Solubility question

[Sho'Nuff]

As many of you know, I am a patent attorney. I'm reviewing a patent for a client, and am trying to determine the meaning of a particular phase used in the claims of that patent. Without giving too much away, the phrase reads essentially as follows:

"a method of increasing the solubility of XYZ solid, by providing the XYZ solid to a solution of component A in solvent B."

Looks simple enough, right? But the issue I am struggling with is whether the phrase "increases the solubility of XYZ solid" actually means anything.

To address this issue, I'd like some input on the following (potentially stupid) question. and that question is as follows:

"Is it possible to increase the solubility of a solid in a liquid, without changing the composition, temperature or another aspect of that liquid?"

Put another way, "Am I correct in understanding that solubility of a solid in a given solution is inherent to the solid itself, and cannot be altered without changing some aspect of the solid and/or the liquid?"

 

[CycloWizard]

The answer to your first question is, of course, no. The solubility is a function of intermolecular interactions (i.e. interactions between solute and solvent molecules), and therefore depends on composition, temperature, and pressure. The original claim you quoted indicates that they changed the solubility of XYZ by adding an additional component to the solvent. I think I see what you mean - that they did not alter the solubility of XYZ itself. However, it may be possible to alter the solubility of XYZ in solvent B by adding component A to solvent B. Since you're an attorney, I assume you're focusing on the way it's phrased, which is imprecise. However, I think the meaning is fairly clear (though it should obviously be amended in the final patent).

 

[Sho'Nuff]

The answer to your first question is, of course, no. The solubility is a function of intermolecular interactions (i.e. interactions between solute and solvent molecules), and therefore depends on composition, temperature, and pressure. The original claim you quoted indicates that they changed the solubility of XYZ by adding an additional component to the solvent. I think I see what you mean - that they did not alter the solubility of XYZ itself. However, it may be possible to alter the solubility of XYZ in solvent B by adding component A to solvent B. Since you're an attorney, I assume you're focusing on the way it's phrased, which is imprecise. However, I think the meaning is fairly clear (though it should obviously be amended in the final patent).

Agreed. Now let me tweak the situation a little bit and get your thoughts.

Say that instead of reciting:

"a method of increasing the solubility of a solid XYZ, by providing the solid XYZto a solution of component A in solvent B." the claim read:

"a method of increasing the solubility of a solid XYZ, by providing a XYZ to a solution of component A in solvent B" where XYZ is a generic class of chemical compounds, e.g., amides.

In my opinion, the claim language in the second case is horribly unclear. In fact, it is so unclear that unless "providing a XZY" is interpreted as "providing the (or a) XYZ solid," the claim has no meaning. Why? Because if XYZ were a liquid, its addition to a solution of component A in solvent B would not "increase the solubility of a XYZ solid." Rather, it would increase the solubility of the XYZ liquid. Right? Or would you interpret the latter claim as requiring "the XYZ solid" and "a XYZ" to be different compounds?

 

[CycloWizard]

Agreed. Now let me tweak the situation a little bit and get your thoughts.

Say that instead of reciting:

"a method of increasing the solubility of a solid XYZ, by providing the solid XYZto a solution of component A in solvent B." the claim read:

"a method of increasing the solubility of a solid XYZ, by providing a XYZ to a solution of component A in solvent B" where XYZ is a generic class of chemical compounds, e.g., amides.

In my opinion, the claim language in the second case is horribly unclear. In fact, it is so unclear that unless "providing a XZY" is interpreted as "providing the (or a) XYZ solid," the claim has no meaning. Why? Because if XYZ were a liquid, its addition to a solution of component A in solvent B would not "increase the solubility of a XYZ solid." Rather, it would increase the solubility of the XYZ liquid. Right? Or would you interpret the latter claim as requiring "the XYZ solid" and "a XYZ" to be different compounds?

Yeah, I more or less agree. If it were me, I would write:
"a method of increasing the solubility of solid XYZ in solution B by the addition of additional component A"
There are some circumstances where this would also be incorrect (i.e. if XYZ were insoluble in B and caused A to precipitate on addition). Because of this case, the best way to write it is probably:
"a method of increasing the solubility of solid XYZ in solution B by introducing solid XYZ to a solution of B containing additional component A."
I'm not sure if you're writing or evaluating the application, so this may or may not be helpful...

 

[shortylickens]

By a fantastic coincidence, I am doing solubility in chemistry right now.
But it looks like everyone else already covered it, so I wont bother.

 

[GWestphal]

Often times certain drugs are soluble in some solvent, but only in a certain pH range. A drug I work with is only soluble in water if the pH is above 9. Chemicals to alter pH (HCl, NaOH etc) are generally not considered the "solvent" in that situation. I'm guessing he probably meant something like that.

 

[sao123]

A common simple plain language example of the above:

Generally there are 3 different types of compounds... ionic(salts), polar(water), nonpolar(oils)

the general rule is: like dissolves like. Unlikes do not dissolve each other.

Oils will not dissolve in water:

However, there are certain hybrid structures, one such is "sodium stearate" or "sodium palmitate" (common ingredients in household soaps), which have properties of two structures.
Half of the molecule is polar, and half non-polar.

What happens is, the polar half will dissolve in the polar solvent, and the nonpolar in the nonpolar solvent: or put short:


Soap dissolves in water, and oil dissolves in soap, allowing oil to dissolve in water.

 

[Sho'Nuff]

Yeah, I more or less agree. If it were me, I would write:
"a method of increasing the solubility of solid XYZ in solution B by the addition of additional component A"
There are some circumstances where this would also be incorrect (i.e. if XYZ were insoluble in B and caused A to precipitate on addition). Because of this case, the best way to write it is probably:
"a method of increasing the solubility of solid XYZ in solution B by introducing solid XYZ to a solution of B containing additional component A."
I'm not sure if you're writing or evaluating the application, so this may or may not be helpful...

I'm reviewing it as part of a freedom to operate analysis I am performing for a client. Depending on how the claim in question is interpreted, it could be problematic or not a problem at all.

If I were drafting the claim, I probably would have used the same language you suggest, i.e., "a method of increasing the solubility of solid XYZ in solution B by introducing solid XYZ to a solution of B containing additional component A." But unfortunately, the drafter of the patent in question didn't do that. He omitted the "solid" before the second recitation of XYZ, and that is causing all sorts of claim interpretation issues. It never ceases to amaze me how one word can make a world of difference in IP law.

 

[CycloWizard]

I'm reviewing it as part of a freedom to operate analysis I am performing for a client. Depending on how the claim in question is interpreted, it could be problematic or not a problem at all.

If I were drafting the claim, I probably would have used the same language you suggest, i.e., "a method of increasing the solubility of solid XYZ in solution B by introducing solid XYZ to a solution of B containing additional component A." But unfortunately, the drafter of the patent in question didn't do that. He omitted the "solid" before the second recitation of XYZ, and that is causing all sorts of claim interpretation issues. It never ceases to amaze me how one word can make a world of difference in IP law.

In that case, I'm not a lawyer, but in terms of the physical reality of the situation, the claim just doesn't make sense as written when strictly interpreted. I can see what was trying to be said, but that's not actually what was written. I assume the latter is more important in this case.

 

[Turtle.Man]

My interpretation of the claiim is that the author has invented an additive (component A) that facilitates the solubility of XYZ in solvent B. It will enable the preparation of solutions of XYZ that are of higher concentration than was previously possible. You'll have to do the "legalese" translation yourself, though.

Edit: BTW, XYZ doesn't necessarily have to be a solid. Component A could also increase the solubility of a liquid "XYZ" in solvent B.

 

[Turtle.Man]

but in terms of the physical reality of the situation, the claim just doesn't make sense as written when strictly interpreted. I can see what was trying to be said, but that's not actually what was written. I assume the latter is more important in this case.

Yep, it's a legal document, all right!

 

[Paperdoc]

I'm jumping in as a chemist with some familiarity with intellectual property. First, "solution" is NOT restricted to adding a solid to a liquid to achieve a liquid-only mixture. "Solution" can refer to a solid in a liquid (table salt in water), to a liquid in another liquid (ethyl alcohol in water), to a gas in a liquid (oxygen in water, necessary for all aquatic life forms), to a solid in a solid (metal alloys), to gases in a gas (our air, with oxygen, carbon dioxide and many small components in nitrogen) etc. Technically, colloidal suspensions are not "solutions". These latter include things like oil/water mixtures facilitated by detergents that help to stabilize very small oil droplets in water, whipped cream (air colloidally dispersed as microscopic bubbles in cream), homogenized milk, gravy and lots of things. BUT many people think of colloidal suspensions as solutions because they look like "normal" liquids that are not separated into two obviously different layers, you can see through some of them, they flow smoothly and remain uniform,etc. So I'm not sure whether OP really is dealing with a solution or with a colloidal dispersion being enhanced by a surfactant additive.

So, in a sense, the original language that specifies that the invention works for "XYZ solid" may be limiting the scope of the claim unnecessarily. This becomes even more of a consideration if the claim is expanded to include several members of a class of solutes (OP suggested amides as an example) which may exist as two or more physical forms at room temperature. Or, expanding our view in a different direction, the invention may perform well for enhancing a solution of solid XYZ in solute B at room temperature, but may ALSO perform the same function at a higher temperature when the pure XYZ might be a liquid; the specification of "XYZ solid" does not include this possibility.

From a chemist's perspective, a solution of XYZ in B with no other components present is called a binary solution, and there is a solubility limit associated with this mixture, affected by temperature, pressure, etc. When you change the system to add a third component (A), the mixture becomes a ternary solution, and the solubility limit for the original binary solution no longer is valid. In the new ternary system the solubility limit may be higher or lower than the original system's. As a chemist, I would say you did not increase the solubility of XYZ in B; instead, you changed to a new solvent system able to dissolve a larger proportion of XYZ. However, in Patent language the common use of those terms may not be quite what a semi-pedantic chemist might say.

 

[Sho'Nuff]

As a chemist, I would say you did not increase the solubility of XYZ in B; instead, you changed to a new solvent system able to dissolve a larger proportion of XYZ. However, in Patent language the common use of those terms may not be quite what a semi-pedantic chemist might say.

Actually, the meaning that a "person of ordianry skill in the art" would attribute to claim language is quite important in U.S. patent law. Generally, claim interpretation proeceds as follows:

1. What do the terms of the claim "literally" mean?

2. If the meaning deduced by #1 is unclear, what does the specification have to say (I.e., claims are interpreted "in light of" the specification)?

3. If the specification is silent or still does not render the meaning of the claim language clear, how would one of ordinary skill in the art interpret the claim?

4. If the claim is STILL unclear after the court attempts to interpret it via method 1, 2 and 3, then the claim is likely invalid for failing to comply with 35 U.S.C. 112(2), which requires a patent application conclude with "one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention."

 

[Paperdoc]

I agree that my "nit-picking" way of phrasing probably is not what a patent legal expert or court would say. Indeed, if one phrases it as "increases the solubility of XYZ....", as you originally outlined, almost everyone with some knowledge of the art would understand perfectly the meaning. And that is the point - although the technical language and concepts in this case are drawn from physical chemistry, the courts are not rigidly limited to that particular use of the words. Communicating the core ideas is the priority.