Determination of residual moisture in freeze-dried viral vaccines: Karl Fischer, gravimetric and thermogravimetric methodologies

May, Joan C.; Grim, Elizabeth C.; Wheeler, R.M.; West, Jerry

doi:10.1016/s0092-1157(82)80026-7

Cited by 52 publications

(30 citation statements)

References 4 publications

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“…52 For Karl Fisher titration, an Aqua Star Karl Fischer titrator (Model C3000, EM Sciences) equipped with a fritless cell was calibrated with Karl Fischer water standard (2-methoxy ethanol) and blanked with the addition of 1 ml anhydrous methanol (EM Sciences). Lyophilized samples were reconstituted with anhydrous methanol and added to the titrator.…”

Section: Moisture Analysismentioning

confidence: 99%

Development of formulations that enhance physical stability of viral vectors for gene therapy

2001

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Section: Moisture Analysismentioning

confidence: 99%

Development of formulations that enhance physical stability of viral vectors for gene therapy

2001

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“…Residual moisture of dried actin samples was measured using a Mettler DL37 coulometric moisture analyzer (Hightstown, NJ) with Hydranal reagents (Reidel de Haen, Seelze, Germany) as described previously. 26 …”

Section: Moisture Analysismentioning

confidence: 99%

Optimization of Storage Stability of Lyophilized Actin Using Combinations of Disaccharides and Dextran

Allison

Manning

Randolph

et al. 2000

Journal of Pharmaceutical Sciences

123

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“…The cells were then lyophilized, according to procedures that have been described in detail (12). Samples prepared in this manner consistently exhibit moisture contents of 1-3%, as measured by the Karl Fischer method (13). At day 10 (12) by centrifugation at 1800 x g, using a Cobe automatic cell washer.…”

Section: Methodsmentioning

confidence: 99%

Preservation of metabolic activity in lyophilized human erythrocytes.

Goodrich¹,

Sowemimo-Coker²,

Zerez³

et al. 1992

Proc. Natl. Acad. Sci. U.S.A.

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Normal human erythrocytes (RBC) were freeze-dried under conditions that caused minimal modification in normal RBC metabolic activities. Because of the known effects of long-term storage on metabolic activities, we studied the effects ofour Iyophilization process on RBC metabolism. Of all the metabolic enzymes studied, only triosephosphate isomerase (D-glyceraldehyde-3-phosphate ketol-isomerase, EC 5.3.1.1), enolase (2-phospho-D-glyceratehydro-lyase, EC 4.2.1.11), and pyruvate kinase (ATP:pyruvate 02-phosphotransferase, EC 2.7.1.40) were decreased when compared with fresh control nonlyophilized RBC. The activities of these enzymes did not differ significantly from those of blood bank RBC. Concentrations of high-energy intermediates, ATP, and 2,3-diphosphoglycerate, along with lactate and ATP production were decreased in Iyophilized RBC. No enzymes of the pentose phosphate shunt were altered during Iyophilization. In addition, our data show that Iyophilized RBC possess an intact capacity to (i) synthesize adenine nucleotides and (ii) reduce MetHb to Hb and, thus, maintain the Hb in a functional physiologic state similar to fresh nonlyophilized RBC. The present study demonstrates the possibility of Iyophilizing RBC in a manner that maintains normal metabolic and enzymatic function upon rehydration.Maintenance of the metabolic functions of human erythrocytes (RBC) during long-term storage is crucial to their in vivo survival and physiologic functions. Several investigators have addressed this problem and have found that certain storage conditions can preserve the metabolic functions of RBC (1-4). Some of these storage conditions involve refrigeration in liquid media (1, 2), which allows for a 35-to 42-day shelf life, or frozen storage at -80'C, which permits longterm storage (up to 10 yr) but requires maintenance of low temperature (3, 4). The ability to freeze-dry RBC would eliminate this need for low storage temperatures. A successful process would require that damage to the cells normally induced by drying be avoided. Cells treated in this manner must retain normal cytoskeletal, metabolic, and oxygentransporting functions. In this paper we examined the effects of freeze-drying on one of these characteristics-namely, metabolic function. Several previous studies have shown promise in this regard by demonstrating that certain protectants are effective in preserving the enzyme activities and functions of dry biological specimens (5). Until this time, however, no comparable demonstration has been provided due to limitations of available methods for protecting cells from damage during drying.Normal adult human RBC generate energy almost exclusively through the metabolism of glucose primarily via the Embden-Meyerhof pathway and the pentose phosphate shunt (PPS) (Fig. 1). These pathways produce the cellular energy crucial to RBC survival and maintenance of proper cell functions (6, 7). In particular, two products of glycolysis, ATP and 2,3-diphosphoglycerate (2,3-DPG) act to regulate the oxygen affinity of Hb. Th...

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Determination of residual moisture in freeze-dried viral vaccines: Karl Fischer, gravimetric and thermogravimetric methodologies

Cited by 52 publications

References 4 publications

Development of formulations that enhance physical stability of viral vectors for gene therapy

Development of formulations that enhance physical stability of viral vectors for gene therapy

Optimization of Storage Stability of Lyophilized Actin Using Combinations of Disaccharides and Dextran

Preservation of metabolic activity in lyophilized human erythrocytes.

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