Compositions are mixtures of materials rather than one single compound. Formulations are always compositions and raw materials are commonly compositions. Compositions are different from compounds in that the former is a single entity. For an explanation of the difference between a compound and a composition, read a former "Comparatively Speaking" column on the subject.
"Composition of matter" is a legal term used in US patent law that refers to one of the four types of things that can be patented. Additionally, processes, machines and articles of manufacture can be patented.
A newly synthesized chemical compound or molecule in addition to a formulation may be patented as a "composition of matter." The basis for patents is found in Article 1, Section 8, Cause 8 of the Constitution of the United States of America. The term "composition of matter" is found in the Patent Act of 1790.
The formulator is likely to encounter the use and misuse of these terms. The world of the formulator more and more intersects chemistry, formulation science, patent law and marketing. Terms often get misused and this causes misunderstanding. The formulator is likely to run into these terms, the first related to raw materials and the second in dealing with patents that are either compounds or formulations. The formulator should not use of the phrase "composition of matter" except as it relates to patent usage.