S&T

Amorphous materials can pose a range of challenges in product processing, storage, and performance.

They exhibit distinct properties from their crystalline counterparts, and while amorphous content may be introduced intentionally in some cases, it can also be generated unintentionally through processes such as milling, spray drying, or wet granulation.

Even amorphous content of less than 10% of the total can significantly affect overall product characteristics. Using Dynamic Vapor Sorption (DVS) technology, the amount of amorphous material present can be quantitatively determined, helping researchers more accurately understand product properties.

Pharmaceuticals

In pharmaceuticals, a certain level of amorphous content may be desirable as it can enhance drug bioavailability and dissolution. However, techniques capable of precisely measuring low levels of amorphous content are limited, and among them, Gravimetric Vapor Sorption (DVS) is regarded as one of the most sensitive analytical methods.

The method described in the application note below involves measuring the octane sorption of known standard samples to construct a calibration curve for amorphous content, which is then used to quantify amorphous content in unknown samples by measuring their octane sorption. Additionally, Inverse Gas Chromatography (IGC) can be used to sensitively calculate low levels of amorphous content in pharmaceutical substances based on surface energy.

The application notes below provide further detail on amorphous content measurement methods using DVS and iGC-SEA.

DVS Application Note 34: A New Gravimetric Method to Calculate Low Levels of Amorphous Content.

[Request a copy] iGC-SEA Application Note 212: The Characterisation of Amorphous Material by Inverse Gas Chromatography. [Request a copy]

Polymers

The crystallinity of amorphous polymers has a decisive influence on their final thermal, mechanical, and chemical properties. Using Inverse Gas Chromatography (IGC), polymer crystallinity can be directly evaluated by quantifying retention behavior during the melting transition.

The application note below summarizes a case of amorphous content quantification in polyethylene using the IGC method.

iGC-SEA Application Note 303: An Overview of iGC-SEA – a New Instrument for Characterising the Physico-Chemical Properties of Polymers. [Request a copy]

Hydrates and Solvates

When an amorphous sample forms a hydrate or solvate, the amorphous content of the sample can be calculated without the need for an amorphous reference standard.

This Dynamic Vapor Sorption (DVS) method is based on the principle that the sorption uptake associated with hydration or solvation is directly proportional to the amorphous content of the sample.

This is because the amorphous phase responds more sensitively to hydration or solvation than the crystalline phase. The application note below explains in greater detail how this method is applied to amorphous theophylline and carbamazepine.

DVS Application Note 44: Determining Amorphous Contents without a Standard: Hydrate/Solvate Stoichiometry. [Request a copy]

Amorphous materials can pose a range of challenges in product processing, storage, and performance. They exhibit distinct properties from their crystalline counterparts, and while amorphous content may be introduced intentionally in some cases, it can also be generated unintentionally through processes such as milling, spray drying, or wet granulation.

Even amorphous content of less than 10% of the total can significantly affect overall product characteristics. Using Dynamic Vapor Sorption (DVS) technology, the amount of amorphous material present can be quantitatively determined, helping researchers more accurately understand product properties.

Pharmaceuticals

In pharmaceuticals, a certain level of amorphous content may be desirable as it can enhance drug bioavailability and dissolution. However, techniques capable of precisely measuring low levels of amorphous content are limited, and among them, Gravimetric Vapor Sorption (DVS) is regarded as one of the most sensitive analytical methods.

The method described in the application note below involves measuring the octane sorption of known standard samples to construct a calibration curve for amorphous content, which is then used to quantify amorphous content in unknown samples by measuring their octane sorption. Additionally, Inverse Gas Chromatography (IGC) can be used to sensitively calculate low levels of amorphous content in pharmaceutical substances based on surface energy. The application notes below provide further detail on amorphous content measurement methods using DVS and iGC-SEA.

DVS Application Note 34: A New Gravimetric Method to Calculate Low Levels of Amorphous Content. [Request a copy] iGC-SEA Application Note 212: The Characterisation of Amorphous Material by Inverse Gas Chromatography. [Request a copy]

Polymers

The crystallinity of amorphous polymers has a decisive influence on their final thermal, mechanical, and chemical properties. Using Inverse Gas Chromatography (IGC), polymer crystallinity can be directly evaluated by quantifying retention behavior during the melting transition. The application note below summarizes a case of amorphous content quantification in polyethylene using the IGC method.

iGC-SEA Application Note 303: An Overview of iGC-SEA – a New Instrument for Characterising the Physico-Chemical Properties of Polymers. [Request a copy]

Hydrates and Solvates

When an amorphous sample forms a hydrate or solvate, the amorphous content of the sample can be calculated without the need for an amorphous reference standard. This Dynamic Vapor Sorption (DVS) method is based on the principle that the sorption uptake associated with hydration or solvation is directly proportional to the amorphous content of the sample. This is because the amorphous phase responds more sensitively to hydration or solvation than the crystalline phase. The application note below explains in greater detail how this method is applied to amorphous theophylline and carbamazepine.

DVS Application Note 44: Determining Amorphous Contents without a Standard: Hydrate/Solvate Stoichiometry. [Request a copy]