Integrating Public Health Concerns into Patent Legislation in Developing Countries
(2000; 140 pages) [French] [Spanish] View the PDF document
Table of Contents
View the documentTHE SOUTH CENTRE
View the documentFOREWORD
View the documentACKNOWLEDGEMENTS
View the documentGLOSSARY*
Open this folder and view contentsI. INTRODUCTION
Open this folder and view contentsII. PATENTABLE SUBJECT MATTER
Open this folder and view contentsIII. SCOPE OF CLAIMS
Open this folder and view contentsIV. PATENTABILITY REQUIREMENTS
Close this folderV. SPECIAL CASES IN PHARMACEUTICALS
View the documentV.1 Selection Patents
View the documentV.2 Prior Public Availability
View the documentV.3 Polymorphism
View the documentV.4 Analogy processes
View the documentV.5 Compositions
View the documentV.6 Optical Isomers
View the documentV.7 Active Metabolites
View the documentV.8 Prodrugs
Open this folder and view contentsVI. DISCLOSURE
Open this folder and view contentsVII. EXCEPTIONS TO EXCLUSIVE RIGHTS
Open this folder and view contentsVIII. EXAMINATION AND OBSERVATION PROCEDURES
Open this folder and view contentsIX. CLAIMS INTERPRETATION
Open this folder and view contentsX. COMPULSORY LICENSING
View the documentXI. FINAL REMARKS
View the documentREFERENCES
View the documentBACK COVER
 

V.3 Polymorphism

Some therapeutically active ingredients present polymorphic forms, that is, they may crystallize in diverse forms, which may have different properties that are more or less significant in terms of their therapeutic use. Independent patent applications on such forms100 have become frequent. Such forms can be deemed within the prior art - and therefore non-patentable - if they were inevitably obtained following the process of the basic patent on the active ingredient or were covered by a previous product patent.

100 For instance, “Form II olanzapine polymorph having a typical x-ray powder diffraction pattern as represented by the following interplanar spacings...(WO 96/30375).

Some companies have sought to use patentability of polymorphs as a means to extend the monopoly protection of a known active ingredient. For instance, SmithKline applied for a patent on a polymorph of cimetidine approximately five years after the original patent was granted. That patent, however, was nullified in the UK and other countries on the grounds that the polymorph was inevitably obtained by applying the process already claimed in the original patent101. Another example is the case of ranetidine. The patentee obtained in the United States a patent for a polymorph expiring in 2002 as opposed to 1995 for the main patent102.

101 See, e.g., Cook, Doyle and Jabbari, 1991, p. 89; Hansen and Hirsch, 1997, p. 113.

102 See, e.g. Cook, Doyle and Jabbari, 1991, p. 90; Grubb, 1999, p. 205.

The TRIPs Agreement also leaves ample freedom to Member countries to deal with this issue in their patent office administration. Patent offices should be aware of the possible unjustified extension of the term of protection arising from the successive patenting of the active ingredient and its polymorphs.

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