Effect of Collapse on the Stability of Freeze-Dried Recombinant Factor VIII and α-amylase

Wang, D.Q.; Hey, Jeffery M; Nail, Steven L.

doi:10.1002/jps.20065

Cited by 96 publications

(52 citation statements)

References 11 publications

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“…Glycine, PVP, and glycerol also increased ZSA activity. Glycine is related to a long-term stability of a-amylases (Wang et al, 2004). Glycerol did not increase activity of aamylase from Bacillus licheniformis (Esteve-Romero et al, 1996).…”

Section: Discussionmentioning

confidence: 99%

Structure and enzyme properties of Zabrotes subfasciatus α‐amylase

Pelegrini

Murad

Grossi-de-Sá

et al. 2006

Arch Insect Biochem Physiol

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Digestive alpha-amylases play an essential role in insect carbohydrate metabolism. These enzymes belong to an endo-type group. They catalyse starch hydrolysis, and are involved in energy production. Larvae of Zabrotes subfasciatus, the Mexican bean weevil, are able to infest stored common beans Phaseolus vulgaris, causing severe crop losses in Latin America and Africa. Their alpha-amylase (ZSA) is a well-studied but not completely understood enzyme, having specific characteristics when compared to other insect alpha-amylases. This report provides more knowledge about its chemical nature, including a description of its optimum pH (6.0 to 7.0) and temperature (20-30 degrees C). Furthermore, ion effects on ZSA activity were also determined, showing that three divalent ions (Mn2+, Ca2+, and Ba2+) were able to enhance starch hydrolysis. Fe2+ appeared to decrease alpha-amylase activity by half. ZSA kinetic parameters were also determined and compared to other insect alpha-amylases. A three-dimensional model is proposed in order to indicate probable residues involved in catalysis (Asp204, Glu240, and Asp305) as well other important residues related to starch binding (His118, Ala206, Lys207, and His304).

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Section: Discussionmentioning

confidence: 99%

Structure and enzyme properties of Zabrotes subfasciatus α‐amylase

Pelegrini

Murad

Grossi-de-Sá

et al. 2006

Arch Insect Biochem Physiol

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“…Similar results were seen in a recent study where longterm stability of recombinant Factor VIII and aamylase was compared in lyophilized formulations with collapsed and retained cake structure. 22 Moreover, no loss in activity was observed even in the absence of a lyoprotectant indicating, primary-drying was not a critical step for this protein. I and II indicate shelf and condenser temperature settings during primary and secondary-drying, respectively.…”

Section: Primary-drying Studiesmentioning

confidence: 98%

“…These results are consistent with another reported study on the effect of collapse. 22 However, collapse does affect the product appearance, and it is frequently undesirable simply due to unacceptable appearance, longer drying times, increased crystallization tendency, 23 and possible effect on reconstitution time. Therefore, to prevent collapse, one frequently needs to freeze-dry at low temperatures, making primary-drying very slow due to the low vapor pressure of ice at low temperatures.…”

Section: Secondary-drying Studiesmentioning

confidence: 99%

Investigation of Drying Stresses on Proteins during Lyophilization: Differentiation between Primary and Secondary-Drying Stresses on Lactate Dehydrogenase Using a Humidity Controlled Mini Freeze-Dryer

Luthra

Obert

Kalonia

et al. 2007

Journal of Pharmaceutical Sciences

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“…The goal is to avoid product degradation, in particular in case of pharmaceutical and biopharmaceutical formulations, and also the collapse (or the shrinkage) of the dried product (the so called "cake") in case aqueous solutions containing amorphous products are processed, as this threaten the elegance of the cake and the product could show a higher reconstitution time and a higher amount of residual humidity. In case aqueous solutions containing crystalline products are processed, the limit value is the eutectic temperature, in order to prevent product melting [6][7][8][9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Computer-Aided Framework for the Design of Freeze-Drying Cycles: Optimization of the Operating Conditions of the Primary Drying Stage

Fissore

Pisano

2015

Processes

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This paper deals with the freeze-drying process and, in particular, with the optimization of the operating conditions of the primary drying stage. When designing a freeze-drying cycle, process control aims at obtaining the values of the operating conditions (temperature of the heating fluid and pressure in the drying chamber) resulting in a product temperature lower than the limit value of the product, and in the shortest drying time. This is particularly challenging, mainly due to the intrinsic nonlinearity of the system. In this framework, deep process knowledge is required for deriving a suitable process dynamic model that can be used to calculate the design space for the primary drying stage. The design space can then be used to properly design (and optimize) the process, preserving product quality. The case of a product whose dried layer resistance, one of the key model parameters, is affected by the operating conditions is addressed in this paper, and a simple and effective method to calculate the design space in this case is presented and discussed.

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Effect of Collapse on the Stability of Freeze-Dried Recombinant Factor VIII and α-amylase

Cited by 96 publications

References 11 publications

Structure and enzyme properties of Zabrotes subfasciatus α‐amylase

Structure and enzyme properties of Zabrotes subfasciatus α‐amylase

Investigation of Drying Stresses on Proteins during Lyophilization: Differentiation between Primary and Secondary-Drying Stresses on Lactate Dehydrogenase Using a Humidity Controlled Mini Freeze-Dryer

Computer-Aided Framework for the Design of Freeze-Drying Cycles: Optimization of the Operating Conditions of the Primary Drying Stage

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