By Evarist Baimu Nyaga Mawalla - Home

A company (Cyanamid) register a patent in the united kingdom for the use asabsorbable surgical sutures of filaments made of particular kind of chain polymerknown as a polyhydroxyacetic ester (PHE) the sutures were of a kind thatdisintegrated and were absorbed by the human body once that had saved theirpurpose the priority date of the patent was 2 nd October 1964. At that date theabsorbable sutures commonly in use were made from catgut. A rival companyethical were the main suppliers of catgut sutured in the United kingdomCyanamid introduced their patented product in 1970 and by 1973 had capturedsome 15 per cent of the United Kingdom market for absorbable surgical suture.In order to meet the competition from Cyanamid, Ethic on proposed to introducetheir own artificial suture (ALG) the chemical substance of which PHAE wasmade was a photopolymer whereas the substance of which XLG was made wasa copolymer. InHLAmerican Cyanamid v Ethicona. March 1973 Cyanamid brought a quiet timer action against Ethicon,claiming an injunction to restrain a threatened infringement of their patentby supplying XLG sutures to the surgeons in the United Kingdom , andgave notice of motion for an interlocutory injection At the hearing of themotion a large body of conflicting affidavit evidence was advance by bothparties on the issue whether the use of XLG as an absorbable surgicalsuture would constitute an infringement of Cyanamid ‘sb. Patent. The patent judge held that on the available evidence Cyanamidhad made out a strong prima facie case against Ethicon and that on abalance of convenience an interlocutory injection on an undertaking indamages by Cyanamid, should be granted to maintain the status quobetween the parties pending the trial of the action. On appeal, the Courtof Appeal reversed that decision on the ground that on the evidenceCyanamid had not made out a prima facie case of infringement andc. That there was a well established rule of la hat a court was precluded fromgranting an interlocutory injunction or from considering the balance ofconvenience between the parties unless the evidence adduced at thehearing of the application satisfied the court on the balance of probabilities297