OPTIMAL CONTROL OF THE PRIMARY AND SECONDARY DRYING STAGES OF BULK SOLUTION FREEZE DRYING IN TRAYS

Objective: Development of a lyophilized injectable dosage form LCS-1208, an original antitumor drug based on an indolocarbazole derivative. Methods: The prepared solution of the injectable dosage form LCS-1208 is transferred to sterilizing filtration, which is carried out under vacuum on a «Stericup» filter unit with a filter pore size of 0.22 μm. The sterile solution of the injectable dosage form LCS-1208 is poured into sterile vials using a dispenser and lyophilized in a freeze-drying chamber. At the end of drying, the preparation is corked in the chamber of a sublimation unit using a hydraulic device and transferred to crimping with aluminum caps using a seaming machine. Quantitative determination of the drug content was determined by spectrophotometry using a standard sample at λ = 320±2 nm. The pH was determined by potentiometry. Results: A freeze-drying regimen for the injectable dosage form LCS-1208 has been developed. The required solution freezing temperature was established taking into account the presence of 2 eutectic zones: a solution of LCS-1208 in DMSO (-35 ÷-32) °С, an aqueous solution of Kollidon 17PF (-10 ÷-8) °С. As a result of a series of experiments, the optimal lyophilization regime was chosen that does not require preliminary freezing in a low-temperature chamber, with freezing on the shelves of freeze-drying at a temperature of-47 °C without their preliminary cooling. The most acceptable vial filling volume was determined, amounting to 3 ml, and the rate of temperature rise during secondary drying of the preparation was justified. When using the developed regime of lyophilization of the LCS-1208 solution, it was shown that it can be sublimated while preserving the initial qualitative and quantitative characteristics. Conclusion: In this article, using the example of creating a lyophilized injectable dosage form LCS-1208 (the original antitumor drug from the indolocarbazole group), the main problems that arose during the lyophilization of the selected composition of the model solution, as well as ways to improve the process.

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Fluorescence Properties of the Air- and Freeze-Drying Treatment on Size-Fractioned Sediment Organic Matter

Applied Sciences ◽

10.3390/app11178220 ◽

2021 ◽

Vol 11 (17) ◽

pp. 8220

Author(s):

Cheng-Wen Chuang ◽

Wei-Shiang Huang ◽

Yung-Yu Liu ◽

Chi-Ying Hsieh ◽

Ting-Chien Chen

Keyword(s):

Molecular Weight ◽

Organic Matter ◽

Organic Carbon ◽

Freeze Drying ◽

Biological Activities ◽

Sediment Organic Matter ◽

Bulk Solution ◽

Similar Distribution ◽

Organic Mixture ◽

Freeze Dried

Sediment humic substance (SHS) is a highly heterogeneous and complex organic mixture with a broad molecular weight range. It is the significant component that associates distribution, transport, and biotoxicity of pollutants in a river environment. Air- and freeze-drying sediment pre-treatment may cause different biological activity and may result in different chemical quantities and sediment organic matter. This study collected sediments that received livestock wastewater discharge. The sediments were air- (AD) and freeze-dried (FD). The dried sediment organic matter was extracted with an alkaline solution and separated into three size-fractioned SHS samples. Size-fractioning is an effective method used to differentiate materials, on a molecular level. The bulk solution (<0.45 μm) was designated as BHS, and size-fractioned solutions were identified as LHS (<1 kDa), MHS (1–10 kDa), and HHS (10 kDa-0.45 μm). The AD SHS had a lower dissolved organic carbon (DOC) concentration than the FD SHS for the bulk and individual size-fractioned SHS, but the AD and FD SHS had a similar distribution of organic carbon in the size-fractioned SHS. The AD SHS had higher aromaticity (SUVA254) and an extent of humification (HIX) than the FD SHS. In addition, the high molecular weight SHS (HHS) had a higher SUVA254 but lower HIX than the MHS and LHS. The HHS had significantly lower fulvic acid but had higher humic acid-like substances than the MHS and LHS. This is possibly the reason the LHS had a higher humification degree but lower aromaticity than HHS. The size-fractioned SHS and optical indicators distinguished the difference between the chemical properties when air- or freeze-dried, due to the different degree of biological activities.

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The Freeze-Drying of Foods—The Characteristic of the Process Course and the Effect of Its Parameters on the Physical Properties of Food Materials

Foods ◽

10.3390/foods9101488 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1488 ◽

Cited By ~ 1

Author(s):

Dorota Nowak ◽

Ewa Jakubczyk

Keyword(s):

Mechanical Properties ◽

Physical Properties ◽

Structural Properties ◽

Freeze Drying ◽

Process Conditions ◽

Drying Process ◽

High Quality ◽

Freeze Dried ◽

Secondary Drying ◽

Selection Of

Freeze-drying, also known as lyophilization, is a process in which water in the form of ice under low pressure is removed from a material by sublimation. This process has found many applications for the production of high quality food and pharmaceuticals. The main steps of the freeze-drying process, such as the freezing of the product and primary and secondary drying, are described in this paper. The problems and mechanisms of each step of the freeze-drying process are also analyzed. The methods necessary for the selection of the primary and secondary end processes are characterized. The review contains a description of the effects of process conditions and the selected physical properties of freeze-dried materials, such as structural properties (shrinkage and density porosity), color, and texture. The study shows that little attention is given to the mechanical properties and texture of freeze-dried materials obtained from different conditions of the lyophilization process.

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