DETAILED ACTION
The amendment and RCE filed on 05/22/2026 has been entered and fully considered. Claim 17 is canceled. Claims 1, 5-16 and 18 are pending, of which claims 1 and 18 are amended.
Response to Amendment
In response to amendment, the examiner maintains rejection over the prior art established in the previous Office action.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1, 5-16 and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (CN 110862305, IDS) (Li).
Regarding claim 1, Li teaches a method for detecting content and fingerprint of monosaccharide in a sample of carob water extract (par [0065]), comprising:
performing detection by using a high-performance liquid chromatography-evaporative light scattering detection method (par [0061]),
wherein the monosaccharide comprises D-glucose anhydrous, D-fructose, sucrose, and pinitol (Fig. 4, par [0067]),
wherein the chromatographic column in the high-performance liquid chromatography-evaporative light scattering detection method is a ZORBAX Carbohydrate column with a specification of 4.6 mm x 250 mm and 5 μm (par [0061]),
wherein the mobile phase in the high-performance liquid chromatography-evaporative light scattering detection method is a gradient solution of acetonitrile and water (par [0061]-[0063]),
wherein a flow rate of the mobile phase in the high-performance liquid chromatography-evaporative light scattering detection method is 0.95-1.05 ml/min, preferably 1 ml/min (par [0061]).
Li does not specifically teach that the sample is Compound Kushen Injection CKI). However, Li discloses a high-performance liquid chromatography–evaporative light scattering detection (HPLC-ELSD) method for detecting monosaccharides including D-pinitol, fructose, glucose, and sucrose. The presently claimed method likewise uses HPLC-ELSD to detect the same types of monosaccharides. The difference between analyzing carob extract and analyzing CKI represents only a difference in the sample source, not a difference in the analytical principle.
A person of ordinary skill in the art would understand that HPLC-ELSD methods for carbohydrate analysis are broadly applicable to various plant-derived matrices and pharmaceutical preparations containing sugars. Applying the known analytical method of Li to another plant-derived or botanical composition containing the same analytes constitutes a predictable use of prior art elements according to their established functions, consistent with KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007).
Accordingly, the substitution of CKI for the plant extract analyzed in Li would have been obvious to a person of ordinary skill in the art seeking to analyze monosaccharides in another botanical preparation.
Both Prevail Carbo-hydrate ES column recited in the instant claim and ZORBAX Carbohydrate column used by Li are carbohydrate HPLC columns, 4.6 × 250 mm, 5 μm, designed for separation of simple sugars (glucose, fructose, sucrose, pinitol), commonly used interchangeably in ELSD sugar methods. The only difference is the commercial manufacturer (Prevail in the claim versus the column used by Li). Substituting one commercially available carbohydrate column for another of the same dimensions and particle size would have been an obvious design choice because such columns are widely recognized as interchangeable tools for carbohydrate separations.
Similarly, Li already teaches the use of acetonitrile–water gradient elution for separating the relevant sugars. The particular gradient profile recited in the claims represents a routine adjustment of gradient conditions during method development in chromatography. Adjusting gradient composition and timing to achieve desired retention times or resolution is a well-known practice in HPLC method optimization.
Therefore, the claimed column and gradient conditions represent routine analytical parameter selections, not a patentably distinct invention.
Column temperature in HPLC is a well-known variable affecting:
retention time
peak shape
chromatographic resolution
Accordingly, a person of ordinary skill in the art would routinely adjust column temperature to optimize chromatographic separation for a particular sample matrix.
Li already teaches performing HPLC analysis at 35 °C. Adjusting the temperature upward or downward within commonly used chromatographic ranges—including lower temperatures—would have been an obvious matter of routine experimentation to improve resolution between analytes.
It is well known in the art of ELSD sugar analysis that the drift tube temperature is adjusted empirically to achieve complete evaporation of solvent, adequate droplet drying, minimal thermal degradation and stable baseline.
Because Li already teaches the same sugars (pinitol, fructose, glucose, sucrose) and the same detection technique (HPLC-ELSD), one of ordinary skill in the art would have recognized that the drift tube temperature may be increased or decreased, the precise value depends on column conditions, solvent ratio, flow rate, and desired sensitivity. ELSD drift-tube temperatures in the sugar-detection literature commonly range from 40–80 °C, depending on aqueous mobile-phase proportion
Therefore, moving from Li’s 41 °C to applicant’s claimed 59–61 °C constitutes merely routine parameter optimization, without any unexpected results, yielding predictable performance improvements (e.g., better solvent removal under higher aqueous ratio).
Thus, it would have been obvious to one of ordinary skill in the art to optimize the evaporation temperature of the evaporation light detector in the high-performance liquid chromatography-evaporative light scattering detection by routine experimentation.
Nitrogen is the most common carrier gas used in ELSD. Thus, a PHOSITA would inherently choose nitrogen in the absence of any contrary teaching. Li’s ELSD settings assume a standard ELSD configuration; thus, nitrogen is the expected gas.
ELSD gas flow rate is a routine, result-effective parameter. Gas flow rate in ELSD affects aerosol droplet size, nebulization efficiency, signal strength, baseline noise. Thus, it would have been obvious to one of ordinary skill in the art to optimize the flow rate by routine experimentation.
With respect to the standard fingerprint comprising three unknown peaks, a D-fructose chromatographic peak, a pinitol chromatographic peak, a D-glucose anhydrous chromatographic peak, and a sucrose chromatographic peak, Li teaches chromatograms containing the known peaks for pinitol, fructose, glucose, and sucrose. The presence of additional unknown peaks is an expected result when analyzing a complex plant-derived sample matrix by HPLC-ELSD. Therefore, including unknown peaks together with known saccharide peaks in a chromatographic fingerprint would have been an expected and obvious result of applying Li’s HPLC-ELSD method to Compound Kushen Injection.
With respect to the recited relative retention times of the three unknown peaks, D-fructose, pinitol, D-glucose anhydrous, and sucrose, relative retention times are analytical properties produced by the chromatographic method and sample matrix. Once the HPLC-ELSD conditions are selected and the CKI sample is analyzed, the relative retention times of the resulting peaks are inherent characteristics of the resulting chromatogram. The mere recitation of relative retention time ranges does not render the method nonobvious where the underlying chromatographic method is an obvious optimization of Li’s HPLC-ELSD saccharide analysis method. Applicant has not shown that the recited relative retention times provide a critical or unexpected result beyond the expected result of optimizing chromatographic conditions to separate the target saccharides.
Regarding claim 5, Li teaches that wherein a flow rate of the mobile phase in the high-performance liquid chromatography-evaporative light scattering detection method is 1 ml/min (par [0061]).
Regarding claim 6, it would have been obvious to one of ordinary skill in the art to optimize the column temperature in the high-performance liquid chromatography-evaporative light scattering detection by routine experimentation.
Regarding claim 7, Li teaches that wherein an injection amount in the high-performance liquid chromatography-evaporative light scattering detection method is 10 μ L or 20 μL (par [0065]).
Regarding claim 8, It is well known in the art of ELSD sugar analysis that the drift tube temperature is adjusted empirically to achieve complete evaporation of solvent, adequate droplet drying, minimal thermal degradation and stable baseline.
Because Li already teaches the same sugars (pinitol, fructose, glucose, sucrose) and the same detection technique (HPLC-ELSD), one of ordinary skill in the art would have recognized that the drift tube temperature may be increased or decreased, the precise value depends on column conditions, solvent ratio, flow rate, and desired sensitivity. ELSD drift-tube temperatures in the sugar-detection literature commonly range from 40–80 °C, depending on aqueous mobile-phase proportion
Therefore, moving from Li’s 41 °C to applicant’s claimed 60 °C constitutes merely routine parameter optimization, without any unexpected results, yielding predictable performance improvements (e.g., better solvent removal under higher aqueous ratio).
Thus, it would have been obvious to one of ordinary skill in the art to optimize the evaporation temperature of the evaporation light detector in the high-performance liquid chromatography-evaporative light scattering detection by routine experimentation.
Regarding claim 9, in ELSD operation, the atomizing (nebulization) temperature is a result-effective variable, selected to ensure optimal aerosol formation, governed by solvent volatility, flow rate, and analyte stability.
Because Li performs HPLC-ELSD on aqueous–organic sugar samples, the skilled artisan would understand that atomizer temperature must be adjusted as needed, typical values range from 30–90 °C, and choosing a higher temperature improves droplet formation for aqueous-rich mobile phases.
It would have been obvious to one of ordinary skill in the art to optimize an Atomizing temperature of the evaporation light detector in the high-performance liquid chromatography-evaporative light scattering detection by routine experimentation.
Regarding claim 10, Nitrogen is the most common carrier gas used in ELSD. Thus, a PHOSITA would inherently choose nitrogen in the absence of any contrary teaching. Li’s ELSD settings assume a standard ELSD configuration; thus, nitrogen is the expected gas.
ELSD gas flow rate is a routine, result-effective parameter. Gas flow rate in ELSD affects aerosol droplet size, nebulization efficiency, signal strength, baseline noise. Thus, it would have been obvious to one of ordinary skill in the art to optimize the flow rate by routine experimentation.
Regarding claim 11, in HPLC practice, the blank (injecting solvent with no analyte) must be compatible with the mobile phase, to avoid peak distortion, baseline disturbances, or solvent-front artifacts.
Since Li’s method uses acetonitrile and water exclusively as the mobile phase components, a PHOSITA would automatically prepare the blank from the same solvents.
Choosing 50:50 ACN:H₂O is a routine choice. In carbohydrate analysis, 50:50 acetonitrile–water is one of the most common diluent/blank mixtures because it is miscible with both high-ACN and high-water regions of the gradient, stable toward ELSD nebulization, non-reactive with sugars. Thus, selecting 50:50 is ordinary optimization.
Regarding claim 12, Li teaches weighing the same four reference substances: pinitol, fructose, glucose, sucrose, dissolving them in solvent to prepare reference solutions for HPLC–ELSD detection (par [par [0064]). Use of these reference solutions to identify retention times and quantify sugar content for each analyte (par [0067]). Thus, Li teaches use of multiple reference standards of the same analytes, injected by ELSD for quantification.
A PHOSITA would understand that instead of running four separate reference solutions, it is standard and widely accepted practice to combine multiple analytes into a single mixed reference solution to reduce injection time, minimize solvent use, and improve calibration efficiency. This is a routine laboratory optimization.
Changing the concentration of reference standards is a result-effective variable.
Regarding claim 13, Li teaches taking a sample of the test liquid, diluting to a defined volume, dissolving in mobile-phase compatible solvent, filtering, using the filtrate as the test solution for HPLC–ELSD (par [0065]).
This is the same type of routine sample-prep step recited in Claim 13.
CKI is itself a liquid injection containing the analytes of interest (sugars). To run HPLC–ELSD, an aliquot must be taken, diluted to fall inside the detector’s linear range, filtered to remove particulates.
Li performs the same actions for its sample (carob extract liquid).
A PHOSITA analyzing CKI with the HPLC–ELSD method taught by Li would be motivated to dilute the CKI sample to appropriate levels for ELSD calibration, use the same solvent system (ACN/H₂O) to maintain solvent compatibility, filter the sample to protect the column and stabilize the baseline. This is exactly the same reasoning Li uses for its test solution preparation in par [0065].
Claim recited volumes (1 mL → 20 mL) and the use of CKI rather than carob extract are routine, non-critical, predictable modifications.
Regarding claim 14, Li teaches the same detector (ELSD) (par [0061]), the same four analytes (par [0064]), the same class of carbohydrate columns with identical dimensions (par [0061]), the same solvent system (ACN/H₂O) (par [0061]), similar ELSD tuning parameters (par [0061]), the same sample and standard preparation steps (par [0065]), and the same quantitation method (par [0067]).
The Table in Claim 14 merely provides routine, result-effective method parameters that a PHOSITA would predictably select when applying Li’s method to Compound Kushen Injection.
Regarding claim 15, Li teaches that the method comprises constructing a fingerprint of the sample containing D-glucose anhydrous, D-fructose, sucrose, and pinitol (par [0067][0068]).
Thus, simply substituting CKI into an already-known ELSD sugar fingerprinting method is obvious.
Regarding claim 16, the claim merely specifies routine, predictable HPLC–ELSD conditions for performing the same analysis already disclosed by Li.
Li provides same analyzer (ELSD) (par [0061]), same solvent system (par [0061]), same chromatographic hardware (par [0061]), same analytes (par [0064]), same sample-prep steps (par 0065]), same quantitation method (par [0067]).
The Table of parameters in Claim 16 contains only result-effective variables, all of which would have been obvious to optimize.
Regarding claim 18, the claim’s relative retention time (RRT) ranges fall within the expected variation created by different columns (ZORBAX vs Prevail), different temperatures (Li uses 35 °C; claim uses 15 °C), different ACN gradients, slight shifts in peak elution under ELSD.
A PHOSITA routinely expects 10–20% drift in retention time between instruments and expresses this number as an RRT range.
Response to Arguments
Applicant's arguments filed 05/22/2026 have been fully considered but they are not persuasive.
Applicant argues that Li does not teach or suggest the claimed column temperature range of 13°C to 20°C and that reducing Li's disclosed temperature of 35°C to the claimed range would not have been routine. Applicant further relies upon a Declaration alleging improved separation of fructose and pinitol under the claimed conditions.
The argument is not persuasive. Li teaches an HPLC-ELSD method for analyzing the same monosaccharides, including fructose, glucose, sucrose, and pinitol. The temperature of an HPLC column is a recognized result-effective variable that affects retention time, selectivity, and chromatographic resolution. Optimization of such parameters through routine experimentation is well within the level of ordinary skill in the chromatographic arts. The discovery of an optimum or workable value of a result-effective variable is ordinarily obvious. Therefore, adjustment of Li's operating temperature to obtain a desired degree of separation would have been an obvious matter of routine optimization.
Applicant's arguments regarding pH conditions, alleged differences in sample matrices, and alleged preferences of skilled artisans are also not persuasive because the pending claims do not recite any pH limitation or require any particular mechanism by which separation is achieved. Patentability must be determined on the basis of the limitations actually recited in the claims, rather than on unclaimed features discussed in the specification or Declaration.
Applicant additionally argues that Li does not disclose the claimed fingerprint containing three unknown peaks and four named-sugar peaks at the recited relative retention times. However, the recited fingerprint represents the natural analytical result obtained when the claimed sample is subjected to the recited chromatographic method. Relative retention times are properties of the separated analytes under the selected operating conditions and do not impart a structural difference to the method itself. The mere discovery or recognition of a previously unappreciated property or result of an otherwise obvious process does not render the process patentable. Furthermore, Applicant has not established that the recited retention-time values are critical or that they produce a result that would have been unexpected relative to what would ordinarily be obtained through routine optimization of chromatographic conditions.
Regarding the Declaration, the evidence is not commensurate in scope with the claims. The claims encompass a range of operating conditions, whereas the Declaration compares only a limited number of specific experimental conditions. The Declaration therefore does not establish that all embodiments falling within the scope of the claims exhibit the alleged improvement. Moreover, the evidence demonstrates at most an expected improvement in chromatographic resolution resulting from optimization of known chromatographic parameters and does not outweigh the evidence of obviousness provided by the prior art.
Accordingly, the rejection under 35 U.S.C. 103 is maintained.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to XIAOYUN R XU, Ph. D. whose telephone number is (571)270-5560. The examiner can normally be reached M-F 8am-5pm.
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/XIAOYUN R XU, Ph.D./Primary Examiner, Art Unit 1797
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