were requested to the claims and description. For ease of comparison the changes relating to claims 1 and 9 have been indicated below with omissions struck through, and additions in italics and underlined:

"1. A composition in the form of a dentifrice or mouthwash for preventing and treating dental disease by reducing the number of micro-organisms in the mouth, said composition [deleted: having a pH from 6.0 to 7.6 and ]comprising:

(i) stabilized chlorine dioxide in a concentration in the range of 0.005% - 0.5% by volume based on the total volume of the composition; and

(ii) a stabiliser comprising a phosphate compound in a concentration in the range of 0.02% - 3.0% by volume to retard escape of chlorine dioxide from the composition thereby increasing the shelf life and efficacy of the composition."

9. Use of a phosphate compound at a concentration in the range of [deleted: 0.2% ]0.02% to 3.0% by volume as a stabilizer to retard escape of chlorine dioxide from a mouthwash or dentifrice composition [deleted: having ]at a pH of from 6.0 to [deleted: 7.6 ]7.4 and containing 0.005% to 0.5% by volume stabilised chlorine dioxide."

On page 1 of the submission it was stated as regards the introduction of references to percentages by volume in the claims, that "The amount of phosphate and chlorine dioxide referred to in the claims relate to percentages by volume, as is readily apparent to a skilled person, and this has been clarified in the amended claims."

(e) The patent was granted with claims 1 and 9 in the form set out in paragraph (d) above without the examining division issuing any communication commenting on or raising objections to the amendments requested in the submission filed 3 April 1997.

III. Two notices of opposition were filed against the granted patent, in which revocation of the patent in its entirety was requested on the grounds of lack of novelty (opponent 1), lack of an inventive step (both opponents) and insufficient disclosure (opponent 1) according to Article 100, paragraphs (a) and (b) EPC, respectively. A ground of opposition under Article 100, paragraph (c) EPC was raised by opponent 1 after the expiry of the opposition term. By letter dated 7 July 2000 opponent 2 withdrew its opposition. During opposition inter alia the following documents were cited:

D1: US-A-4 574 084

D2: US-A-3 271 242

D11: Roberta R. Ratcliff, deposition made in United States infringement proceedings concerning US patents relating to subject-matter similar to the present European Patent.

IV. The main request before the opposition division related to the claims as granted, which included independent claims 1 and 9 (see also point II, paragraph d) above) reading:

"1. A composition in the form of a dentifrice or mouthwash for preventing and treating dental disease by reducing the number of micro-organisms in the mouth, said composition comprising:

(i) stabilized chlorine dioxide in a concentration in the range of 0.005% - 0.5% by volume based on the total volume of the composition; and

(ii) a stabiliser comprising a phosphate compound in a concentration in the range of 0.02% - 3.0% by volume to retard escape of chlorine dioxide from the composition thereby increasing the shelf life and efficacy of the composition."

9. Use of a phosphate compound at a concentration in the range of 0.02% to 3.0% by volume to retard escape of chlorine dioxide from a mouthwash or dentifrice composition at a pH of from 6.0 to 7.4 and containing 0.005% to 0.5% by volume stabilised chlorine dioxide."

The opposition division admitted into the proceedings for its relevance the objection under Article 100(c) EPC in relation to the claimed concentration range of stabilized chlorine dioxide. It found that there was no explicit mention in the description as originally filed for the specification of this concentration range being by "volume based on the total volume of the composition" nor to the specification with respect of the concentration range of phosphate being "by volume".

Furthermore, inspection of the examples did not allow any conclusion as to whether the concentration range of stabilized chlorine dioxide given in % was to be referred to the total volume of the composition or not. Moreover, the skilled person would seriously contemplate other possibilities such as based on the basic composition instead of the final composition, and the corresponding alternatives "by weight". It could not be derived directly from the application as filed whether the concentration of stabilized chlorine dioxide was measured by weight or volume. Among the materials to be used as starting materials was mentioned "Purogene (2% chlorine dioxide)" (cf. page 13, line 10 of the patent specification), but this piece of information did not allow one to conclude that the "composition in the form of a dentifrice or mouthwash" as claimed in claim 1 comprised a stabilized chlorine dioxide in "a concentration in the range of 0.005% - 0.5% by volume based on the total volume of the composition".

The specification of the concentration range of the phosphate compound as "by volume" was unusual having regard to the fact that the phosphate compound was a solid. Additionally, this specification "by volume" might very well refer to the volume of either the basic composition or the final composition. Insofar, the said expression introduced an information "by volume" instead of "by weight" which could not be derived from the application as filed.

The opposition division decided that the above analysis also applied to the use claim 9 and other claims. Therefore the claims as granted incorporated subject-matter which was not directly and unambiguously derivable from the application documents as originally filed, and the main request was to be rejected since its subject-matter extended beyond the contents of the application as originally filed (Article 100(c) EPC).

V. The first auxiliary request before the opposition division comprised amended claims, including the following, where omissions compared to the claims as granted are shown struck through, and additions are shown underlined and in italics:

"1. A composition in the form of a dentifrice or mouthwash for preventing and treating dental disease by reducing the number of micro-organisms in the mouth, said composition comprising:

(i) stabilized chlorine dioxide in a concentration in the range of 0.005% - 0.5% (50 - 5000 ppm) [deleted: by volume based on the total volume of the composition ]; and

(ii) a stabiliser comprising a phosphate compound in a concentration in the range of 0.02% - 3.0% weight by volume to retard escape of chlorine dioxide from the composition in the absence of a peroxy compound at a pH of 6.0 to 7.4 thereby increasing the shelf life and efficacy of the composition, with the proviso that the composition is not a mouthwash having 0.1 % (1000 ppm) stabilized chlorine dioxide and 0.2% weight by volume of trisodium phosphate."

9. Use of a phosphate compound at a concentration in the range of 0.02% to 3.0% weight by volume as a stabilizer to retard escape of chlorine dioxide from a mouthwash or dentifrice composition in the absence of a peroxy compound at a pH of from 6.0 to 7.4 said composition containing 0.005% to 0.5% (50 - 5000 ppm) [deleted: by volume ]stabilised chlorine dioxide."

The opposition division held that in claim 1 the deletion of "by volume based on the total volume of the composition", and in claim 9 the deletion of "by volume", as specification of the range of the percentages for the concentration of the stabilised chlorine dioxide lead to an extension of the protection conferred, since now the claims encompassed compositions (and their uses) having other concentration values than those granted and which did not fall within the granted scope but were more broadly defined. Further, the introduction of the range in ppm in brackets did not correspond to a restriction but also broadened the scope, since ppm was a relative and not an absolute term and no reference was given (by weight, by volume or based on the total or partial compositions).

The opposition division also held that the introduced feature of "in the absence of a peroxy compound" in claims 1 and 9 by way of disclaimer to re-establish novelty over D1, and of the proviso at the end of claim 1 by way of disclaimer to re-establish novelty over D11 contravened Article 123(2) EPC, as such disclaimers would only be justifiable over accidental disclosures which would not be relevant when considering inventive step, whereas D1 and D11 remained relevant for this.

The proviso "in the absence of a peroxy compound" further was unclear and seemed to be in contradiction with the teaching of the patent, so that Article 84 EPC was not complied with.

The opposition division thus rejected the first auxiliary request as not meeting the requirements of Article 123(2) and (3) as well as Article 84 EPC.

VI. The second auxiliary request before the opposition division comprised a claim 1 identical to claim 9 of the first auxiliary request, and thus this request too was rejected by the opposition division as not meeting the requirements of Articles 123(2) and 3 and Article 84 EPC, as the same objections applied to its claim 1 as applied to claim 9 of the first auxiliary request.

VII. On 11 January 2002, the proprietor (appellant) filed a notice of appeal against the above decision, the prescribed fee being paid on the same day. The statement setting out the grounds of appeal was filed on 19 March 2002.

VIII. By letter of 20 October 2005, in response to a communication of the board, the appellant submitted three new sets of claims (auxiliary requests 1 to 3) and requested further amendments to those requests in the form of incompletely formulated requests 4 to 6. Moreover, further documents were cited inter alia:

D14: Bio-Cide International Corporate Offices "Purogene" product information, www.bio-cide.com, 2 pages.

IX. By letter of 21 October 2005, the appellant submitted a declaration of an expert witness, Dr. William Cooley, (D17) dated 21 October 2005. This contained inter alia the following passages:

"...

2. In all my extensive experience of working in the field of oral hygiene products, the industry standard for the measurement of concentrations of compounds forming parts of toothpaste has always been (and remains to this day) the concentration in terms of weight, for example percent by weight.

3. Hence it is my opinion that a person working in the field of mouthwashes would always read the term "percent" given in relation to a concentration of an ingredient of such products as "percent by weight".

4. Furthermore it is my opinion that the skilled person on seeing the use of percent by volume to describe the concentration of a solid such as phosphate or stabilized chlorine dioxide, would assume that a mistake had been made and that percent by weight was the intended measurement.

5. My opinion is supported by the United States Code of Federal Regulations in relation to labelling requirements for over the counter drugs...."

X. Oral proceedings were held on 21 December 2005. At the oral proceedings, the appellant submitted a corrected main request (claims 1 to 12) corresponding to claims 1 to 12 filed as auxiliary request 1 on 20 October 2005, and an amended set of claims 1 to 10 as auxiliary request 1A.

XI. Claims 1 and 9 of the main request are as set out below with omissions compared to the claims as granted shown struck through, and additions shown underlined and in italics:

"1. A composition in the form of a dentifrice or mouthwash for preventing and treating dental disease by reducing the number of micro-organisms in the mouth, said composition comprising:

(i) stabilized chlorine dioxide in a concentration in the range of 0.005% - 0.5% weight by volume based on the total volume of the composition; and

(ii) a stabiliser comprising a phosphate compound in a concentration in the range of 0.02% - 3.0% weight by volume to retard escape of chlorine dioxide from the composition at a pH of from 6.0 to 7.4 thereby increasing the shelf life and efficacy of the composition."

"9. Use of a phosphate compound at a concentration in the range of 0.02% to 3.0% weight by volume as a stabiliser to retard escape of chlorine dioxide from a mouthwash or dentifrice composition at a pH of from 6.0 to 7.4, said composition containing 0.005% to 0.5% weight by volume stabilised chlorine dioxide."

XII. Claims 1 and 7 of auxiliary request 1A are as set out below with omissions compared respectively to the claims 1 and 9 as granted shown struck through, and additions shown underlined and in italics:

"1. A composition in the form of a dentifrice or mouthwash for preventing and treating dental disease by reducing the number of micro-organisms in the mouth, said mouthwash composition comprising:

(iii) stabilized chlorine dioxide in a concentration in the range of 0.005% - 0.5% weight by volume based on the total volume of the composition; and

(iv) a stabiliser comprising a phosphate compound in a concentration in the range of 0.02% - 3.0% weight by volume to retard escape of chlorine dioxide from the composition at a pH of from 6.0 to 7.4 thereby increasing the shelf life and efficacy of the composition;

or said dentifrice composition comprising:

(v) stabilized chlorine dioxide in a concentration in the range of 0.005% - 0.5% weight by volume based on the total volume of the composition; and

(vi) a stabiliser comprising a phosphate compound in a concentration in the range of 0.02% - 3.0% weight by weight to retard escape of chlorine dioxide from the composition at a pH of from 6.0 to 7.4 thereby increasing the shelf life and efficacy of the composition."

"7. Use of a phosphate compound at a concentration in the range of 0.02% to 3.0% weight by volume in a mouthwash and 0.02 to 3.0% weight by weight in a dentifrice as a stabiliser to retard escape of chlorine dioxide from [deleted: a ]the mouthwash or dentifrice composition at a pH of from 6.0 to 7.4, said composition containing 0.005% to 0.5% weight by volume stabilised chlorine dioxide."

XIII. The other auxiliary requests remained as submitted with letter of 20 October 2005.

Auxiliary request 1 corresponds to the main request.

Auxiliary request 2 has a claim 1 corresponding to claim 1 of the main request but with the words "or mouthwash" deleted.

Auxiliary request 3, has a claim 1 corresponding to claim 9 as granted (see point IV above)

Auxiliary request 4 amounts to four different requests, corresponding to the main request, auxiliary request 1A, auxiliary request 2, and auxiliary request 3 each modified by replacing the term "stabilizer" in claim 1 and the respective independent use claim by the term "activating inhibitor".

Auxiliary request 5 amounts to eight different requests, corresponding to the main request, auxiliary request 1A, auxiliary request 2, and auxiliary request 3, and the four requests of auxiliary request 4, each respectively modified so that the independent claims are additionally limited to a phosphate selected from mono- or dibasic sodium phosphate, or trisodium phosphate.

Auxiliary request 6 amounts to eight different requests, corresponding to the main request, auxiliary request 1A, auxiliary request 2, and auxiliary request 3, and the four requests of auxiliary request 4, each modified so that all claims are limited to trisodium phosphate.

XIV. The appellant argued in substance as follows:

(a) The main request involved corrections under Rule 88 EPC. According to the examples as filed, stabilized chlorine dioxide was used in the form of "Purogene" which was a solid sodium chlorite as shown in the product specification of "Purogene" (D14). Thus, a 2 % solution of Purogene would be understood by the skilled person to be 2 g of sodium chlorite in 100 ml aqueous solution. Furthermore, the indication of a concentration by "weight by volume" was in accordance with industrial standards. The final concentration of the exemplified compositions referred to 100 ml and thus to a volume basis. Similar arguments applied to the phosphate which was a solid and was used in example 1 of the application as filed in % by weight based on the total volume of the composition. Since both ingredients of the compositions were solids, the skilled person would immediately recognize that a mistake had been made. In addition, it was immediately evident that nothing else would have been intended than what was offered as the correction. Thus, the corrected concentration "% weight by volume" was admissible.

(b) The amendment of feature (i) in claim 1 of the main request, auxiliary request 1A and auxiliary requests 1 and 2 was based on example 1 of the application as filed, from which it could be derived that the stabilized chlorine dioxide referred to solid sodium chlorite in 100 ml solution. Thus, that amendment was allowable under Article 123(2) EPC.

As regards the phosphate concentration in feature (ii) of claim 1, the opposition division had already accepted the proposed amendment as allowable (Article 123(2) EPC). Furthermore, the concentrations of the phosphate indicated in the examples showed that the indication "by weight" was correct. This was confirmed by D17. Thus, the amendments were allowable under Article 123(2) EPC.

Furthermore, the amendment narrowed the scope of protection and hence claim 1 met the requirements of Article 123(3) EPC.

(c) Claim 1 of auxiliary request 3 was identical to claim 9 as granted. The term "stabiliser" used in claim 1 of auxiliary request 3 was derivable from the application as filed. Furthermore, the concentrations referred to "% by volume" could be derived from example 1 of the application as filed. Any clarity objections which might arise with respect to those terms should be disregarded, since clarity was no opposition ground under Article 100 EPC.

(d) With respect to auxiliary requests 4 to 6, the appellant relied essentially on his submissions concerning the main request and auxiliary requests 1A and 1 to 3, the modifications introduced in the requests forming auxiliary request 4 being made in case the Board considered that there was no basis for the phrase "stabiliser comprising a phosphate compound", and the modifications introduced in the requests forming auxiliary request 5 and 6 serving to restrict the claims to distinguish the subject-matter claimed therein further from the prior art.

XV. The arguments of the opponent (respondent), can be summarized as follows:

(a) In granted claim 1 the term "% by volume based on the total volume of the composition" for defining the concentration of the stabilized chlorine dioxide was not an evident error, since chlorine dioxide was a gas and the total content thereof could refer to 100 % by volume. Furthermore, there were four alternatives to correct the percentage of the stabilized chlorine dioxide so that it was not immediately evident that the proposed correction was the only possible one.

(b) The percentage of phosphate in the dentifrice referred to "weight", but not to "volume" as was stated by D17 so that the correction was not evident. Thus, the requirements of Rule 88 EPC were not fulfilled.

(c) The limitation in granted claim 1 to the term "by volume" for the concentrations of phosphate and chlorine dioxide was not disclosed in the application as filed. The same objection applied to the term "based on the total volume of the composition". Furthermore, the term "stabiliser" mentioned in granted claims 1 and 9 was not disclosed in the application as filed. The amended feature "% weight by volume" (emphasis added) in the claims of the main request would not overcome the above deficiencies in the claims since there was no basis for that amendment in the application as filed. Thus, the claimed subject-matter of the corrected main request did not meet the requirements under Article 123(2) EPC. Furthermore, the amended feature "% weight by volume..." resulted in an extended protection (Article 123(3) EPC).

(d) Since the amendments to feature (i) of claim 1 in auxiliary requests 1A, 1 and 2 were identical to those in claim 1 of the main request, the same arguments as brought forward with respect to the main request applied mutatis mutandis (Article 123(2) and (3) EPC).

(e) Claim 1 of auxiliary request 3 corresponded to claim 9 as granted. However, that claim had no basis in the application as originally filed. The appellant failed to show the basis for each of the claimed features, in particular for the terms "% by volume" and "stabiliser". Since the concentrations of essential components of a composition always had a technical meaning, the present undisclosed limiting features were not allowable (decision G 1/93 (OJ EPO, 1994, 541).

In addition, example 1, on which the appellant relied, related to a solution and not to a dentifrice so that it could not provide a basis for the term "% by volume" for the dentifrice of claim 1 of auxiliary request 3.

(f) The additional amendments according to auxiliary requests 4 to 6 were not suitable to overcome the objections under Article 123(2) and (3) EPC.

XVI. The appellant requested that the decision under appeal be set aside and that the patent be maintained

on the basis of the main request or auxiliary request 1A submitted at the oral proceedings on 21 December 2005, or of one of auxiliary requests 1 to 6 submitted on 20 October 2005.

XVII. The respondent requested that the appeal be dismissed.