T 0529/97 (Apparatus for iontophoteric drug delivery/ALZA CORPORATION) 26-11-2001

Summary of Facts and Submissions

I. The appellant (patent proprietor) lodged an appeal against the decision of the opposition division, dispatched on 10 March 1997, revoking European patent No. 0 182 520. The notice of appeal was received on 19. May 1997 and the prescribed fee was paid on the same day. The statement setting out the grounds of appeal was received on 21 July 1997 (a Monday).

II. Pursuant to Article 100(a) EPC, the opposition was based on the grounds of lack of novelty and inventive step (Articles 52(1), 54 and 56 EPC).

III. Oral proceedings were held on 26 November 2001.

IV. The appellant requested that the decision under appeal be set aside and the patent be maintained on the basis of claims 1 to 16, pages 1 to 3, 3a, and 4 to 25 of the description and Figure 1 filed in the oral proceedings.

V. The respondent 1 (opponent 1) did not object to the appellant's request.

VI. The respondent 2 (opponent 2) was not represented at the oral proceedings, as previously announced by a letter received on 22 October 2001, but requested in writing that the appeal be dismissed.

The written submissions of the respondent 2 did not address the subject-matter of any claim of the appellant's present request.

VII. In the appeal proceedings reference was made inter alia to the following documents:

D1: Samarin, et al., Physicochemical Study of Iontophoresis, Voprosy Kurortologii, Fizioterapii i Lechebnoi Fizicheskoi Kul'tury, 1957, No. 4, pages 3 to 7, with English translation (pages 1 to 10);

D2: Chapter 12, "Iontophoresis", P.A. Rebinder, ed., pages 310 to 327, Moscow, USSR, Academy of Science, 1956, English translation (pages 1 to 30);

D4: US-A-4 474 570;

D5: US-A-4 383 529; and

D7: J. Allergy Clin. Immunol., vol. 52, No. 6, 1973, pages 328 to 333, R.H. Shereff et al., "Effect of beta adrenergic stimulation and blockade on immediate hypersensitivity skin test reactions".

VIII. Independent claim 1 reads as follows:

"1. An iontophoretic drug delivery apparatus comprising an iontophoretic drug delivery electrode assembly (10) itself comprising an electrode member (22,23) in electrical connection to a source (18,19,21) for an ionic drug species (19) to be delivered iontophoretically and for counterions therefor, said assembly containing at least one electrochemically active component which is oxidised or reduced during iontophoretic drug delivery or which oxidises or reduces other available species, in electrical connection to said source, and at least one of said electrochemically active component and said counterions being such that in the operation of said assembly generation of ionic species at said electrode member is substantially avoided or ionic species generated at said electrode member are substantially entirely converted by species present or generated in or at said source and/or said electrochemically active component into species having lower susceptibility to iontophoretic delivery from said assembly, characterised in that

said assembly comprises as said electrochemically active component said electrode member (22,23) which is a cathode which is silver chloride in contact with silver, said counterions for said ionic drug species (19) present in said source comprise silver ions,

and said source comprises a gel reservoir containing therein the ionic drug species (19) to be delivered iontophoretically,

whereby during operation of said assembly water electrolysis at said electrode member is substantially avoided."

Independent claim 4 is directed to an iontophoretic drug delivery electrode assembly having all the features included in the preamble of claim 1 and is characterised in that

" said assembly comprises as said electrochemically active component said electrode member (22,23) which is an intercalation compound or amalgam, whereby during operation of said assembly water electrolysis at said electrode member is substantially avoided."

Independent claim 12 is directed to an iontophoretic drug delivery electrode assembly according to the preamble of claim 4 and is characterised in that

" said assembly comprises as said electrochemically active component said electrode member (22,23) which is a silver, tin, zinc, nickel or manganese anode, and said drug counterions comprise ferrocyanide or ferricyanide ions, whereby during operation of said assembly water electrolysis at said electrode member is substantially avoided."

Independent claims 5 and 13 are directed to an iontophoretic drug delivery apparatus comprising an electrode assembly as claimed in claims 4 and 12, respectively.

IX. The appellant essentially relied on the following submissions:

The subject-matter of the amended claims was based on specific examples disclosed in the originally-filed claims and description. In particular, claim 1 was based on original claims 5 and 8, claim 4 was based on original claim 11, and claim 12 was based on technical information disclosed in the first paragraph of original page 11 of the description. Moreover, the claims were limited with respect in particular to claim 1 as granted.

The amendments clarified the nature of the electrochemically active component.

None of the documents of the cited prior art disclosed an apparatus or electrode assembly as defined in the independent claims or gave the skilled person an incentive to devise the claimed subject-matter.

X. In the contested decision (cf. point 2.7 of the reasons), the opposition division had noted that a claim which corresponded to present claim 1 would fulfil the requirements of the EPC and that no objections had been raised during opposition against the subject-matter of independent claims which corresponded to present claims 4 and 12.