Obviousness

Based on the provided prior art, an analysis of the obviousness of the claims of U.S. Patent 12,290,598 under 35 U.S.C. § 103 indicates a strong likelihood that the key claims would be considered obvious to a person having ordinary skill in the art (POSITA) at the time of the invention.

Obviousness of Claim 1 (Orally Disintegrating Tablet Composition)

Claim 1 is directed to an orally disintegrating tablet (ODT) comprising corticosteroid-containing granules and rapidly dispersing microgranules. The specific limitations involve the composition of these microgranules, which are made from a disintegrant and a sugar alcohol/saccharide with defined particle sizes.

Combination of Prior Art:

1. Primary Reference: U.S. Patent No. 8,771,729 (the parent patent in the '598 family).
2. Secondary Reference: U.S. Patent Application Publication No. US 2005/0232988.

Analysis:
The '729 patent discloses the core inventive concept: an ODT containing a corticosteroid (such as fluticasone or budesonide) for the topical treatment of inflammatory gastrointestinal conditions like eosinophilic esophagitis (EoE). This reference establishes the desirability of creating a fast-disintegrating solid dosage form that, upon administration, forms a suspension of the corticosteroid to coat the esophagus.

However, the '729 patent does not specify the exact method for achieving the rapid disintegration in the manner claimed in the '598 patent. This is where US 2005/0232988 becomes relevant. This application explicitly teaches the creation of an ODT platform technology based on "rapidly dispersing microgranules" composed of a disintegrant (like crospovidone) and a sugar alcohol (like mannitol). The '598 patent text itself explicitly refers to the method of US 2005/0232988 for preparing its own microgranules.

Motivation to Combine:
A person of ordinary skill in the art, such as a pharmaceutical formulator, tasked with developing the corticosteroid ODT described in the '729 patent would seek a suitable ODT manufacturing platform. The goal would be to create a tablet that not only disintegrates quickly but also produces a smooth, palatable, and easily swallowable suspension to ensure the corticosteroid effectively coats the inflamed esophageal tissue. US 2005/0232988 provides a direct and well-documented solution to this exact formulation challenge. A POSITA would have been motivated to use the platform taught in US 2005/0232988 to formulate the corticosteroid ODT taught in the '729 patent to achieve the desired properties of rapid disintegration and good mouthfeel. The combination would have been a predictable and straightforward application of a known ODT platform to a known therapeutic concept.

Obviousness of Claim 15 (Method of Making the ODT)

Claim 15 protects the method of manufacturing the ODT, with a key step being the use of an external lubrication system during tablet compression.

Combination of Prior Art:

1. Primary Reference: The combination of U.S. Patent No. 8,771,729 and US 2005/0232988.
2. Secondary Reference: General knowledge in the art of pharmaceutical tablet manufacturing.

Analysis:
The combination of the '729 patent and US 2005/0232988 teaches the composition of the tablet to be made. The question is whether the specific manufacturing method, particularly the use of an external lubrication system, would have been obvious.

The use of external lubrication systems on rotary tablet presses was a well-established and conventional technique in the pharmaceutical industry long before the patent's priority date. ODT formulations are known to be particularly challenging to compress, as they must be hard enough to withstand packaging and handling yet soft enough to disintegrate rapidly. Internal lubricants (like magnesium stearate blended into the powder) can sometimes impede water absorption and slow disintegration.

Motivation to Combine:
A POSITA responsible for compressing the ODT formulation of Claim 1 would have been aware of the potential manufacturing issues, such as sticking to punches and dies, and the negative impact of internal lubricants on disintegration time. To solve these known problems, it would have been an obvious and conventional choice to employ an external lubrication system. This approach allows for efficient tablet production while minimizing the amount of lubricant in the final tablet, thereby preserving the rapid disintegration characteristics essential for the product's function. The motivation is simply to apply a standard, known-to-work manufacturing technique to overcome predictable challenges in producing a specific type of tablet.

Obviousness of Claim 20 (Liquid Pharmaceutical Composition)

Claim 20 is directed to a substantially non-aqueous liquid composition containing a corticosteroid and a "bio-gelling polymer" that increases viscosity upon contact with the gastrointestinal tract.

Combination of Prior Art:

1. Primary Reference: The background disclosure of the '598 patent itself (and its family, e.g., the '729 patent), which describes the clinical need and prior "off-label" practices.
2. Secondary Reference: General knowledge in the art regarding mucoadhesive and in-situ gelling drug delivery systems.

Analysis:
The specification of the '598 patent establishes the problem to be solved: existing liquid corticosteroid treatments for EoE, such as mixing nebulizer solutions with sugar to create a slurry, are suboptimal because they are quickly washed away from the esophagus. The goal is to increase the residence time of the corticosteroid on the inflamed tissue.

The use of bio-gelling polymers (including thermosensitive, pH-sensitive, or water-activated polymers) was a well-known strategy in the pharmaceutical arts for achieving prolonged topical drug delivery. Numerous cellulose derivatives, polyacrylates (carbomers), poloxamers, and other polymers were known to form gels in-situ, increasing viscosity and adhering to mucosal surfaces.

Motivation to Combine:
A POSITA, faced with the problem of improving the esophageal residence time of a liquid corticosteroid, would have been motivated to find a way to make the formulation thicker and more adhesive after administration. The most direct and obvious way to achieve this would be to incorporate a known bio-gelling or mucoadhesive polymer into the formulation. A formulator would have reasonably expected that adding a known bio-gelling polymer to a liquid corticosteroid would result in a composition that gels upon contact with saliva and the moisture of the GI tract, thereby prolonging the topical contact of the drug with the esophagus. This represents the application of a known drug delivery technology to solve a clearly identified problem, with a high degree of predictability of success.