Freeze-Drying of Pharmaceutical Products: Research and Development Needs

Sadıkoğlu, Hasan; Özdemir, Mustafa; Şeker, Mine Gül

doi:10.1080/07373930600734018

Cited by 80 publications

(48 citation statements)

References 39 publications

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“…6,7 Searles et al 86 pointed out that the temperature of ice nucleation fixed the final ice morphology of the frozen material (ice and cryo-concentrated phase), and it was strongly correlated to the rate of the primary drying step. Sadikoglu et al 87 pointed out that the ice crystals formed during the freezing stage determined the size and shape of pores, the pore size distribution, and the pore connectivity of the porous matrix, thus affecting heat and mass transfer during the primary and secondary drying stages. Recently, Nakagawa et al, 88 using a mathematical model for the freezing process of a standard pharmaceutical formulation (mannitol and bovine serum albumin-based), confirmed that the mass transfer parameters in freeze drying were strongly dependant on the morphological parameters of the frozen phase and, consequently, on the nucleation temperatures.…”

Section: Role Of Ice Morphology In Freeze Drying Of Pharmaceutical Fomentioning

confidence: 99%

Ice Morphology: Fundamentals and Technological Applications in Foods

2009

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Freezing is the process of ice crystallization from supercooled water. Ice crystal morphology plays an important role in the textural and physical properties of frozen and frozen-thawed foods and in processes such as freeze drying, freeze concentration, and freeze texturization. Size and location of ice crystals are key in the quality of thawed tissue products. In ice cream, smaller ice crystals are preferred because large crystals results in an icy texture. In freeze drying, ice morphology influences the rate of sublimation and several morphological characteristics of the freeze-dried matrix as well as the biological activity of components (e.g., in pharmaceuticals). In freeze concentration, ice morphology influences the efficiency of separation of ice crystals from the concentrated solution. The cooling rate has been the most common variable controlling ice morphology in frozen and partly frozen systems. However, several new approaches show promise in controlling nucleation (consequently, ice morphology), among them are the use of ice nucleation agents, antifreeze proteins, ultrasound, and high pressure. This paper summarizes the fundamentals of freezing, methods of observation and measurement of ice morphology, and the role of ice morphology in technological applications.

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Section: Role Of Ice Morphology In Freeze Drying Of Pharmaceutical Fomentioning

confidence: 99%

Ice Morphology: Fundamentals and Technological Applications in Foods

2009

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“…The benefits that can be achieved by an optimal monitoring and control policy in a freeze-drying process have been recently discussed. 16 Actually, poor process control still characterizes even the most advanced industrial freeze-dryers: regulatory guidance, up to now, imposed to operate the manufacturing process in open loop, so that only an activity of monitoring was allowed during production. Furthermore, it was not possible the reliable in-line measurement, in a production process, of the parameters of interest, namely the product temperature and the amount of residual water.…”

Section: Introductionmentioning

confidence: 99%

In-Line Optimization and Control of an Industrial Freeze-Drying Process for Pharmaceuticals

Pisano

Fissore

Velardi

2010

Journal of Pharmaceutical Sciences

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“…An increased surface area correlates with decreased dried product stability for some proteins (Santana et al, 2010). Freezing by immersing a glass tube into liquid nitrogen can result in increased protein aggregation (Santana et al, 2010) or decreased enzymatic activity (Sadikoglu et al, 2006) when compared with freezer-cooled samples.…”

Section: Freeze Dryingmentioning

confidence: 99%

Drying of α-amylase by spray drying and freeze-drying - a comparative study

Jesus

Filho

2014

Braz. J. Chem. Eng.

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-This study is aimed at comparing two traditional methods of drying of enzymes and at verifying the efficiency of each one and their advantages and disadvantages. The experiments were performed with a laboratory spray dryer and freeze-dryer using α-amylase as the model enzyme. An experimental design in star revealed that spray drying is mainly influenced by the inlet air temperature and feed flow rate, which were considered to be the main factors influencing the enzymatic activity and water activity; the long period of material exposure to high temperatures causes a partial activity loss. In the experiments of freeze drying, three methods of freezing were used (freezer, acetone and dry ice, and liquid nitrogen) and samples subsequently freeze-dried for times ranging between 0-24 hours. The product obtained from the two techniques showed high enzymatic activity and low water activity. For the drying of heat-resistant enzymes, in which the product to be obtained does not have high added value, spray drying may be more economically viable because, in the freeze drying process, the process time can be considered as a limiting factor when choosing a technique.

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Freeze-Drying of Pharmaceutical Products: Research and Development Needs

Cited by 80 publications

References 39 publications

Ice Morphology: Fundamentals and Technological Applications in Foods

Ice Morphology: Fundamentals and Technological Applications in Foods

In-Line Optimization and Control of an Industrial Freeze-Drying Process for Pharmaceuticals

Drying of α-amylase by spray drying and freeze-drying - a comparative study

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