[emphasis added]

I am doing some research on a legal issue for a drug patent case.  There is a dispute between the parties of whether a "solvate" is necessarily "crystalline."

It is undisputed that the active ingredient of the drug combines with the solvent to form a complex, i.e., a "solvate.".  The dispute arises where one side insists that the solvate is necessarily crystallized, where as the other side says that when the complex is formed, the active ingredient may be "reacted from, precipitated, or crystallized."

Does this make sense to anyone? Just interested to see what people here have to say...

[discodermolide]

A solvate arises when solvent molecules are trapped within the lattice of the solid. The solvate can be crystalline or amorphous. It can be prepared by crystallising the compound from the desired solvent. It can form by precipitation from a solvent by adding an anti-solvent. I think reacted is going too far.
Usually the solvate can be dried to remove most of the solvent but sometimes some will remain as a solvent of crystallisation, examples are water, methanol, acetonitrile and so on.

[emphasis added]

A solvate arises when solvent molecules are trapped within the lattice of the solid. The solvate can be crystalline or amorphous. It can be prepared by crystallising the compound from the desired solvent. It can form by precipitation from a solvent by adding an anti-solvent. I think reacted is going too far.
Usually the solvate can be dried to remove most of the solvent but sometimes some will remain as a solvent of crystallisation, examples are water, methanol, acetonitrile and so on.

Wow, what a great answer.  Who needs expert witnesses haha.  If you wouldn't mind clarifying one thing further, what would you say is the difference between "amorphous" and "crystalline?"

[discodermolide]

A crystalline compound has a defined microstructure, an amorphous compound does not.
Perhaps Wiki can give you a better definition?
Compare salt and flour

[orgopete]

A solvate arises when solvent molecules are trapped within the lattice of the solid. The solvate can be crystalline or amorphous. It can be prepared by crystallising the compound from the desired solvent. It can form by precipitation from a solvent by adding an anti-solvent. I think reacted is going too far.
Usually the solvate can be dried to remove most of the solvent but sometimes some will remain as a solvent of crystallisation, examples are water, methanol, acetonitrile and so on.

I had to look this up to be sure that my intuition about solvate was correct. Wiktionary lists a solvate as "A complex formed by the attachment of solvent molecules to that of a solute." That is what I thought it meant. In that sense, a solvate becomes a compound with properties different than the non-solvated compound. In my experience, a solvent cannot be removed from the crystal by drying under vacuum with heat. They can if sufficient heat is applied to destroy the crystal.

I am inclined to think that a solvate is crystalline and thus can be distinguished from a something without definite form and composition as may occur with an amorphous solid. If water is added to sugar, you can get a syrup. Some of the water present may be attached to the sugar, but I don't consider this a solvate. It is simply a mixture of sugar and water without a defined molecular ratio. Sodium sulfate forms several different solvates or hydrates. Each is a separate compound.

It sounds as if the "crystalline" party is infringing upon a broader composition of matter in which the claim is to derivatives of the original. I'd prefer to represent the broader composition of matter client (unless you can establish some non-obviousness claim).

[AWK]

Compare salt and flour

Flour is not a good example in this case. Term amorphous concerns a pure substance, not a mixture.

[discodermolide]

Compare salt and flour

Flour is not a good example in this case. Term amorphous concerns a pure substance, not a mixture.

This was meant to convey the texture not the composition.

[PhDoc]

Before presuming the experts are worthless to you, please realize one thing. An amorphous solvate is a nightmare in disguise. So long as the trapped solvent is innocuous, there's no need to worry. What is cause for concern, however, is a change in crystalline structure upon standing or exposure to a certain temperature for prolonged conditions.

Any experienced drug development chemist will tell you that polymorphs can lead to trouble. If you manage to go to clinical trials with a polymorph, making it into Phase III, then have a batch of Phase III material become crystalline.... then my friend, you're screwed, and so is you clinical study, and so is your company. Why? Because you haven't characterized the crystalline form of the drug.

I designed drugs for 15 years (placed three into clinical trials) and I've seen this happen on more than one occasion. If there is any way to make a salt of your compound so the solvent is eliminated, I'd suggest going that route. If not, I'd suggest investing time into finding an energetically stable crystalline form to prevent the scenario I've just described.

What would be quite interesting is to see if a competing company can take your IP, develop a crystalline entity, and then patent the use of that particular crystal form. I've never heard of this happening, however there's always a first time for everything.

One more thing. If a competing company makes a prodrug of your compound and proves use of the prodrug is superior to delivery of the active form, you may also have something to worry about. You can claim prodrugs in your broad scope, however, unless you make the prodrugs you claim, I'd hate to be the one who has to argue the case in court.

A patent is not a patent until challenged in court. Until then, it's merely an approved application.

Good luck!