X-ray Photoelectron Spectroscopy (XPS) works by shining X-rays onto a sample surface and measuring the electrons released from the outermost layers. Because the energy of these electrons depends on the elements present and how they are chemically bonded, XPS can reveal surface composition, oxidation states, bonding environments, and trace contamination that may not be visible by bulk analysis. For drug development scientists, formulation teams, analytical project managers, and CRO partners, XPS provides information that bulk methods often cannot reveal: whether an API is enriched at a particle surface, whether an excipient coating is complete, whether a metal oxide exists in a specific oxidation state, or whether processing residues are driving unexpected performance changes. BOC Sciences offers comprehensive XPS Testing services for APIs, excipients, solid dispersions, polymeric carriers, coatings, nanomaterials, and process-contact surfaces. Our scientists design sample-specific XPS experiments, interpret high-resolution spectra, and integrate the results with complementary analytical testing to help clients convert complex surface chemistry data into actionable formulation, process, and material decisions.
We perform survey-scan XPS analysis to determine the near-surface elemental profile of pharmaceutical solids, coatings, particles, and functional materials, supporting both standalone investigations and broader analysis and purification programs.
Our high-resolution XPS methods provide chemical-state information that supports structure characterization of surfaces where oxidation, salt formation, surface functionalization, or bonding changes may affect product behavior.
BOC Sciences helps identify surface-originated issues that may arise from processing aids, container contact, cleaning residues, adsorbed organics, metal traces, or environmental exposure, complementing heavy metal analysis and targeted residue studies.
For coatings, layered materials, modified particles, and oxide films, we provide depth-resolved and spatially resolved XPS strategies that can be integrated with elemental and material analysis technologies.
BOC Sciences delivers scientifically interpreted XPS data for APIs, excipients, coatings, particles, and functional materials, helping teams identify surface composition, chemical states, contamination sources, and interface behavior.
We use monochromatic X-ray excitation and carefully selected acquisition parameters to generate high-quality survey and narrow-scan spectra for pharmaceutical solids, polymers, inorganic materials, and hybrid drug delivery systems.
Our scientists apply peak fitting, background selection, charge correction, and chemical-state interpretation to distinguish overlapping components and translate binding energy shifts into meaningful surface chemistry assignments.
Many APIs, excipients, coatings, and polymeric materials are electrically insulating. We optimize charge neutralization and referencing strategies to reduce peak shifting and improve confidence in chemical-state analysis.
By combining XPS acquisition with carefully controlled ion etching, including Ar+-based approaches when suitable, we examine coating thickness trends, oxide layers, surface treatments, and buried interfaces.
XPS findings can be integrated with spectroscopy testing, X-ray fluorescence testing, ICP, Raman, XRD, and thermal techniques to build a stronger material evidence package.
We design XPS studies around the actual project question, whether the goal is identifying a residue, verifying a functionalized surface, comparing API particles, or evaluating an ultrathin coating.
BOC Sciences provides XPS Testing for vacuum-compatible pharmaceutical, chemical, polymeric, inorganic, and hybrid materials. Our team helps clients determine whether the submitted sample is suitable for XPS, how it should be mounted, and whether complementary techniques are recommended for a more complete interpretation.
Submit your sample description, formulation context, suspected issue, or target surface chemistry. Our analytical scientists will design a focused XPS strategy tailored to your material and project objective.
We review the sample type, expected composition, surface question, handling sensitivity, vacuum compatibility, and available background data to determine whether XPS alone or a combined analytical plan is most suitable.
Our team defines the analysis area, mounting approach, survey and high-resolution regions, charge compensation strategy, and optional depth-profiling or mapping conditions while minimizing handling-related surface contamination.
We acquire survey and narrow-scan spectra, calculate surface atomic composition, assign chemical states, compare representative samples, and perform peak fitting when chemically meaningful and technically justified.
The final report presents spectra, atomic percentages, peak assignments, depth or mapping results when applicable, interpretation notes, and practical recommendations for formulation, process, material, or further analytical decisions.
Pharmaceutical and polymeric samples can adsorb hydrocarbons, silicone residues, metal traces, or handling-related contaminants that dominate the first few nanometers of the surface. BOC Sciences uses careful sample handling, comparative controls, high-resolution peak interpretation, and optional complementary element analysis to separate meaningful material chemistry from incidental surface contamination.
APIs, excipients, polymers, oxides, and coated particles frequently charge during XPS acquisition, causing binding energy shifts and ambiguous assignments. Our approach combines charge neutralization, reference peak selection, replicate checks, and chemically consistent fitting models to improve confidence when interpreting C 1s, O 1s, N 1s, S 2p, P 2p, and halogen-containing spectra.
Bulk assays may miss API or excipient segregation at particle surfaces, while XPS may reveal only the outermost chemistry. BOC Sciences integrates XPS with API analysis, XRD testing, thermal analysis, and particle-level characterization to help clients understand whether surface enrichment reflects formulation design, process drift, or material incompatibility.
Metal-containing particles, oxide films, catalyst traces, inorganic excipients, and salts can produce overlapping peaks or multiple oxidation states. We combine high-resolution XPS fitting with reference-informed interpretation and optional ICP testing, XRF, or microscopy-based approaches to distinguish true chemical-state changes from mixed-surface artifacts.
Collaborate with BOC Sciences to investigate surface composition, oxidation states, coating uniformity, contamination sources, and material interfaces through expert XPS Testing supported by multidisciplinary analytical insight.
We help clients answer surface-specific questions that directly influence formulation behavior, particle performance, coating function, material compatibility, and process troubleshooting.
Our reports emphasize chemically meaningful assignments, comparative interpretation, peak-fitting rationale, and project-relevant conclusions rather than isolated spectral outputs.
XPS can be combined with Raman testing, thermal analysis, XRD, XRF, chromatography, and microscopy to resolve complex material questions from multiple perspectives.
From API powders and polymer coatings to inorganic particles and treated surfaces, our team adapts XPS acquisition and interpretation strategies to the physical nature of each sample.
Client Needs: A formulation team observed variable dissolution behavior in a spray-dried amorphous dispersion containing a weakly basic API and a cellulosic polymer. Bulk assays showed comparable composition, but the team suspected surface-level API enrichment after process scale-up.
Challenges: The sample was electrically insulating, highly organic, and prone to adventitious carbon contamination. The analytical question required differentiating API-specific nitrogen and aromatic carbon signals from polymer-related oxygen-rich surface chemistry.
Solution: BOC Sciences mounted representative powder fractions under low-contamination handling, acquired survey spectra and high-resolution C 1s, O 1s, and N 1s scans across twelve particle areas, and applied charge compensation with consistent C 1s referencing. We compared API-rich spectral markers against polymer-rich controls and correlated findings with DSC testing and XRD results.
Outcome: XPS confirmed higher API-related nitrogen and aromatic carbon contributions at the particle surface in the scale-up batch, supporting process adjustment of drying conditions and feed concentration.
Client Needs: A chemistry group needed to determine whether a pale surface discoloration on an API intermediate was associated with an inorganic oxide, a trace metal-containing residue, or an organic process impurity.
Challenges: The visible discoloration was localized and the total residue level was low. Conventional bulk testing did not reflect the surface chemistry responsible for the appearance change.
Solution: We selected stained and unstained regions for small-area XPS acquisition, collected high-resolution Fe 2p, O 1s, C 1s, and Cl 2p spectra, and used comparative peak fitting to separate oxide, hydroxide, and organic chloride contributions. The XPS evidence was integrated with X-ray powder diffraction and targeted metal screening.
Outcome: The surface discoloration was linked to a thin iron oxide/hydroxide-rich residue rather than a bulk impurity, allowing the client to focus investigation on contact surfaces and final isolation handling.
Client Needs: A drug delivery research team required confirmation that amine-functionalized polymeric nanoparticles retained surface nitrogen functionality after ligand coupling and purification.
Challenges: The functional layer was expected to be ultrathin, and the dried nanoparticles contained overlapping carbon, oxygen, and nitrogen environments from the polymer matrix, linker, and residual processing materials.
Solution: BOC Sciences prepared dried nanoparticle deposits on clean conductive substrates, acquired replicate survey scans and high-resolution N 1s/C 1s spectra, and compared unmodified, activated, and ligand-coupled samples. We used nitrogen chemical-state fitting, surface atomic percentage trends, and control-subtracted interpretation to confirm coupling-associated signal changes while screening for residual salts and processing additives.
Outcome: The XPS dataset confirmed increased surface nitrogen contribution and a shifted N 1s component consistent with ligand coupling, helping the client refine washing conditions and surface functionalization parameters.
XPS testing is suitable for pharmaceutical and advanced material samples that require surface-sensitive chemical characterization, including drug crystals, inorganic salts, metal oxides, nanocarriers, polymer excipients, coatings, implant-related materials, functionalized particles, and drug delivery materials. Because XPS mainly probes the outermost surface region, it is especially useful when researchers need to determine whether surface modification, oxidation, coating, or contamination has occurred. BOC Sciences can design wide-scan analysis, high-resolution spectra, elemental quantification, chemical-state interpretation, and depth profiling based on the sample type and project objective.
XPS provides elemental composition, relative atomic percentages, chemical states, oxidation states, binding energy shifts, and information about the chemical environment of specific elements on a material surface. In drug development and material characterization, clients often need more than a simple list of detected elements. They may need to know whether a metal exists in a specific oxidation state, whether carbon-containing groups such as C–O, C=O, or O–C=O are present, or whether fluorination, silanization, or oxidation has changed the surface chemistry. High-resolution XPS and peak fitting can provide deeper insight into these surface-level chemical differences.
Many performance-related differences in pharmaceutical materials originate at the surface rather than in the bulk structure. XPS is highly valuable because it helps reveal the surface chemistry responsible for wettability, dispersibility, interfacial compatibility, adsorption behavior, particle interaction, and batch-to-batch variation. It is commonly used to evaluate coated particles, modified polymers, nanomaterials, inorganic carriers, surface-treated powders, and multilayer materials. BOC Sciences supports clients by linking XPS spectra with the actual development question, helping researchers understand not only what is present on the surface, but also how that surface chemistry may influence material behavior.
XPS depth profiling helps determine whether a coating, oxidation layer, surface treatment, contaminant, or functional layer is limited to the outer surface or extends into the subsurface region. This is particularly useful for multilayer coatings, functionalized nanoparticles, inorganic drug carriers, polymer films, and composite materials. By combining XPS analysis with controlled profiling strategies, researchers can evaluate elemental distribution, chemical-state changes, interfacial transitions, and surface layer uniformity. BOC Sciences selects appropriate profiling approaches based on material sensitivity to reduce the risk of misleading interpretation caused by surface damage or unwanted chemical alteration during analysis.
Samples for XPS testing should be handled carefully to avoid surface contamination, because the technique analyzes only the outermost region of the material. Powders should be protected from direct contact, unnecessary exposure, and external residues. Films, coatings, and solid samples should retain the target surface intended for analysis. Clients should also provide information about surface treatment, washing, drying, storage conditions, expected elements, possible chemical states, and available control samples. For insulating or beam-sensitive materials, BOC Sciences considers charge correction and data interpretation strategies in advance to help generate reliable and meaningful XPS results.
Our team had bulk data but no explanation for the particle performance shift. BOC Sciences used XPS to show what changed at the surface and helped us focus our formulation work immediately.
— Dr. Manning, Senior Formulation Scientist
The value was not just the spectra. Their scientists explained the peak assignments, the limitations, and how the XPS results connected with our existing analytical data. That made the findings much easier to use internally.
— Mercer, Analytical Development Manager
We submitted several visually similar samples with a subtle surface defect. BOC Sciences identified the chemical difference between them and gave us a logical route to investigate the source.
— Vaughn, Process Chemistry Lead
Our coating project required evidence of surface modification without relying on bulk measurements alone. The XPS study was carefully designed, clearly reported, and directly useful for our material optimization work.
— Sheridan, Drug Delivery Project Director
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