This invention relates to methods and apparatuses for transferring and manipulating solids for the purpose of automating PXRD (powder X-ray diffraction), Raman spectroscopy, or other compatible methods of analysis. Specific embodiments of the invention are particularly suited for the automated transfer and analysis of small quantities of solid particles.
Structure plays an important role in determining the properties of substances. The properties of many compounds can be modified by structural changes, for example, different polymorphs of the same pharmaceutical compound can have different therapeutic activities. Understanding structure-property relationships is crucial in efforts to maximize the desirable properties of substances, such as, but not limited to, the therapeutic effectiveness of a pharmaceutical.
This invention relates generally to systems and methods for rapidly determining the characteristics of an array of diverse materials, and to systems and methods for rapidly determining the characteristics of a library of diverse materials using electromagnetic radiation.
In a first embodiment, the present invention provides a method for the analysis of a solid material, comprising:
In another embodiment, the present invention provides a method for the analysis of a plurality of solid samples, comprising:
In another embodiment, the present invention provides a system for analyzing a solid material, comprising:
In another embodiment, the present invention provides a system for analyzing a plurality of solid samples, comprising:
FIG. 1—Illustrates a coring tool with a narrow region;
FIG. 2—Illustrates a coring tool with a bent rod;
FIG. 3—Illustrates an apparatus used to set cavity depth of coring tools;
FIG. 4—Illustrates loading a coring tool with solid material;
FIG. 5—Illustrates a coring tool after solid material is captured;
FIGS. 6A-6D—Illustrates various tapers for coring tips;
FIG. 7—Illustrates compression of a sample plug;
FIG. 8—Illustrates extrusion of a sample plug;
FIG. 9—Illustrates a coring tool rack;
FIG. 10—Illustrates a coring tool rack with lifting plate in raised position;
FIG. 11—Illustrates a coring tool rack with lifting plate in lowered position;
FIG. 12—Illustrates a pin bed for removal of coring rods;
FIG. 13—Illustrates important dimensions for sample analysis;
FIG. 14—Illustrates an unoptimized plate for sample analysis;
FIG. 15—Illustrates a plate with 2 holes per diagonal;
FIG. 16—Illustrates a plate with 3 holes per diagonal;
FIG. 17—Illustrates a plate with 4 holes per diagonal;
FIG. 18—Illustrates a plate with 8 holes per diagonal;
FIG. 19—Illustrates a plate for applications where the incident beam length is less than 10.00 mm;
FIG. 20—Illustrates a plate for applications with a maximum beam intensity.
The present invention encompasses methods and apparatuses for picking up, compressing, and precisely positioning small samples of material (e.g. amounts of less than about 5.00 mg), for the purpose of automating PXRD (Powder X-ray Diffraction), Raman Spectroscopy, or other compatible methods of analysis. Sample quantities can be, for example, less than about 5.00 mg, 2.5.00 mg, 1.00 mg, 750.00 micrograms, 500.00 micrograms, 250.00 micrograms, 100.00 micrograms, 50.00 micrograms, 25.00 micrograms, 10.00 micrograms, 5.00 micrograms, or 1.00 microgram of solid particles. Particular embodiments of the present invention involve coring a sample plug of powder from the bottom or sides of a vial using a coring tool that comprises a hollow needle with a slideable close fitting rod contained inside the hollow needle. See, Published Application No. US20040146434, filed Nov. 3, 2003, and International Publication No. WO04/042327, filed Nov. 3, 2003, the contents of which are incorporated by reference in their entireties. To provide optimal signal quality, a sample plug contained inside the needle tip can be compressed by the rod and extruded above the needle tip a small distance (e.g., about 0.10 mm to 1.00 mm) to allow optimal exposure to a beam of electromagnetic radiation. Each coring tool is, optionally, placed in a coring tool rack, which is defined as a substrate that precisely positions the sample plugs in x, y, and z coordinates relative to the rack base. The samples(s) is/are then placed on a cradle in a machine, such as a surface PXRD, that emits an electromagnetic beam of radiation which is directed through each sample plug to obtain information about the crystalline structure of each sample plug.
This method has several advantages over other methods known in the prior art. For example, a system described in the art involves forming crystals on a substrate that is used for PXRD and Raman spectroscopic analysis (See U.S. Pat. Nos. 6,371,640 and 6,605,473). The present invention has the following advantages over such a system for both PXRD and Raman Spectroscopy: 1) The coring tool of the present method serves to both mill and compress powder crystals prior to analysis, thus improving signal quality; 2) The coring tool of the present method also requires a smaller amount of sample for quantitative analysis; 3) The present method allows the heights of sample plugs to be adjusted so they are coplanar. This allows the angle of incidence of the X-ray beam to be closer to horizontal, thus improving signal quality without picking up signals from neighboring sample plugs; 4) The present invention leaves material behind that is not exposed to x-ray radiation and, hence, decreases the existence of radiation-damaged material; and 5) The present invention can be used to extract sample material prepared in sealable individual vials, which provide superior flexibility and protection of crystalline samples from the environment.
As used herein, the term “processing parameters” means the physical or chemical conditions under which a sample is subjected and the time during which the sample is subjected to such conditions. Processing parameters include, but are not limited to, adjusting the temperature; adjusting the time; adjusting the pH; adjusting the amount or the concentration of the sample; adjusting the amount or the concentration of a component; component identity (adding one or more additional components); adjusting the solvent removal rate; introducing a nucleation event; introducing a precipitation event; controlling evaporation of the solvent (e.g., adjusting a value of pressure or adjusting the evaporative surface area); and adjusting the solvent composition. Solid samples can be subjected to a diverse range of processing conditions before analysis is completed. The present invention provides the capacity to alter processing conditions from one sample to the next, or from one array of samples to the next, or from one sub-array of samples to the next. The isolation of each sample facilitates a more accurate analysis of solid material and is significantly less prone to contamination than other methods (e.g., plate-based methods).
Sub-arrays or even individual samples within an array can be subjected to processing parameters that are different from the processing parameters to which other sub-arrays or samples, within the same array, are subjected. Processing parameters can differ between sub-arrays or samples when they are intentionally varied to induce a measurable change in the sample's properties. Thus, according to the invention, minor variations, such as those introduced by slight adjustment errors, are not considered intentionally varied.
Embodiments of the invention are particularly suited for the automated or high-throughput analysis of solids such as, but not limited to, pharmaceuticals, excipients, dietary substances, alternative medicines, nutraceuticals, agrochemicals, sensory compounds, the active components of industrial formulations, and the active components of consumer formulations. Solids analyzed using the methods and devices of the invention can be amorphous, crystalline, or mixtures thereof.
In a first embodiment, the present invention provides a method for the analysis of a solid material, comprising:
In a specific embodiment of the present invention, the analysis comprises x-ray scattering. In another embodiment, the analysis comprises Raman scattering.
In another embodiment, the method further comprises compressing the solid material after the plug is formed.
In another embodiment, the method further comprises loading the coring tool onto a rack after the solid material is extruded.
A specific method of this embodiment comprises the steps of: (a) coring the solid material with a coring tool which comprises a narrow region in the needle of said coring tool or a bent rod inserted in the needle of said coring tool, such that a plug is formed; (b) compressing the plug of solid material with a mallet and a pin; (c) extruding the plug of compressed solid material with a pin; (d) loading the coring tool onto a rack; (e) exposing the compressed solid material to radiation; and (f) detecting scattered radiation.
In another embodiment, the position of a pin in step (b) is adjusted by a micrometer.
In another embodiment, the rack in step (d) comprises a top plate with one or more holes, and optionally, side walls and a bottom plate. Each hole in the top plate has a diameter which is about 10.00 micrometers, 20.00 micrometers, 30.00 micrometers, 40.00 micrometers, 50.00 micrometers, 60.00 micrometers, 70.00 micrometers, 80.00 micrometers, 90.00 micrometers, 100.00 micrometers, 150.00 micrometers, 200.00 micrometers, or 250.00 micrometers or more, greater than the diameter of the coring tool. In another embodiment, the rack comprises a top plate which is optionally made of polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), or another material that absorbs X-ray radiation (or infrared or other radiation). In another embodiment, the rack comprises a plurality of holes.
In another embodiment, the rack in step (d) optionally comprises a lifting plate. The lifting plate optionally comprises one or more holes corresponding to the holes in the top plate. Optionally, the lifting plate can be locked into place via thumbscrews or another device. Stops may be used to define a maximum height, a minimum height, or an intermediate height of the lifting plate. The bottom plate of the rack optionally comprises one or more set screws for leveling, raising, or lowering the lifting plate.
In another embodiment, the rack in step (d) optionally further comprises a pin bed for removing one or more rods from the needle(s) of the coring tool(s). Optionally, the needles are held in place by a retainer plate. The retainer plate rests on walls (legs) which facilitate removal of coring tool rods. Alignment and stabilization of the retainer plate can optionally be performed by screws, pins, or other means.
In another embodiment, an x-ray probe emits radiation in a beam with a beam length less than or equal to about 50.00 mm, 40.00 mm, 30.00 mm, 20.00 mm, 10.00 mm, or 5.00 mm. The beam length is defined as the distance between the x-ray probe emission aperture and the solid material loaded onto the coring tool (See item 98 of
In another embodiment, the present invention provides a method for the analysis of a plurality of solid samples, comprising:
In another embodiment, the present invention provides a system for analyzing a solid material, comprising:
In another embodiment, the present invention provides a system for analyzing a plurality of solid samples, comprising:
Certain embodiments of the invention, as well as certain novel and unexpected advantages of the invention, are illustrated by the following non-limiting examples.
The first step of the present coring method involves setting the height of a coring cavity in needle 2.
Next, sample plug 23 can be compressed and extruded, as illustrated in
Next, coring tools can be loaded into coring tool rack 39 shown in
Given the number of holes per diagonal in a column, represented by nd, the number of holes per row ny, the array width Wa, and X hole spacing 1 s1x, the Y hole spacing sy and minimum hole distance s can be computed via equation (1) and equation (2), respectively.
Given 8 holes per column (nx=8), the resulting X hole spacing 2 S2x can be computed given the number of holes per diagonal nd, the array length La, and X hole spacing 1 s1x, according to Table 2.
Table 3 shows computed values for s, sy and S2x, given some example values for the input variables in Equation (1), Equation (2), and the equations in Table 2.
As an example which includes realistic constraints, given a beam width of 1.00 mm and a width tolerance of 0.40 mm, sy should be 1.40 mm or larger. As stated earlier, given a beam incident angle of 2 degrees, s2x should be greater than 18.00 mm to tolerate a 0.50 mm plug height difference. Lastly, it is desirable for array length La to be 50.00 mm or less to minimize beam travel. As can be seen in Table 3, the nd=4 embodiment in
If the beam width used was 0.60 mm instead of 1.00 mm, then an sy value of 1.00 mm could be tolerated, and the nd=8 embodiment in
For applications where the incident beam length used is less than 10.00 mm, the hole pattern shown on top plate 210 in
Having now fully described this invention, it will be understood by those of ordinary skill in the art that the same can be performed within a wide and equivalent range of conditions and other parameters without affecting the scope of the invention or any embodiment thereof For example, functional aspects of the present invention such as, but not limited to, thumbscrews, pins, and screws may also be satisfied using alternative means and, therefore, are included in the present invention. All patents and publications cited herein are fully incorporated by reference in their entireties.
The present application claims the benefit of priority of U.S. Provisional Application Ser. No. 60/562,358, filed Apr. 15, 2004, which is hereby incorporated by reference herein in its entirety, including any figures, tables or drawings.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US05/12686 | 4/14/2005 | WO | 00 | 10/20/2008 |
Number | Date | Country | |
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60562358 | Apr 2004 | US |