2017
Comparing the acidities of aqueous, frozen, and freeze-dried phosphate buffers: Is there a "pH memory" effect?
VETRÁKOVÁ, Ľubica, Vít VYKOUKAL a Dominik HEGERZákladní údaje
Originální název
Comparing the acidities of aqueous, frozen, and freeze-dried phosphate buffers: Is there a "pH memory" effect?
Autoři
VETRÁKOVÁ, Ľubica (703 Slovensko, domácí), Vít VYKOUKAL (203 Česká republika, domácí) a Dominik HEGER (203 Česká republika, garant, domácí)
Vydání
International Journal of Pharmaceutics, AMSTERDAM, ELSEVIER SCIENCE BV, 2017, 0378-5173
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
30104 Pharmacology and pharmacy
Stát vydavatele
Nizozemské království
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 3.862
Kód RIV
RIV/00216224:14310/17:00100008
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000410643800034
Klíčová slova anglicky
Protein cryopreservation; Freezing; Lyophilization; pH shift; Freezing stress; pH memory; Formulation buffers
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 30. 3. 2018 15:23, Ing. Nicole Zrilić
Anotace
V originále
The concept of "pH memory" has been established in the literature for the correlation between the pH of a pre-lyophilization solution and the ionization state of freeze-dried powder (lyophile). In this paper, the concept of "pH memory" is explored for the system of an aqueous solution, a frozen solution, and a lyophile. Sodium and potassium phosphate buffers in the pH range of 5-9 were frozen and lyophilized with sulfonephthalein indicators as acidity probes, and their Hammett acidity functions were compared to the initial pH of the aqueous solution. The results show that the acidities of the lyophiles are somewhat changed compared to the initial pHs, but the acidities in the frozen state differ more substantially. The Hammett acidity functions of the frozen buffers were found to be markedly dissimilar from the initial pH, especially in the sodium phosphate frozen at 233 K, where an increase in the initial pH led to a decrease in the Hammett acidity function of the frozen state at a certain pH range. The large acidification observed after freezing the sodium phosphate buffer was not detected in the lyophiles after the sample had been dried; the phenomenon is explained considering the formed crystals analyzed by X-ray powder diffraction. The results suggest that monitoring the final acidity of a lyophile is not sufficient to predict all the acidity changes throughout the whole lyophilization process. The importance of well-controlled freezing and lyophilization conditions follows from the results of the research.
Návaznosti
ED2.1.00/19.0382, projekt VaV |
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LM2011028, projekt VaV |
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LO1214, projekt VaV |
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