Reveal details of your chemical's molecular structure in solids and liquids.
Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful tool for identifying and characterizing pharmaceuticals and other chemicals. It is commonly used to determine the structure of both known and novel compounds, meeting regulatory and research requirements for chemical identity. NMR can reveal how atoms are connected within a molecule, in both solid and liquid phases, by analyzing the chemical environment of a selected atomic nucleus. Isotopes with an odd number of protons and/or neutrons have a nuclear magnetic moment and angular momentum, or nonzero nuclear spin, while those with even numbers of both have a total spin of zero. The most frequently studied nuclei are ¹H (proton) and ¹³C (carbon). By examining the peaks of NMR spectra, the structure of many compounds can be identified. This technique is highly selective, distinguishing between atoms within a molecule or collection of molecules that differ only in terms of their local chemical environment.
Services we offer:
- Solution or Liquid State Nuclear Magnetic Resonance (NMR) Analysis
- 1D 1H and 13C NMR spectroscopy. 15N, 19F, 31P, other nuclei also available for routine analyses
- Solid State Nuclear Magnetic Resonance (NMR) Analysis
- 13C, 31P, and 19F and other nuclei with broadband probe
- cGMP Nuclear Magnetic Resonance (NMR) Analysis
- Quantitative Nuclear Magnetic Resonance (qNMR) Analysis
- 2D Nuclear Magnetic Resonance (NMR) Analysis
- COSY, NOESY, TOCSY, HMQC, HSQC, HMBC with resonance assignments to provide detailed information on chemical structure and conformation. Rapid interpretation of spectra
Nuclear Magnetic Resonance Analysis is useful for:
- Analysis of formulations (deformulation of solids and liquids)
- Analysis of stereo isomers (solids and liquids)
- Characterization of polymorphs, solvates, salts, cocrystals, and non-crystalline (amorphous) materials
- Characterize crystalline form of a drug present in a final product
- Chemical exchange analysis (solids and liquids)
- Comparability studies of biologics (biosimilarity)
- Confirm the number of molecules in the asymmetric unit (solids)
- Conformational and structural analysis (solids and liquids)
- Determining absolute purity
- Determine chemical composition in a range of insoluble polymers and plastics
- Identification and quantification of impurities and contaminants (solids and liquids)
- Identify and quantify components in polymer blends without the need for calibration standards
- Identifying a generic API
- Identity confirmation of excipients used in pharmaceutical formulations
- Molecular mobility analysis (solids and liquids)
- Patent prosecution and litigation support. Expert (testifying and non-testifying) services, reproduction of prior art. See our Chemical Intellectual Property Expert Services page (click here) for more details
- Primary reference material (PRM) verification
- Product Failure Analysis
- Qualitative and quantitative NMR method development, validation, release testing, method transfer
- Verification and execution of USP, EP, JP other compendial NMR methods
Our Instrumentation and Capabilities:
| Instrument | Models, Probes, Software | Additional Info |
| Bruker | 400MHZ ultrashield, Avance AVII cGMP and non cGMP Liquids, multi-nuclear (1H, 13C, 31P, 19F, 15N, and others with broadband probe) non cGMP Solids, multi-nuclear (13C, 31P, and 19F and others with broadband probe) Topspin 3.2 Software as well as multiple spectral analysis software packages |
In support of The United States Pharmacopoeia (USP) General Chapter <761> Nuclear Magnetic Resonance Spectroscopy and other Compendial chapters (e.g., <1761>), Triclinic Labs offers multi-dimensional cGMP liquids analysis with a broadband probe allowing for a myriad of experiments (1H, 13C, 15N, 19F, 31P, etc.) at variable temperatures (233 - 350K). |
How does Nuclear Magnetic Resonance Analysis work?
When nuclei are placed into a magnetic field, their magnetic moment (spin) becomes aligned with the magnetic field. NMR uses a pulse of radio frequency energy to deflect the nuclei. When the energy is removed, the nuclei relax back to their original state and emit an electromagnetic pulse. A coil inside the NMR receives this RF pulse, and a computer transforms the signal into a spectral graph, which can be interpreted by a spectroscopist. Each nucleus that resides in a unique chemical environment, based upon the chemical structure, translates into a peak in the NMR spectrum. Its peak position (x-axis chemical shift value) and the multiplicity of the peak tells the scientist about its environment. The area of the peak corresponds to the number of nuclei producing the signal so this relationship allows for quantitative analysis.
A combination of 1-dimensional and 2-dimensional NMR experiments are usually necessary for complete confidence in complex chemical structures. The process of discerning structure typically involves: 1-dimensional proton ¹H-NMR and Carbon NMR are used to confirm the number of hydrogens and carbons in the molecule, respectively.
- ¹H-¹H Correlation Spectroscopy (COSY) identifies the correlation between hydrogens
- ¹H-¹³C Heteronuclear Single Quantum Coherence Spectroscopy (HSQC) identifies which hydrogens are attached to which carbon atoms.
- ¹H-¹³C Heteronuclear Multiple Bond Correlation Spectroscopy (HMBC) shows the correlations between protons and carbons with multiple bonds
- Other nuclei may be explored (e.g. 19F, 15N, 31P)
Types of NMR:
Solid State NMR
Solid-state nuclear magnetic resonance (ssNMR) is a specialized characterization technique used to determine the chemical composition or structural properties in various materials. Solid-state NMR provides detailed chemical structural information and quantification without the need for standards, similar to solution NMR. Our scientists utilize this unique technique in combination with others, such as FT Raman and Powder X-ray diffraction (PXRD), to address challenging material or process problems.
Solution or Liquid State NMR
The analysis of chemical systems, liquids, and solids using Solution or Liquid state NMR provides valuable data about the type, quantity, and arrangement of different atoms. Samples are dissolved in deuterated solvents and can often be recovered after the measurement of important samples. NMR is a key technique for structure determination.
Quantitative NMR
What is qNMR?
NMR spectroscopy analyzes molecules at the atomic level, detecting protons or carbons, making NMR one of the most universal techniques. qNMR takes advantage of the fact that the peak area (integration) in NMR spectroscopy is directly proportional to the concentration of the specific component in solution. This feature allows for determination of relative concentration of each component in a mixture. For absolute quantitation, a certified reference material (CRM) is utilized either as an internal or external standard. The CRM is not chemically related to any of the components in question, and therefore, the same CRM can be used for the quantitation of a wide variety of test articles.Quantitative NMR, or qNMR, is used for the determination of the concentration and purity of small molecules. The qNMR method only requires that (a) the sample dissolves completely in a (normally fully deuterated) solvent, and (b) it contains NMR-active nuclides.
There are two broad categories of qNMR experiments: those used to determine the analyte concentration, and those used to determine a compound's purity.
- qNMR can provide fast and low-cost quality control (QC) tests such as identification, purity and potency tests, without the corresponding reference standard materials
- qNMR is also useful in the investigation of unknowns and product failure
Why qNMR?
NMR spectroscopy is one of the most universal techniques used in identification of chemical components. qNMR is a relatively simple but versatile technique that can perform the identification testing and simultaneously determine the concentration of one or more components in a test article without having the requirement of certified reference standard materials of each of the corresponding compounds. qNMR can be used for purity assay, potency determinations, investigation of unknowns, investigation of product failures, and as a part of quality control (QC) tests.Using qNMR and Regulatory Requirements:
United States Pharmacopoeia (USP) chapter <761> Nuclear Magnetic Resonance Spectroscopy describes qNMR under Qualitative Applications. For absolute quantitation, a CRM is used as an internal or an external standard. The internal standard is co-dissolved in the solution with test articles. The external standard solution is placed in an insert within the NMR tube that contains the test solution. The CRM is not chemically related to any of the components in question. This simplifies the GMP validation procedure since a limited number of CRM in a small number of solvents can be validated for linearity, range, accuracy, precision, quantitation limit and robustness. For each new test article, only specificity needs to be validated as long as the same solvent system and experimental parameters are used.Pros and Cons of qNMR:
Pros of qNMR:- qNMR is a primary method where the signal intensity depends directly on the number of protons and concentration.
- Quick and simple analysis of test articles to identify and quantify components. Quantitative information such as purity of drug substances, potency of drug products can be obtained by qNMR.
- Unlike chromatographic methods, reference standard materials of the corresponding compounds are not required. This is especially advantageous during drug product development when reference standards of the active ingredients and impurities are not available.
- Unlike HPLC-UV methods, there is no response factor calculation required for active ingredients and impurities.
- Unlike HPLC methods, water or volatile content analysis (by KF or TGA) are not required for the purity determination.
- A number of CRM are commercially available.
Cons of qNMR:
- Applied to components with known chemical structures.
- The CRM selected must have a specificity against the NMR peaks related to the test sample.
- The test article must have detectable nuclei (such as proton or carbon).
- For mixture analysis, all components of interest must be soluble in a deuterated solvent or solvents.
Common Applications of qNMR:
- Identification and purity testing of pure components such as active pharmaceutical ingredients (APIs) and excipients.
- Identification and potency testing of drug product intermediates during product development and stability testing.
- Identification and potency testing, as a part of a release and stability study, of drug product intermediates and final products such as tablets, capsules, solutions, suspensions, granules, and powders.
- Concentration determination of each component in mixtures. The mixtures can be solids, solutions or suspensions.
- Investigation of product failure
- Food sciences
Mini Case Study:
qNMR Potency Testing of Generic Excedrin Tablets
Three different generic brands claiming equivalence to Excedrin Migraine Tablets were dissolved in DMSO-d6 with maleic acid as an internal standard. The label claims were evaluated and are provided in the table below. None of the generics we tested matched the label claims.| Components | Dosage Label Claim (mg/tablet) |
Actual Dosage
Product 1 |
Actual Dosage
Product 2 |
Actual Dosage
Product 3 |
| Acetaminophen | 250 | 98% | 83% | 110% |
| Aspirin | 250 | 101% | 98% | 66% |
| Caffeine | 65 | 115% | 115% | 107% |
| Comments | Contains Salicylic acid (See Figure Below) |
Figure 1. Salicylic acid is an active metabolite of aspirin (acetylsalicylic acid), which acts in part as a prodrug to salicylic acid, it is probably best known for its use as a key ingredient in topical anti-acne products.
Pharmaceutical Applications of NMR:
Uses of NMR in Current Guidance for Pharmaceutical Quality/CMC:
Under current regulations in the United States, use of a human drug product not previously authorized for marketing in the United States requires the submission of an IND to the Agency. FDA's regulations at 21 CFR 312.22 and 312.23, respectively, contain the general principles underlying the IND submission and the general requirements for content and format. Section 312.23(a)(7)(i) requires that an IND for each phase of investigation include sufficient Chemistry Manufacturing and Controls (CMC) information to ensure the proper identity, strength or potency, quality, and purity of the drug substance and drug product. The FDA or other regulatory agencies usually require full structural characterization by NMR. This data provides crucial evidence of compound identity.
Other CMC Services we offer:
- Chemical name
- Structure figure
- Molecular formula
- Molecular weight
- Elemental analysis (CHN)
- UV/VIS spectroscopy
- IR spectroscopy
- Raman spectroscopy
- Mass spectrometry
- Optical, Specific rotation
- Phase identification by XRPD
- Ion Chromatography
- Single crystal X-ray Structure Elucidation
