Basf Ag v Smithkline Beecham Plc

JurisdictionEngland & Wales
JudgeMr Justice Pumfrey
Judgment Date12 July 2002
Neutral Citation[2002] EWHC 1373 (Ch)
CourtChancery Division
Date12 July 2002
Docket NumberCase No: HC 01 C03268

[2002] EWHC 1373 (Ch)

IN THE HIGH COURT OF JUSTICE

CHANCERY DIVISION

PATENTS COURT

Royal Courts of Justice

Strand, London, WC2A 2LL

Before

The Honourable Mr Justice Pumfrey

Case No: HC 01 C03268

Between
Basf Ag
Claimant
and
Smithkline Beecham Plc
Defendant

Roger Wyand QC and Michael Tappin (instructed by Addleshaw Booth & Co) for the Claimant

Andrew Waugh QC, Justin Turner and Geoffrey Pritchard (instructed by Simmons & Simmons) for the Defendant

Hearing dates : 14, 15, 18–22 March 2002

Approved Judgment

I direct that pursuant to CPR PD 39A para 6.1 no official shorthand note shall be taken of this Judgment and that copies of this version as handed down may be treated as authentic.

Mr Justice Pumfrey Mr Justice Pumfrey

Mr Justice Pumfrey:

Introduction

1

This is an action to revoke United Kingdom patent GB 2297550 ('the patent in suit'), which stands in the name of the defendants ('SB'). The action came on for trial at the same time as another action to revoke the patent brought by Generics (UK) Limited. The latter proceedings were compromised on the day of the hearing, but SB relied on certain material introduced by Generics (UK) Limited in their proceedings to support their contentions as to the non-obviousness of the invention. I made certain orders intended to protect the confidentiality of this material, which originated from a company not a party to the proceedings at all, but permitted SB to rely on it.

The patent in suit

2

The patent in suit is concerned with a particular polymorphic form of a known pharmaceutical, paroxetine hydrochloride ('PHA'). This pharmaceutical is a 5-hydroxytryptamine uptake inhibitor sold in the United Kingdom under the name Seroxat, and is prescribed for depression, among other indications. It was among a number of drugs which were acquired by SB from Ferrosan, a Danish company, in the mid-1970's. Protection by patent and Supplementary Protection Certificate for the basic pharmaceutical expired in January 1999.

3

This case is about a particular form of PHA, called the anhydrate. This means that the crystals contain PHA only, and do not contain within their lattice structure either water (in which case they would be referred to as hydrates) or any other solvent (in which case they would be called solvates). In hydrates or solvates the molecules of water or other solvent occupy specific lattice points within the crystal lattice. They can be sought to be identified by using conventional analytical techniques.

4

The patent in suit is entitled 'Paroxetine hydrochloride anhydrate substantially free of bound organic solvent'. It was amended upon application to the Comptroller before these proceedings were started on 17 April 2001. One of the inventors, Mr Neal Ward, gave evidence before me. The case turns on difficult points of construction, and I make no apology for examining the specification in some detail. It starts with acknowledgment of EP-B-223403 ('403'), which is a patent granted to Beecham Group plc, SB's predecessor in title, claiming priority from GB 8526407 ('407') which is the principal item of prior art relied on. The patent in suit states (correctly) that Example 8 of '403 describes the preparation of PHA anhydrate by crystallisation from a water containing solvent. It calls the Example 8 material 'Form Z'. It then sets out the statement which is central to the present discussion:

'Subsequent repetition of the preparation described in Example 8 has failed to yield any type of paroxetine hydrochloride anhydrate, and there is no clear teaching elsewhere in the document of any alternative route or modification to the process which would generate the anhydrate.'

5

I shall return to this when I come to consider the case of obviousness advanced on the basis of '407, the disclosure of which differs somewhat from that of '403. A further disclosure is acknowledged at page 1 line 17:

'Paroxetine hydrochloride is also purported to be disclosed in the International Journal of Pharmaceutics 42, (1988) 135 to 143, published by Elsevier. The anhydrate is said to be produced by crystallising paroxetine hydrochloride from anhydrous propan-2-ol. Subsequent repetition of this process has resulted in a propan-2-ol solvate of paroxetine hydrochloride. That is to say that there is bound propan-2-ol in the product. This bound propan-2-ol cannot be removed by conventional drying techniques such as vacuum oven drying.'

6

The patent then states that paroxetine hydrochloride anhydrate substantially free of bound propan-2-ol has not been described in the literature, and identifies it as what the patent is about:

'Paroxetine hydrochloride anhydrate substantially free of bound propan-2-ol has not been described in the literature, nor has any method been disclosed which would yield such a product as an inevitable result. A method for preparing Paroxetine hydrochloride anhydrate substantially free of bound propan-2-ol has now been found.'

7

After a reference to four new forms of the anhydrate which have also been found, labelled Forms A, B, C and D, the specification continues:

'Accordingly, the present invention provides paroxetine hydrochloride anhydrate substantially free of bound organic solvent.

The present invention also provides paroxetine hydrochloride anhydrate substantially free of bound propan-2-ol with the proviso that it is other than Form Z.'

8

The phrase 'substantially free' is then explained:

'Substantially free of bound organic solvent is to be interpreted to be less than the amount of propan-2-ol which would remain solvated, i.e. bound, within the crystal lattice of the product under conventional vacuum oven drying conditions.'

9

On the face of it, this is intended to widen the scope of the words 'substantially free'. Given their natural meaning, they would suggest that any material with more than de minimis content of propan-2-ol would fall outside the claim. This meaning is displaced by the quoted sentence, whose effect is to require the phrase to be construed by reference to 'conventional conditions' for drying. There was a very substantial dispute as to what conditions, if any, could be described as conventional in this context. The further problem is that it defines the phrase 'substantially free of bound organic solvent' in terms of one organic solvent alone, propan-2-ol. So, if the preparation of paroxetine hydrochloride anhydrate takes place in (say) acetone in the absence of propan-2-ol, how is the reader of the specification to decide whether the result of his preparation in fact infringes?

10

It should also be observed that the passage refers to propan-2-ol 'solvated, i.e. bound, within the crystal lattice'. BASF relied on this passage as emphasising the manner in which the propan-2-ol was to be bound, viz. as solvent of solvation. I consider this submission further below.

11

There follows a statement about purity. Five preferred purity ranges (greater than 50%, 60%, 70%, 80% and 90%) are identified, and the most preferred being 'substantially pure', itself defined as more than 95% pure. The question of water and organic solvent is then revisited:

'It should be understood that the present invention comprising paroxetine hydrochloride anhydrate substantially free of bound propan-2-ol may contain unbound water, that is to say water which is other than water of crystallisation.'

12

This passage is concerned, it should be observed, not with organic solvents in general but with propan-2-ol in particular. The difference between unbound water and water of crystallisation is that the water of crystallisation occupies specific points in the crystal structure. Unbound water does not. Unbound water may be located elsewhere in the crystal. What matters is that in an infra-red spectrum of the crystalline material a peak characteristic of water free from any molecular interaction is detected, and that is what is meant by the presence of unbound water.

13

The specification then returns to the amount of bound organic solvent:

'Typically the amount of bound organic solvent on a weight for weight basis would be less than 2.0% preferably less than 1.8%, more preferably less than 1.5%, even more preferably less than 1.0%, yet more preferably less than 0.5% and most preferably less than 0.1%.'

I do not read this passage as limiting the scope of the monopoly set out by claim 1. The word 'typically' has the effect of giving an indication rather than setting a limit. The descriptions of the preferred crystalline forms is significant:

'Preferred forms of paroxetine hydrochloride anhydrate substantially free of bound propan-2-ol or substantially free of bound organic solvent include:

i) paroxetine hydrochloride anhydrate in Form A; (as hereinafter defined)

ii) paroxetine hydrochloride anhydrate in Form B (as hereinafter defined)

iii) paroxetine hydrochloride anhydrate in Form C; (as hereinafter defined)

iv) paroxetine hydrochloride anhydrate in Form D; (as hereinafter defined)'

14

The definitions of Forms A, B, C and D are lists of characterising features which follow the discussion of the characterising features of analytical data which distinguish the material 'substantially free of solvent' from other forms:

'The forms of paroxetine hydrochloride anhydrate may be distinguished from each other and the material formed as a result of carrying out the procedures mentioned in ['403] and the International Journal of Pharmaceutics 42, (1988), 135 to 143 by crystalline shape, solvent analysis, or techniques such as IR, melting point, X-ray diffraction, NMR, DSC, microscopy and any other analytical techniques which differentiate one form from another.' (page 3 lines 2–6)

15

The paper referred to is by Buxton Lynch and Rowe and was referred to as 'Buxton'. The analytical techniques listed in this passage are conventional. The abbreviations are for Infra-red...

To continue reading

Request your trial
4 cases
  • Paroxetine investigation: anti-competitive agreements and conduct
    • United Kingdom
    • Competition and Markets Authority (EW)
    • 12 Febrero 2016
    ...to a skilled person ‘having regard to any matter which formed part of the state of the art’. See BASF AG v SmithKline Beecham Plc [2002] EWHC 1373 (Ch). 45 BASF's response dated 16 August 2012 to the OFT’s informal request for information dated 26 July 2012 (document Case CE-9531/11 anhydra......
  • Paroxetine investigation: anti-competitive agreements and conduct
    • United Kingdom
    • Competition and Markets Authority (EW)
    • 12 Febrero 2016
    ...to a skilled person ‘having regard to any matter which formed part of the state of the art’. See BASF AG v SmithKline Beecham Plc [2002] EWHC 1373 (Ch). 45 BASF's response dated 16 August 2012 to the OFT’s informal request for information dated 26 July 2012 (document Case CE-9531/11 anhydra......
  • SmithKline Beecham Plc v Generics UK Ltd
    • United Kingdom
    • Court of Appeal (Civil Division)
    • 24 Julio 2003
    ...that about 2 litres of isopropanol would be added. SB's case was that the amount would be well below 1 litre. 6 In his judgment [2002] EWHC 1373 (Ch), the judge accepted the submission of SB and held that if the notional skilled person carried out example 1 of 407 he would not obtain PHA a......
  • Smithkline Beecham Plc v Apotex Europe Ltd (No. 3)
    • United Kingdom
    • Court of Appeal (Civil Division)
    • 29 Noviembre 2004
    ...of the patent were invalid, but that two claims (10(i) and 11) were valid. These proceedings were before Pumfrey J whose decision [2002] EWHC 1373 (Ch) was upheld by the Court of Appeal [2004] IP&T 846, [2003] EWCA Civ 87As a consequence of these findings SKB successfully applied to amend t......

VLEX uses login cookies to provide you with a better browsing experience. If you click on 'Accept' or continue browsing this site we consider that you accept our cookie policy. ACCEPT