has used (Gentiruco AG v Firestone SA (Pty) Ltd 1972 (1) SA 589 (A) at 614BC) what is sought by a purposive
construction is to establish what were intended to be the essential elements, or the essence, of the invention,
which is not to be found by viewing each word in isolation but rather by viewing them in the context of the
invention as a whole. To the extent that it might have been suggested in an obiter dictum in Nampak Products
Ltd and another v ManDirk (Pty) Ltd2 1999 (3) SA 708 (SCA) at 714A
Page 143 of [2002] 4 All SA 138 (SCA)
that it might be called in aid only to construe an ambiguous claim I do not think that is supported by the
decisions of this Court and in my view it is not correct. It is merely an approach to construction that is aimed at
establishing what was meant in a particular context. As pointed out by Hefer JA in Fundstrust (Pty) Ltd (in
Liquidation) v Van Deventer3 1997 (1) SA 710 (A) at 726H727B (in a passage that was adopted in relation to
the construction of patent specifications in Monsanto Co v MDB Animal Health (Pty) Ltd (formerly MD Biologics CC
2001 (2) SA 887 (SCA) at 892BC):
"The task of the interpreter is, after all, to ascertain the meaning of a word or expression in the particular context
of the statute in which it appears (Loryan (Pty) Ltd v Solarsh Tea and Coffee (Pty) Ltd 1984 (3) SA 834 (W) at
846G ad fin). As a rule every word or expression must be given its ordinary meaning and in this regard lexical
research is useful and at times indispensible. Occasionally, however, it is not."
[10] The words "excipients" and "compounds" in paragraph (b) of the claim, expressed as they are in the plural,
might indeed in literal terms mean at least two different excipients, or compounds, as the case may be (the
literal meaning was adopted by the Commissioner). But when seen in the context of the invention as a whole,
and also when seen in the context of one of the remaining claims, in my view it is most doubtful that the
inventor could have intended that to be essential.
[11] The purpose that is served by the subcoating layer or layers (for convenience I will refer hereafter to the
subcoating layer or layers only in the singular) is merely to form an effective but watersoluble barrier between
the alkaline core and the enteric coating. It is apparent from the claim itself that the chemical composition of
the subcoating layer was considered by the inventor to be immaterial, provided only that it fulfilled the
functional requirements specified in the claim, for the claim does not insist upon, or even specify, what its
chemical composition should be. If the subcoating layer may consist of a mixture of any two
View Parallel Citation
excipients or��compounds it must follow that its composition is immaterial (provided only that it has the
functional characteristics specified in the claim) and there is then no apparent reason, nor could one be
suggested, why it should not consist of any one of those compounds alone. The fact alone that the inventor
was indifferent to the composition of the subcoating layer (provided only that it had the characteristics
described in the claim) makes it most doubtful that it was intended that two or more excipients or compounds
were essential elements of the invention.
[12] Moreover, that doubt only increases when the words are read in the context of claims 3 and 4 (which indirectly
incorporate all the elements of claim 1). Claims 3 and 4 provide as follows:
"3. A preparation according to claim 1 wherein the subcoating comprises two or more sublayers.
4.
A preparation according to claim 3 wherein the subcoating comprises hydroxypropyl methylcellulose,
hydroxypropyl cellulose or polyvinylpyrrolidone."
[13] A preparation according to claim 4 will have a subcoating that comprises at least two layers, but those
subcoating layers will nonetheless conform
Page 144 of [2002] 4 All SA 138 (SCA)
with paragraph (b) of claim 1. It will be a subcoating, however, that might "comprise" any one of the three
compounds described in claim 4. If the word "comprise", as it is used in claim 4, was intended to mean
"consists of", then clearly claim 1 was not intended to exclude a subcoating consisting of only one compound,
for otherwise the provisions of claim 4 would be internally inconsistent. It was submitted by the respondent,
however, that the word "comprises" in claim 4 is used as a synonym for "includes" (which would not be
inconsistent with modern usage Fowler's Modern English Usage 3ed by RW Burchfield and is also the meaning
that has been accepted in patent cases in the United States see In re Bertsch 56 USPQ 379 at 384; HK Porter
Company, Inc v The Gates Rubber Company 187 USPQ 692 at 715) and that claim 4 thus does no more than
specify that the multiple compounds that are required by claim 1 are to include at least one of the compounds
specified in claim 4. Whether the word "comprise" is used in claim 4 synonymously with "includes" is itself
questionable, for that would seem to be inconsistent with its use in claim 3, but it is not necessary for present
purposes to decide whether that is so.
[14] In my view both those considerations, if not decisive of the meaning to be given to the words in the claim, at
least raise considerable doubt that the inventor intended to exclude from the ambit of the claim preparations in
which the subcoating layer consists of one compound, notwithstanding the use of the word in the plural.
Where the words used in the claim are ambiguous, in the sense that when read in their proper context their
meaning is doubtful or not reasonably clear, the body and title of the specification may be invoked to ascertain
whether at least a reasonably certain meaning can be given to the claim (Gentiruco AG v Firestone SA (Pty) Ltd
1972 (1) SA 589 (A) at 615FG).
[15] The description of the invention in the body of the specification