Podcast
Questions and Answers
Which amino acid residues are the principle sites of deamidation in alkaline pH for hGH?
Which amino acid residues are the principle sites of deamidation in alkaline pH for hGH?
Which amino acid residue is the major oxidative site in hGH?
Which amino acid residue is the major oxidative site in hGH?
How many Zn+2 binding sites are present in the primary structure of hGH?
How many Zn+2 binding sites are present in the primary structure of hGH?
Where does deamidated hGH occur inside the body?
Where does deamidated hGH occur inside the body?
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What can counteract hGH aggregation due to hydrophobic interactions when unfolded?
What can counteract hGH aggregation due to hydrophobic interactions when unfolded?
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How do sugar and glycine stabilize proteins in the liquid state?
How do sugar and glycine stabilize proteins in the liquid state?
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What technique traps proteins and stabilizes the formulation through glass stabilization?
What technique traps proteins and stabilizes the formulation through glass stabilization?
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How should reconstituted hGH be stored to prevent concentration-induced aggregation?
How should reconstituted hGH be stored to prevent concentration-induced aggregation?
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What does freeze-drying involve to produce proteins in a dry form?
What does freeze-drying involve to produce proteins in a dry form?
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What can impact pH due to lower solubility at lower temperatures?
What can impact pH due to lower solubility at lower temperatures?
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What can affect the stability of molecules during freezing?
What can affect the stability of molecules during freezing?
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What can cause protein degradation during freezing and drying?
What can cause protein degradation during freezing and drying?
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What is spray drying used for?
What is spray drying used for?
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What factors can be controlled in spray drying to affect the drying rate?
What factors can be controlled in spray drying to affect the drying rate?
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What increases the dry capacity of gas in spray drying, affecting liquid evaporation and drying rate?
What increases the dry capacity of gas in spray drying, affecting liquid evaporation and drying rate?
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What is the likely outcome to the residual water content in the powder using a drying gas with high temperature and low humidity at a high aspirator flow?
What is the likely outcome to the residual water content in the powder using a drying gas with high temperature and low humidity at a high aspirator flow?
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What is the purpose of using a freezing medium like liquid nitrogen in spray freeze drying?
What is the purpose of using a freezing medium like liquid nitrogen in spray freeze drying?
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Which chromatographic method is suitable for detecting protein aggregation?
Which chromatographic method is suitable for detecting protein aggregation?
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What information does Far UV CD (190-240nm) provide in circular dichroism (CD) spectroscopy?
What information does Far UV CD (190-240nm) provide in circular dichroism (CD) spectroscopy?
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What does Fourier transform infrared (FTIR) spectroscopy focus on in the Amide 1 region (1600-170 cm^-1)?
What does Fourier transform infrared (FTIR) spectroscopy focus on in the Amide 1 region (1600-170 cm^-1)?
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What is the purpose of SDS-page in electrophoresis?
What is the purpose of SDS-page in electrophoresis?
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What does Isoelectric focusing gel separate molecules according to?
What does Isoelectric focusing gel separate molecules according to?
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Why may bioactivity assays exhibit variability?
Why may bioactivity assays exhibit variability?
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What is the likely outcome of decreasing the liquid feed rate in spray drying?
What is the likely outcome of decreasing the liquid feed rate in spray drying?
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What is the effect of increasing the aspirator flow on cyclone efficiency for powder collection?
What is the effect of increasing the aspirator flow on cyclone efficiency for powder collection?
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What is the likely outcome of increasing the spray gas flow (atomizing pressure) in spray drying?
What is the likely outcome of increasing the spray gas flow (atomizing pressure) in spray drying?
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How does the solid concentration in the liquid affect the dry particles after evaporation of the liquid?
How does the solid concentration in the liquid affect the dry particles after evaporation of the liquid?
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What is the likely outcome to the residual water content in the powder using a drying gas with high temperature and low humidity at a high aspirator flow?
What is the likely outcome to the residual water content in the powder using a drying gas with high temperature and low humidity at a high aspirator flow?
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What does increasing aspirator flow lead to in terms of cyclone efficiency for powder collection?
What does increasing aspirator flow lead to in terms of cyclone efficiency for powder collection?
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What effect does decreasing liquid feed rate have on the drying process?
What effect does decreasing liquid feed rate have on the drying process?
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What is the likely outcome of increasing spray gas flow (atomizing pressure) on the fineness of the powder?
What is the likely outcome of increasing spray gas flow (atomizing pressure) on the fineness of the powder?
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What effect does a higher solid concentration in the liquid have on the size of dry particles after evaporation?
What effect does a higher solid concentration in the liquid have on the size of dry particles after evaporation?
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What is the purpose of spray freeze drying?
What is the purpose of spray freeze drying?
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What does Size Exclusion HPLC detect in proteins?
What does Size Exclusion HPLC detect in proteins?
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What does Circular Dichroism (CD) spectroscopy reveal about proteins?
What does Circular Dichroism (CD) spectroscopy reveal about proteins?
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What does Fourier transform infrared (FTIR) spectroscopy focus on in proteins?
What does Fourier transform infrared (FTIR) spectroscopy focus on in proteins?
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What does SDS-page electrophoresis separate molecules according to?
What does SDS-page electrophoresis separate molecules according to?
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What does isoelectric focusing gel electrophoresis separate molecules according to?
What does isoelectric focusing gel electrophoresis separate molecules according to?
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Why might bioactivity assays exhibit variability?
Why might bioactivity assays exhibit variability?
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Study Notes
Protein Stabilization and Formulation Techniques
- Proteins, including hGH, can aggregate due to hydrophobic interactions when unfolded.
- Zn binding sites and surfactants like polysorbate-20 can counteract hGH aggregation.
- Sugar and glycine stabilize proteins in liquid state by interacting with water.
- Amorphous sugar states can trap proteins, stabilizing the formulation through glass stabilization.
- Reconstituted hGH should be refrigerated to prevent concentration-induced aggregation.
- Freeze-drying involves creating a vacuum, freezing, and evaporating water to produce proteins in a dry form.
- Phosphate buffers can impact pH due to lower solubility at lower temperatures.
- Phosphate buffers can affect the stability of molecules during freezing.
- Low temperature and dehydration during freezing and drying can cause protein degradation.
- Spray drying is a one-step process to turn liquid into powder, used for producing inhalable insulin powder.
- Controlling factors for spray drying include inlet temperature, drying gas humidity, and aspirator air flow.
- High temperature and low humidity increase the dry capacity of gas, increasing liquid evaporation and drying rate.
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Description
Test your knowledge of protein stabilization and formulation techniques with this quiz. Learn about methods to prevent protein aggregation, the role of surfactants and sugars in stabilizing proteins, and the processes of freeze-drying and spray drying. Understand the impact of temperature, humidity, and buffers on protein stability and formulation.
