 "Ethypharm receives patent for invention related to orally disintegrating pain killer, in India")
French pharmaceutical firm Ethypharm has received a favourable order for its patent application for granules and orally disintegrating tablets comprising pain killer Oxycodone as active ingredient, in India.
The Indian Patent Office has found the application in order for grant, as the company argued that its invention addressed a specific problem related to degradation of oxycodone in contact with an aminoalkyl methacrylate polymer.
The invention is related to taste-masked granules containing oxycodone, as well as orally disintegrating tablets comprising said granules and optionally acetaminophen. The patent application was filed in January, 2009.
The office raised objection in its First Examination Report including that the claims lack novelty and inventive step and that various other claims are not allowable under various sections of the Patents Act.
The company replied that in the course of preparing a new formulation containing oxycodone, it has discovered that the said active ingredient tends to be degrated by contacting an aminoalkyl methacrylate copolymer such as Eudragit E 100, which is commonly used as a taste-masking coating, in order to mask the bitter taste of the pill while it is inside the mouth. This problem has not been recognised before this and the discovery of it constitutes the patentable subject matter.
The invention proposes, in order to prevent the degradation of oxycodone within the granule, to apply a subcoat comprising a completely soluble in gastric fluids between the oxycodone coating and the taste masking coating units.
However, the response from the company on the objections in the FER were not been complied.
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Following this, the counsel of the company attended a hearing and argued that the problem of degradation of oxycodone regarding the aminoalkyl methacrylate copolymer has not been recognised in the prior art (the previous documents) and the efforts to make of this unrecognised problem constitute that patentable subject matter.
"Therefore, it is observed that in order to prevent the degradation of oxycodone within the granule, to apply a sub-coat comprising a compound soluble in gastric fluids between the oxycodone coating and the taste-masking coating comprising a polymer has never been identified in the prior art and since, said prior art never specifically mentions not to directly apply a coating such as an aminoalkyl methacrylate polymer, onto an active ingredient, such as an oxycodone as claimed are not obvious," argued the company.
Accepting the argument, N Ramchander, deputy controller of Patents & Designs, based on the amended claims, found the application in order for grant.
The company's patent specification explains that orally disintegrated tablets, which would dissolve in contact with saliva in less than sixty seconds without chewing action, are a convinent route suitable for ambulatory treatment, and for elderly or young children. It says that it is estimated that a large share of people experiences such diffculties.
The bitter taste is masked by a copolymer, sold by Rohm Pharma Polymers as Eudragit E100, but the company claims that it has discovered that this copolymer is not suitable for making conventional coated granules of direct tableting from Oxycodone. It added that the Oxycodone content of such granules, and in the comination of oxycodone and acetaminophen, tends to decrease with time due to the degradation of the active ingredient into by-products, while maintaining the quantity of oxycodone in the tablet even after several days after manufacturing is important. The company's invention addresses these issues, it claimed.