Drug formulation patentability

PSL wong, F Theeuwes, BL Bailey, MH Desley. Osmotic dosage system for delivering a formulation comprising liquid carrier and drug. US Patent 5,324,280, 1995. 

The patents eovering the 22 brand-name drug produets in whieh the generic applicant prevailed involved formulation or method of use patents. In 3 instances (out of 6 where a drug substanee patent was at issue), a drug substanee patent was found invalid or not infringed. 

Patents Not Claiming the Approved Drug Substance, Drug Formulation or Use... 

An examination of two listed product-by-process patents illustrates this latter point. Patent Nos. 6,063,927 (the 927 patent) and 6,172,233 ( 233) both claim paroxetine hydrochloride made according to specified processes. In each case, the patent itself acknowledges that paroxetine hydrochloride was well known at the time the brand-name company applied for the patents. The brand-name company represented to the Patent Office in the patent document that the recited process was new and made the claims patentable. Therefore, if valid, these patents cover only those products (paroxetine hydrochloride) made according to the specified process, just as process patents cover products made according to the specified process. In contrast, product patents, such as listable drug substance and formulation patents, cover a product regardless of the process by which it is made. Thus, product-by-... 

Other types of drug-related patents include process, use, and formulation patents. Chemists are responsible for process patents, which describe an improved method of preparation of some drug substance but are minimally involved with the others. Use patents are based on the discovery of some unobvious utility of a compound that is either part of the public domain or covered by an existing patent such discoveries are most likely to be made by biologists. Formulation patents disclose a preferred means of drug delivery of a known drug substance. 

Needle-free drug delivery was first proposed as early as the mid-19th century and was demonstrated to work many decades ago with one of the first major patents filed by Lockhart in the 1930sJ At first glance, it is a concept both highly attractive and very simple— accelerate a drug formulation (liquid, powder, or depot) so that it penetrates the skin without the requirement for a needle. This avoids a multitude of disadvantages that are inherent in needle use ... 

Platz, R.M. Ip, A. Whitham, C.L. Process for Preparing Micronized Polypeptide Drugs. US patent 5,354,562, 1994. Platz, R.M. Utsumi, J Satoh, Y Naruse, N Pharmaceutical Aerosol Formulation of Solid Formulation of Solid Polypeptide Microparticles and Method for the Preparation Thereof. World IPO 9,116,038, 1991. 

Process patents (i.e., patents claiming processes for making a drug compound or formulation) are not listed by the FDA in connection with approved drug formulations. Thus, process patents are not subject to... 

As a newly identified drug progresses through chemical, pharmaceutical, and clinical development, it becomes the subject of more and more patents. They restrict themselves to newly invented chemical processes and drug formulations and to additional claims of methods of medical use. The drug would not have entered development if it were not already protected by a... 

Mueller B.W. and Fisher W. 1989. Manufacture of sterile sustained release drug formulations using liquefied gases. W. Germany Patent No. 3-744-329. 

At this very early stage, the possibility of using the lung to deliver systemic medication was considered possible. Other drug formulations intended for use in an MDI were also patented. These included both nicotine and insulin. Although insulin was shown in animal experiments to cause hypoglycemia, the effect was very variable and this initiative was not then pursued. It is of interest... 

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