The claims of each patent in the Orange Book have been examined, and we have provided our opinion of the category that a claim should fall into. As we went through the patents, we kept adding new categories, finally arriving at the following nineteen:
 

Claim Type	Explanation
Compound	Just the chemical, usually delineated by its structure
Composition	One or more active ingredients and a pharmaceutically acceptable carrier
Formulation	Any combination of one or more active ingredients where something in addition to the presence of the active ingredients and the carrier is specified. This can be a specific excipient, or it can be the ratio of two active ingredients, or it can be any other claim limitation that we feel distinguishes the claim from a composition claim.
Impurity content limitation	Compound-ish claim that recites a compound and an impurity. The maximum level of the impurity is usually a limitation.
Method of use	A method of using the active ingredient to treat a disease
Process	Method of making something. E.g., method of making the active ingredient; method of making a dosage form; method of preparing a formulation.
Product-by-process	Anything where a product (including an intermediate or excipient) is described by its method of preparation
Device	Anything with “parts,” e.g., walls, chambers, etc., such as an osmotic pump dosage form. It of course also includes more traditional devices, such as spray pumps, syringes, etc.
Device part	An individual part of a device, e.g., a dosage counter for an asthma inhaler, a rubber tip for a syringe plunger.
Kit	Mainly defined in the claim, itself, e.g., “a kit comprising . . .”
Intermediate	A chemical used to make another chemical. DNA is an intermediate when the final product is a protein or polypeptide.
Method of administration	A way of getting the drug into the patient
Excipient	An inactive part of a dosage form
Packaging or device material	Material from which the packaging or device is constructed
Diagnostic or surgical method	Self-explanatory
Method of improving a formulation	E.g., “a method of improving the stability of formulations containing compound X.”
Drug in a container	E.g., “an article of manufacture comprising drug X in a container”
New polymorph, salt or hydrate	A new form of a previously approved compound
Method of improving a treatment	E.g., “a method of reducing the side effects due to the administration of drug X”
Functional tablet design	Tablets that are easy to break into equal-size pieces
Ornamental appearance of a device	A design patent