THE STABILITY OF PLANE SUBLIMATION AND A MODEL OF ZONE SUBLIMATION IN FREEZE-DRYING OF POROUS BODIES

Liposomes have been utilized as a drug delivery system to increase the bioavailability of drugs and to control the rate of drug release at the target site of action. However, the occurrence of self-aggregation, coalescence, flocculation and the precipitation of aqueous liposomes during formulation or storage can cause degradation of the vesicle structure, leading to the decomposition of liposomes. To increase the stability of liposomes, post-processing techniques have been applied as an additional process to liposomes after formulation to remove water and generate dry liposome particles with a higher stability and greater accessibility for drug administration in comparison with aqueous liposomes. This review covers the effect of these techniques including freeze drying, spray drying and spray freeze drying on the stability, physicochemical properties and drug encapsulation efficiency of dry liposomes. The parameters affecting the properties of liposomes during the drying process are also highlighted in this review. In addition, the impact of using a protective agent to overcome such limitations of each process is thoroughly discussed through various studies.

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Stability of pseudorabies virus during freeze-drying and storage: effect of suspending media

Journal of Clinical Microbiology ◽

10.1128/jcm.4.1.1-5.1976 ◽

1976 ◽

Vol 4 (1) ◽

pp. 1-5

Author(s):

E M Scott ◽

W Woodside

Keyword(s):

Freeze Drying ◽

Pseudorabies Virus ◽

Storage Effect ◽

Drying Process ◽

Sodium Glutamate ◽

Degree Of Protection ◽

The Stability ◽

Subsequent Storage ◽

And Storage ◽

Lactalbumin Hydrolysate

The effect of suspending media on the stability of pseudorabies virus upon freeze-drying and subsequent storage was studied. A variety of media was tested, including: sodium glutamate; sucrose; lactose; lactalbumin hydrolysate; peptone; a combination of sucrose, dextran, and glutamate; and various combinations of sucrose, glutamate, and potassium phosphates. Suspending media containing glutamate, either alone or in combination with sucrose and either dextran or phosphates, afforded the greatest degree of protection during the freeze-drying process and upon storage. Some possible functions of these additives in preventing injury to the virus during freezing and drying have been suggested.

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Study on Colour Stability and Microencapsulation of Anthocyanin Pigment Extracted from Dragon Fruit Peel by Spray and Freeze Drying

Proceedings International ◽

10.33263/proceedings21.047047 ◽

2020 ◽

Vol 2 (1) ◽

pp. 47

Keyword(s):

Freeze Drying ◽

Anthocyanin Content ◽

Microwave Assisted Extraction ◽

Fruit Peel ◽

Total Anthocyanin ◽

Natural Colorant ◽

Microwave Assisted ◽

Assisted Extraction ◽

Dragon Fruit ◽

The Stability

Dragon fruit is a popular fruit grown in Malaysia. It is well known for the rich nutrient contents, and it is commercially available worldwide. It is rich in anthocyanins and antioxidants. Dragon fruit is also an essential source of betacyanin, which serves as a red/purple pigment with antioxidative properties. The objective of the present work is to study the stability of natural colorant from dragon fruit peel. The crushed peel and water were taken in the ratio of 1:10 and was subjected to seven different types of extraction techniques such as microwave-assisted extraction, ohmic heating, ultrahigh-pressure homogenization, sonicator, supercritical fluid extraction, aqueous extraction, Soxhlet extraction. Out of the microwave-assisted extraction had the most Anthocyanin content, and it was used for further studies. The selected extract was filtered, and the stability of anthocyanin was examined at varying pH (2…10) and temperature (60…100⁰C). In addition to this, thermal stability (80…100 ⁰C for 150 min) was checked at a deferent time interval (80 to 100⁰C…150 min.). The microwave extract was used for the encapsulation process using maltodextrin, and soy protein isolate as carrier material with 1:4, 1:5 core to wall ratio by spray drying and freeze-drying techniques. The quality analysis, such as total anthocyanin content, encapsulation efficiency, color, water activity, bulk density, solubility, and moisture content, were analyzed of microencapsulated anthocyanin extract. This result showed that encapsulated dragon fruit peel (pitaya) powder could be used as a natural colorant in food applications.

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Establishment of an Experimental Procedure for Preparing Trial Serum Samples for the Specific Serodiagnosis of Toxocara canis for External Quality Assessment Schemes

Journal of Parasitology Research ◽

10.1155/2020/6842975 ◽

2020 ◽

Vol 2020 ◽

pp. 1-7

Author(s):

Quang Huy Vu ◽

Diep Tuan Tran ◽

Phu Manh Sieu Tran ◽

Van Chuong Le ◽

Thi Diem Phuc Huynh ◽

...

Keyword(s):

Quality Assessment ◽

Western Blotting ◽

Freeze Drying ◽

External Quality Assessment ◽

Toxocara Canis ◽

Serum Samples ◽

External Quality ◽

Experimental Procedure ◽

The Stability ◽

Anti Hiv

Background. External quality assessment (EQA) provides evidence of reliable, accurate, and precise results for customers using the diagnostic test for Toxocara canis. Objective. To establish a procedure for producing standard Toxocara canis serum samples for serodiagnostic testing in EQA. Methods. The collected serum samples to contain anti-Toxocara canis antibodies were screened by ELISA and confirmed by Western blotting. These samples were found to be negative for other helminth antibodies, anti-HIV-1 and -2 antibodies, anti-HCV antibodies, and antibodies to HBs antigen. The sera were divided, processed by both freeze-drying and freezing methods, and then stored. The stability and homogeneity of the samples were evaluated after 7 days, 1 month, 3 months, and 6 months. An F-test and a T-test were applied to evaluate their homogeneity and stability. Results. Among eleven samples positive by ELISA, ten of them were confirmed via Western blotting by positive reaction with 5 specific Toxocara canis bands. Two lots of trial standard sera containing specific anti-Toxocara canis antibodies were successfully produced. Lot DK had a concentration of 31.01±1.1 NovaTec Units (NTU), and Lot DL had a concentration of 27.18±0.9 NTU. After storage at -80°C, the samples prepared by the freeze-drying method were stable for at least 3 months, and the samples prepared by the freezing method were stable for 6 months (p>0.05). Samples produced by both methods were stable for 7 days at 30°C (p>0.05). Conclusion. Specific serodiagnosis samples of anti-Toxocara canis antibodies for EQA could be produced that possessed homogeneity and stability lasting for 3 months and 6 months by the freeze-drying and freezing methods, respectively. At 30°C, the samples produced by both methods were stable for 7 days, suitable for delivery to remote laboratories.

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Drying Technologies for the Stability and Bioavailability of Biopharmaceuticals

Pharmaceutics ◽

10.3390/pharmaceutics10030131 ◽

2018 ◽

Vol 10 (3) ◽

pp. 131 ◽

Cited By ~ 32

Author(s):

Fakhrossadat Emami ◽

Alireza Vatanara ◽

Eun Park ◽

Dong Na

Keyword(s):

Freeze Drying ◽

Therapeutic Proteins ◽

Drying Methods ◽

Solid Dosage Forms ◽

Solid Dosage ◽

Supercritical Fluid Drying ◽

Protein Properties ◽

Critical Process Parameters ◽

The Stability ◽

Critical Process

Solid dosage forms of biopharmaceuticals such as therapeutic proteins could provide enhanced bioavailability, improved storage stability, as well as expanded alternatives to parenteral administration. Although numerous drying methods have been used for preparing dried protein powders, choosing a suitable drying technique remains a challenge. In this review, the most frequent drying methods, such as freeze drying, spray drying, spray freeze drying, and supercritical fluid drying, for improving the stability and bioavailability of therapeutic proteins, are discussed. These technologies can prepare protein formulations for different applications as they produce particles with different sizes and morphologies. Proper drying methods are chosen, and the critical process parameters are optimized based on the proposed route of drug administration and the required pharmacokinetics. In an optimized drying procedure, the screening of formulations according to their protein properties is performed to prepare a stable protein formulation for various delivery systems, including pulmonary, nasal, and sustained-release applications.

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Studies on the stability of creatine kinase isozymes

Biochemistry and Cell Biology ◽

10.1139/o02-171 ◽

2003 ◽

Vol 81 (1) ◽

pp. 9-16 ◽

Cited By ~ 3

Author(s):

Zhi Guo ◽

Zheng Wang ◽

Xicheng Wang

Keyword(s):

Differential Scanning Calorimetry ◽

Creatine Kinase ◽

Freeze Drying ◽

Biological Significance ◽

Subunit Interactions ◽

Scanning Calorimetry ◽

Gradient Gel Electrophoresis ◽

The Stability ◽

Creatine Kinase Isozymes ◽

Monomer Form

Research on the stabilizing properties of creatine kinase isozymes CK-BB, CK-MB, and CK-MM showed that minor alteration of their sequence and structure influenced their stability significantly. An analysis of the stability of the isozymes in storage after freeze drying indicates that creatine kinase isozymes are all in monomer form because of the loss of subunit interactions. Freeze-drying leads to the oxidization of CK-BB and rearrangement of CK-MB. There are also differences in the unfolding of the isozymes in urea. CK-BB and CK-MB are unfolded in lower urea concentrations than CK-MM. Differences in the thermal unfolding were also examined by differential scanning calorimetry. This paper discusses the potential biological significance of these results.Key words: creatine kinase isozymes, fluorescence, circular dichroism, differential scanning calorimetry, urea gradient gel electrophoresis.

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The effect of excipients on the stability and aerosol performance of salmon calcitonin dry powder inhalers prepared via the spray freeze drying process

Acta Pharmaceutica ◽

10.1515/acph-2016-0012 ◽

2016 ◽

Vol 66 (2) ◽

pp. 207-218 ◽

Cited By ~ 8

Author(s):

Narges Poursina ◽

Alireza Vatanara ◽

Mohammad Reza Rouini ◽

Kambiz Gilani ◽

Abdolhossein Rouholamini Najafabadi

Keyword(s):

Salmon Calcitonin ◽

Freeze Drying ◽

Tween 80 ◽

Drying Process ◽

Dry Powders ◽

Aerosol Performance ◽

Inhalation Delivery ◽

Spray Freeze Drying ◽

The Stability ◽

Structurally Stable

Abstract Spray freeze drying was developed to produce dry powders suitable for applications such as inhalation delivery. In the current study, the spray freeze drying technique was employed to produce inhalable salmon calcitonin microparticles. Effects of the carrier type, concentration of hydroxyl propyl-β-cyclodextrin and the presence of Tween 80 on the chemical and structural stability, as well as on the aerosol performance of the particles were investigated. The results indicated that hydroxyl propyl-β-cyclodextrin had the most important effect on the chemical stability of the powder and strongly increased its stability by increasing its concentration in the formulation. Chemically stable formulations (over 90 % recovery) were selected for further examinations. Fluorescence spectroscopy and circular dichroism suggested that the formulations were structurally stable. Aerosol performance showed that the Tween-free powders produced higher fine particle fraction values than the formulations containing Tween (53.7 vs. 41.92 % for trehalose content and 52.85 vs. 43.06 % for maltose content).

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Shelf-Life Evaluation and Lyophilization of PBCA-Based Polymeric Microbubbles

Pharmaceutics ◽

10.3390/pharmaceutics11090433 ◽

2019 ◽

Vol 11 (9) ◽

pp. 433 ◽

Cited By ~ 5

Author(s):

Tarun Ojha ◽

Vertika Pathak ◽

Natascha Drude ◽

Marek Weiler ◽

Dirk Rommel ◽

...

Keyword(s):

Shelf Life ◽

Rhodamine B ◽

Freeze Drying ◽

Pharmaceutical Products ◽

Acoustic Properties ◽

Signal Generation ◽

Freeze Dried ◽

Different Temperatures ◽

The Stability ◽

Commercial Platform

Poly(n-butyl cyanoacrylate) microbubbles (PBCA-MB) are extensively employed for functional and molecular ultrasound (US) imaging, as well as for US-mediated drug delivery. To facilitate the use of PBCA-MB as a commercial platform for biomedical applications, it is important to systematically study and improve their stability and shelf-life. In this context, lyophilization (freeze drying) is widely used to increase shelf-life and promote product development. Here, we set out to analyze the stability of standard and rhodamine-B loaded PBCA-MB at three different temperatures (4 °C, 25 °C, and 37 °C), for a period of time of up to 20 weeks. In addition, using sucrose, glucose, polyvinylpyrrolidone (PVP), and polyethylene glycol (PEG) as cryoprotectants, we investigated if PBCA-MB can be lyophilized without affecting their size, concentration, US signal generation properties, and dye retention. Stability assessment showed that PBCA-MB remain largely intact for three and four weeks at 4 °C and 25 °C, respectively, while they disintegrate within one to two weeks at 37 °C, thereby compromising their acoustic properties. Lyophilization analyses demonstrated that PBCA-MB can be efficiently freeze-dried with 5% sucrose and 5% PVP, without changing their size, concentration, and US signal generation properties. Experiments involving rhodamine-B loaded MB indicated that significant dye leakage from the polymeric shell takes place within two to four weeks in case of non-lyophilized PBCA-MB. Lyophilization of rhodamine-loaded PBCA-MB with sucrose and PVP showed that the presence of the dye does not affect the efficiency of freeze-drying, and that the dye is efficiently retained upon MB lyophilization. These findings contribute to the development of PBCA-MB as pharmaceutical products for preclinical and clinical applications.

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PREPARATION OF CHITOSAN-TPP NANOPARTICLES: THE INFLUENCE OF CHITOSAN POLYMERIC PROPERTIES AND FORMULATION VARIABLES

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2018v10i5.26375 ◽

2018 ◽

Vol 10 (5) ◽

pp. 60 ◽

Cited By ~ 7

Author(s):

N. K. Al-nemrawi ◽

S. S. M. Alsharif ◽

R. H. Dave

Keyword(s):

Freeze Drying ◽

Sodium Tripolyphosphate ◽

Chitosan Nanoparticles ◽

Great Influence ◽

Ionic Gelation ◽

Drying Method ◽

Experimental Conditions ◽

Large Increment ◽

The Stability ◽

Formulation Variables

Objective: The aim of this work was to prepare chitosan nanoparticles (CS NPs) using sodium tripolyphosphate (TPP) as crosslinker and to study the effect of chitosan polymeric properties and experimental conditions on the properties and stability of NPs.Methods: CS NPs were prepared by ionic gelation method, using TPP as a crosslinker. The particle size (PS), polydispersity index (PDI), zeta potential (ZP) and the morphologies of the NPs were studied. CS NPs prepared by varying the concentration of TPP, Chitosan molecular weight and its degree of deacetylation, the stirring speed, the rate of TPP addition and the freeze-drying method to study the effect of these variables on the NPs. The stability of the CS NPs was evaluated by storing aqueous suspensions of NPs and comparing the PS, PDI and ZP at the beginning and the end of the experiment.Results: This study shows that the PS, ZP and dispersity of the NPs depend on the chitosan polymeric properties and experimental conditions. The NPs sizes range between 145.73 and 724.23 nm. They all carried positive charges ranging between+4.32 and+43.67 mV. Most of the NPs have the same sizes after freeze-drying, but showed higher monodispersity and ZP, indicating higher stability. After twenty days of studying the stability, the NPs that had low ZP showed a large increment in size in comparison to the highly charged NPs.Conclusion: In conclusion, the polymeric properties and formulation variables in the ionic gelation method have a great influence on the CS NPs formed.

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