Related Experiment Video
Updated: May 29, 2026

Comparative Analysis of Human Growth Hormone in Serum Using SPRi, Nano-SPRi and ELISA Assays
Published on: January 7, 2016
Stability of human growth hormone in supercritical carbon dioxide
Catherine A Kelly1, Steven M Howdle, Andrew Naylor
1School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK.
Abstract:
The instability of human growth hormone (hGH) to temperature and interfaces makes its formulation into injectable, sustained-release drug delivery systems challenging. A novel method of encapsulating hGH in polymeric microparticles has been developed using supercritical CO(2) (scCO(2)) technology, but there is limited understanding of the stability of hGH within this system. The aim of this study was to evaluate the stability of hGH in scCO(2) processing. The integrity of the protein was assessed following exposure to scCO(2) using a range of different analytical techniques. Mass spectrometry showed that no peptide cleavage occurred as a result of processing or exposure to scCO(2). Size-exclusion chromatography detected formation of aggregates at high temperatures, but not as a result of the encapsulation process. Reverse-phase chromatography demonstrated that the production of deamidation products occurred as a function of temperature, but only at temperatures higher than those used for the encapsulation process. Circular dichroism and infrared spectroscopy demonstrated that the use of scCO(2) was not detrimental to the secondary molecular structure of hGH. Together, these results show that the structural integrity of hGH is unaffected by scCO(2) processing and that hGH can be successfully encapsulated in polymer microparticles using this technique.
More Related Videos
Related Concept Videos
Supercritical Fluid Chromatography
SFC utilizes a supercritical fluid mobile phase,...
Phase Diagrams
Carbon Dioxide Transport in the Blood
Forms of CO2 Transport
1. Dissolved in plasma: A small percentage (7-10%) of CO2 is transported and dissolved directly in the plasma.
2. Carbaminohemoglobin: Just over 20% of CO2 is chemically bound to...
Drug Product Stability
Pharmaceutical Alternatives: Stability-Related Therapeutic Nonequivalence
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...

