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TG/MS capillary interface

Applications to determination of residual moisture in BCG vaccine and other freeze-dried biological products

Journal of Thermal Analysis and Calorimetry
Authors: J. May, A. Del Grosso, R. Wheeler, and N. Etz

Abstract  

A TA Instruments Thermal Analysis System (TG) has been interfaced to the Hewlett Packard 5972 quadrupole mass spectrometer. An OSS-2 variable outlet splitter was plumbed between the TG and the mass spectrometer. This interface allows continuous monitoring of the ion intensities of mass peaksm/e=18 (water) andm/e=44 (carbon dioxide) used to elucidate the TG transitions attributable to residual moisture in freeze-dried biological products. Moisture specifications must be met in order to insure product stability throughout the approved shelf life. TG/MS results are discussed for BCG Vaccine, BCG Live (Intravesical) and U. S. Standard Antihemophilic Factor. Karl Fischer and TG/MS moisture results are compared.

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Thermogravimetry/mass spectrometry is used to identify TG transitions corresponding to loss of residual moisture in freeze-dried biological products with complex TG curves. While TG weight losses were recorded, ion intensities of mass peaksm/e=18 (water) andm/e=44 (carbon dioxide) were monitored continuously for Typhoid Vaccine U.S.P., Meningococcal Polysaccharide Vaccine Groups A and C Combined and Honey Bee Venom Allergenic Extract. MS ion intensities indicated the difference between evolution of residual moisture and moisture associated with product thermal decomposition. Residual moisture values calculated from TG weight losses indicated by mass spectral data agreed with Karl Fischer moisture data.

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Thermogravimetry and vapor pressure moisture

Applications to determination of residual moisture in BCG vaccine

Journal of Thermal Analysis and Calorimetry
Authors: J May, A Del Grosso, N Etz, R Wheeler, and L Rey

Abstract  

Thermogravimetry (TG), thermogravimetry/mass spectrometry (TG/MS), and loss-on-drying methodology are used to provide residual moisture results for freeze-dried biological products regulated by the US Food and Drug Administration. Residual moisture specifications must be met in order to ensure freeze-dried biological product potency and stability throughout the licensed product's shelf life. TG, TG/MS, loss-on-drying and vapor pressure moisture measurements are compared for a BCG Vaccine. Comparisons are made between residual moisture data for the freeze-dried cake and vapor pressure moisture determinations in the space above the freeze-dried cake in the final container. Vapor pressure moisture precision data is presented for α-interferon and BCG vaccine. Impact of residual moisture and vapor pressure moisture upon product stability is presented.

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Journal of Flow Chemistry
Authors: Mais J. Jebrail, Naila Assem, Jared M. Mudrik, Michael D.M. Dryden, Kaixiang Lin, Andrei K. Yudin, and Aaron R. Wheeler

Abstract

A microfluidic technique for combinatorial chemical synthesis of peptidomimetics has been developed. The new method is fast, automated and includes an integrated magnetic separation of inorganic catalysts from reaction products. This proof-of-concept study should lead to methods for generating libraries of compounds suitable for screening for bioactivity.

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