J 2024

Impact of secondary ice in a frozen NaCl freeze-concentrated solution on the extent of methylene blue aggregation

VESELÝ, Lukáš, Kamila ZAVACKA, Radim ŠTŮSEK, Martin OLBERT, Vilem NEDELA et. al.

Basic information

Original name

Impact of secondary ice in a frozen NaCl freeze-concentrated solution on the extent of methylene blue aggregation

Authors

VESELÝ, Lukáš (203 Czech Republic, belonging to the institution), Kamila ZAVACKA, Radim ŠTŮSEK (203 Czech Republic, belonging to the institution), Martin OLBERT, Vilem NEDELA, Evgenyi SHALAEV and Dominik HEGER (203 Czech Republic, guarantor, belonging to the institution)

Edition

International Journal of Pharmaceutics, AMSTERDAM, ELSEVIER, 2024, 0378-5173

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10403 Physical chemistry

Country of publisher

Netherlands

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 5.800 in 2022

Organization unit

Faculty of Science

UT WoS

001138921200001

Keywords in English

Freezing; Lyophilization; Methylene blue; Ice morphology; Secondary ice; Freeze-concentrated solution

Tags

Tags

International impact, Reviewed
Změněno: 22/3/2024 10:50, Mgr. Pavla Foltynová, Ph.D.

Abstract

V originále

Freezing and lyophilization have been utilized for decades to stabilize pharmaceutical and food products. Freezing a solution that contains dissolved salt and/or organic matter produces pure primary ice crystal grains separated by freeze-concentrated solutions (FCS). The microscopic size of the primary ice crystals depends on the cooling conditions and the concentration of the solutes. It is generally accepted that primary ice crystals size influences the rate of sublimation and also can impact physico-chemical behaviour of the species in the FCS. This article, however, presents a case where the secondary ice formed inside the FCS plays a critical role. We microscoped the structures of ice-cast FCS with an environmental scanning electron microscope and applied the aggregation-sensitive spectroscopic probe methylene blue to determine how the microstructure affects the mo-lecular arrangement. We show that slow cooling at-50 degrees C produces large salt crystals with a small specific surface, resulting in a high degree of molecular aggregation within the FCS. In contrast, fast liquid nitrogen cooling yields an ultrafine structure of salt crystals having a large specific surface area and, therefore, inducing smaller aggregation. The study highlights a critical role of secondary ice in solute aggregation and introduces methylene blue as a molecular probe to investigate freezing behaviour of aqueous systems with crystalline solute.

Links

MUNI/C/0104/2023, interní kód MU
Name: Studie změn kyselosti po zamrazení vybraných vícesytných anorganických solí a kyselin
Investor: Masaryk University, Study of freezing-induced acidty changes of various polyprotic anorganic acids and salts, Excellent diploma thesis