Characterize and control amorphous materials when crystalline approaches are insufficient

Some low-solubility compounds improve with micronization; others do not dissolve adequately regardless of particle size. When salt selection, cocrystal development, micronization, or crystalline-form selection cannot solve exposure risk, amorphous materials or amorphous solid dispersions may be appropriate.

X-ray amorphous does not mean structurally featureless

A non-crystalline material produces an essentially continuous XRPD pattern often called an X-ray amorphous pattern. That pattern can still contain information about local molecular order, short-range packing, and structural change.

Triclinic applies total diffraction analysis, molecular modeling, thermal methods, spectroscopy, microscopy, and stress studies to understand whether a non-crystalline material is stable enough to carry through development and shelf life.

XRPD amorphous halo
Continuous X-ray diffraction pattern / amorphous halo used to illustrate an X-ray amorphous, non-crystalline material. Source: Triclinic Labs, Non-Crystalline and Amorphous Material Analysis Services.
Amorphous local molecular structure
Calculated local molecular order model used to illustrate how non-crystalline materials can retain short-range molecular structure. Source: Triclinic Labs, Non-Crystalline and Amorphous Material Analysis Services.

That distinction matters because amorphous materials with similar bulk XRPD appearance may differ in local order, water response, and crystallization tendency. A useful amorphous study therefore compares how the amorphous halo, thermal behavior, spectroscopic signal, and stability response change with production route and stress condition.

ASD and spray-drying development

Triclinic guides amorphous material development by evaluating stability of materials produced by different routes, comparing formulations, and developing assays to determine whether material remains amorphous or contains crystalline components.

Spray drying rapidly evaporates solvent from solution microdroplets, reducing the opportunity for API molecules to reorient and crystallize compared with bulk evaporation. Small-scale spray drying can be evaluated as part of polymorph or amorphous screening when the API has suitable thermal and solvent properties.

ASD questionDevelopment implicationTriclinic evaluation
Is the API a fast or slow crystallizer?Fast crystallizers may require stronger polymer selection or different processing.Amorphous generation, stress, and recrystallization testing.
What is the solubility advantage?ASD only helps if the amorphous state provides a useful performance gain.Dissolution and supersaturation comparison against crystalline material.
Which polymer and loading are appropriate?Polymer choice and drug loading control stability, manufacturability, and performance.Polymer toolbox screen, loading assessment, and stability ranking.
What storage conditions are needed?Temperature and humidity can drive physical aging or recrystallization.Tg, DVS, controlled RH/temperature stress, and phase-specific analysis.
Spray-drying amorphous material development formula graphic
Spray-drying candidate-assessment relationship used for amorphous material development, including melting temperature and Tg considerations. Source: Triclinic Labs, Amorphous Material and Solid Dispersion Development Services.

Dissolution testing should be paired with residual-solid analysis. Apparent performance can look acceptable while crystallization is occurring in a subset of particles or after polymer dissolution, especially when phase separation is present.

How Triclinic scopes amorphous material and ASD development

An amorphous strategy should start with the performance problem and the failure mode, not with the assumption that every poorly soluble compound belongs in an ASD. Triclinic first separates solubility limitation, dissolution-rate limitation, crystallization tendency, moisture sensitivity, and formulation matrix effects so the study is aimed at the decision the program actually has to make.

The practical output is a control recommendation: whether an amorphous route is justified, which processing and polymer variables deserve testing, which residual-solid analyses are required after dissolution, and which method can detect recrystallization or unintended crystalline content at the relevant development stage.

  1. Define the performance problem. Confirm whether the issue is solubility, dissolution rate, supersaturation maintenance, crystallization during dissolution, or stability during storage.
  2. Generate and stress relevant materials. Compare neat amorphous API, spray-dried dispersions, polymer matrices, humidity and temperature stress, and post-dissolution residual solids where applicable.
  3. Use phase-specific analysis. Combine XRPD or total diffraction with DSC or mDSC, DVS, Raman or LF Raman mapping, microscopy, and stability studies so crystallinity and local order are not inferred from performance data alone.
  4. Translate results into a control path. Recommend polymer, loading, processing, storage, and analytical-monitoring next steps based on recrystallization risk and formulation performance.

Confirm whether amorphous performance is durable or temporary

Amorphous content can raise apparent solubility and dissolution, but it also increases recrystallization and moisture-sensitivity risk. A strong amorphous-material program separates short-term performance from a physical state that can be maintained through processing, storage, and use.

Residual-solid analysis matters because attractive dissolution or PK may reflect a temporary amorphous, mixed, hydrated, or solvated state rather than a developable material strategy.

Decision signalWhat to testActionable output
Apparent solubility gainThe non-crystalline state may temporarily increase supersaturation.Pair dissolution with residual-solid and stability analysis.
Moisture sensitivityWater can plasticize amorphous material and accelerate recrystallization.Use DVS, DSC/Tg, PXRD, Raman/ssNMR, and controlled humidity stress.
ASD feasibilityPolymer choice and drug loading determine whether performance can be maintained.Rank formulation candidates by stability, dissolution, and phase-specific characterization.
Case Studies examples graphic

Examples and Publications.

Amorphous-material examples

Application-note examples include mDSC-based quantitation of amorphous content in crystalline API, rapid ASD development using nifedipine, and evaluation of acetaminophen spray-dried dispersions by low-frequency Raman mapping.

These examples highlight the same practical requirement: do not rely on performance data alone. Link dissolution, solubility, Tg, water uptake, and stability behavior to phase-specific solid-state analysis.

Amorphous halo peak width broadening
Amorphous halo peak-width broadening used to illustrate how continuous XRPD features can be modeled to assess random packing and local disorder. Source: Triclinic Labs, Non-Crystalline and Amorphous Material Analysis Services.

Other services available

Polymorph Screening and Selection

Determine whether an API can exist in multiple crystalline forms and whether form differences change solubility, dissolution, stability, manufacturing, drug-product performance, or IP.

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Pharmaceutical Salt Screening and Selection

Screen ionizable APIs for counterions that improve crystallinity, solubility, dissolution, stability, manufacturability, or developability while controlling disproportionation risk.

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Cocrystal Screening and Development

Use coformer selection, phase-diagram logic, crystallization methods, and formulation strategy to improve properties and expand solid-form options.

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Crystallization Method Development

Build reproducible crystallization processes that control the chosen solid form, particle attributes, purity, and scale-up behavior.

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Manufacturing Troubleshooting

Resolve form conversion, failed crystallizations, process sensitivity, stability drift, unexplained PK/dissolution changes, and batch-to-batch material differences.

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Common Questions

When is an amorphous or ASD strategy appropriate?

When crystalline forms, salts, cocrystals, or micronization do not provide adequate solubility, dissolution, or exposure.

What is the main risk?

Physical instability: amorphous material can phase separate, physically age, absorb water, or recrystallize during processing, storage, or dissolution. We can model the material and determine it's long and short term stability. 

What must be controlled?

Form, crystallinity, Tg behavior, humidity response, polymer compatibility, drug loading, dissolution performance, and method specificity in API or drug product.

How should recrystallization risk be evaluated?

Recrystallization risk should be evaluated under relevant temperature, humidity, processing, storage, and dissolution conditions using orthogonal methods such as XRPD or total diffraction, DSC or mDSC, DVS, Raman or LF Raman mapping, microscopy, and stability studies.

Free consultation with Triclinic Labs

Talk to a Triclinic Labs scientist about Amorphous Material and ASD Development

Send the material history, current data package, process conditions, development objective, and timeline. Triclinic will route the request to the right solid-form scientist.

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