The final moisture content and water activities of blueberry FMFD and SD powders are shown in Figure 3B and 3C, respectively. All FMFD samples had no significant (p > 0.05) differences in moisture content compared to SD samples of similar composition. However, there were two powders which had the notably highest and lowest moisture content, namely FMFD with MD/WPI = 0.4 and SD360 with MD/WPI = 1.6, respectively. Numerous studies have compared the moisture contents of freeze-dried and spray-dried powders. Generally, they suggest that spray-drying gives a lower moisture content than freeze-drying due to the higher temperature in the spray-drying process. 32,36
Mefenamic acid, an anti-inflammatory drug, exhibits poor water solubility, dissolution and flow properties. Thus, the aim of the present study was to improve the solubility and dissolution rate of Mefenamic acid by preparing microparticle by Freezedrying technique. Mefenamic acid microparticle containing different ratio of β-cyclodextrin were produced by Freezedrying using water and Isopropyl alcohol as solvent system to enhance solubility and dissolution rate. The prepared formulations containing different ratio of drug and polymer were evaluated for in vitro dissolution and solubility. The prepared formulations were characterized by scanning electron microscopy, differential scanning calorimeter, X-ray diffraction and Fourier transform infrared spectroscopy. Dissolution profile of the Freeze dried microparticle was compared with its physical mixture and pure sample. Freeze dried microparticle exhibited decreased crystallinity and the solubility and dissolution of the microparticle containing different ratio of drug and β- cyclodextrin were significant improved compared with its physical mixture and pure sample of Mefenamic acid. Dissolution of microparticle containing 1:3 w/w (FD 3) showed higher % release i.e. 98.6 % in 60 min compare to other formulation. Consequently, hence, from the above result it can be conclude that Freeze dried microparticle of Mefenamic acid is a useful technique to improve the solubility and dissolution of poorly water soluble drug like Mefenamic acid.
that sense, freeze-drying processes with water exclusion would often cause the physical instability of proteins with partial unfolding and the formation of protein aggregates. Furthermore, even after successful lyophilization, solid protein formulation may experience a variety of instabilities including aggregation, oxidation, the Maillard reaction, and hydrolysis; thus, its long-term storage stability may still be limited, particularly at high storage temperatures. These instability issues during freeze-drying as well as storage may be minimized by proper selection of pH, residual moisture content, and more importantly, formulation stabilizers such as cryoprotectant and lyoprotectant. 3 Various examples of
Freeze-drying is a process, in which a product is R rst frozen and then dried by sublimation of the ice. The total process involves four steps: freezing; sublima- tion of the ice, called main drying (MD); desorption of the water bound to the solid, called secondary drying (SD); and packing in containers to exclude absorption of water and / or oxygen from the atmos- phere. By freeze-drying a product unstable in water is transformed into a dry, stable product. The process has to be developed to satisfy four demands on the R nished product: its volume remains that of the frozen substance; the structure and the biological activity of the dried solid correspond as far as possible to those of the original substance; the dried product remains stable during storage, if possible at temperatures up to # 40 3 C and for up to 2 years; and with the addition of water the original product is quickly reconstituted. This article summarizes the problems and solutions to achieve these aims.
Medication Costs: Containing 0.5g of metronidazole, each bag of form B costs 7.07Yuan, which could be infused directly without reconstitution making the total medication costs with form B for one intravenous dose is 7.07Yuan. Each vial of form A, containing 0.915g of freeze-drying powder equal to 0.5g of metronidazole, costs 14.78Yuan, which should be reconstituted in 100mL of 0.9% NaCl or 5% glucose injection before infusion according to the drug instruction approved by the State Food and Drug Administration (China).
For bone tissue engineering application, a porous scaffold with interconnected network is highly sorted for cell guidance, cell attachment and growth in the three dimensional structure. Using freezedrying technique, we produced three types of scaffolds. PCL scaffold, PCL/HA nanocomposite scaffold and a conductive scaffold PCL/HA/PPY. Conductive scaffold was produced to render the scaffold conductive. The scaffolds were characterized and evaluated using a number of techniques. Composite scaffolds with suitable pore size distribution were obtained by freezing the polymer solution mixture at -18C, which was controlled by the polymer and solvent phase crystallization. From the result, the wettability and porosity of the sample were observed to increase more with the incorporation of Polypyrrolein the scaffold than in Polycaprolactone scaffold alone. PCL/HA/PPY scaffold had a lower porosity than PCL and PCL/HA scaffolds. The compressive modulus increased form 1.15Mpa (PCL) up to 6.10Mpa in PCL/HA/PPY scaffold. Incorporation of PPY polymer rendered the scaffold conductive. Hence, the characteristics of PCL/HA/PPY scaffold studied in this present work shows good prospect and may probably be employed for bone tissue engineering applications.
A perfect scaffold material must fulfill a few conditions and possesses some qualities. The scaffold must be capable of being fabricated in precise shapes. It must possess a measured porous architecture to permit cell penetration. Also, the scaffold material must aid cell attachment, development, tissue restoration, and vascularization. It must have good mechanical properties, particularly at large deformations, to protect structural reliability during culture and utilization [2-4]. Furthermore, the scaffolds must be osteoconductive. Chitosan, being one of the extensively studied polymers and promising for use as scaffold material in bone tissue engineering application, is the copolymer of D- glucosamine and N-acetyl-Dglucosamine . It is biodegradable, biocompatible, non-toxic and also possesses antibacterial properties. In this study, chitosan because of its several advantages was used in coating already fabricated conductive PCL/HA/PPY composite scaffold which was fabricated using freezedrying technique.
Process analytical technology (PAT)-tools were used to monitor freeze-drying of Bacille Calmette-Guérin (BCG) at pilot and production scale. Among the evaluated PAT-tools, there is the novel use of the vacuum valve open/close frequency for determining the end- point of primary drying at production scale. The duration of primary drying, the BCG survival rate, and the residual moisture content (RMC) were evaluated using two different freeze- drying protocols and were found to be independent of the freeze-dryer scale evidencing functional equivalence. The absence of an effect of the freeze-dryer scale on the process underlines the feasibility of the pilot scale freeze-dryer for further BCG freeze-drying pro- cess optimization which may be carried out using a medium without BCG.
The effect of Oven and freezedrying methods on the proximate composition, anti-nutrient and selected physical attributes of soursop flours were determined using standard methods. The fruit pulp was frozen at -30 and freeze dried at -40 for 72hrs while oven drying was performed at 70 for 48hrs. Oven drying significantly (p<0.05) lowered the fat (7.30±0.23%), moisture (12.40±0.29%) and carbohydrate (40.70±0.12%) content of soursop flour while freezedrying significantly (p<0.05) lowered the protein (18.72±0.10%), fibre (12.30±0.23%), ash (6.30±0.17%) and energy (212.704±0.10%) content of the flour. The oven dried flour had higher phytate (0.03±0.10%) and oxalate (0.03±0.00%) content while the freeze dried flour had higher tannin (0.52±0.00%) content. The physical attributes of the flours however revealed that the freeze dried flour significantly (p<0.05) had higher values for viscosity (32.50±0.29%), water absorption capacity (57.30±0.17%), swelling index (50.10±0.06%), solubility (22.30±0.17%), oil absorption capacity (24.60±0.23%) and emulsion capacity (24.60±0.23%) while the oven dried flour had higher values for bulk density (421.20±0.12%) and foam capacity (25.30±0.17%). Freeze dried soursop flour had better physical attributes, lower nutrient and anti- nutrient content.
Image analysis has been used as a potential tool for the characterization of the texture of ultramacroporous foams prepared by freeze-drying. It has been shown that this technique actually provides valuable information on the structure of this kind of material. Image analysis of SEM micrographs of transverse sections at two different magnifications gave information on both the macroporosity (10 µm < width < 100 µm) and ultramacroporosity (width > 100 µm). Moreover, the foam anisotropy has been determined by image analysis of longitudinal sections.
A few studies have been conducted regarding the freeze- drying of kale. Korus (2011) showed that freeze-dried kale leaves contained higher levels of antioxidants than did air- dried material: polyphenols, vitamin C, and antioxidant activity expressed as trolox equivalent were, respectively, 36, 15, and 33% higher. Moreover, Korus (2012, 2013) also pointed out that the levels of chlorophylls, carotenoids and individual amino acids content were higher in freeze- dried than in air-dried products, and from a practical point of view, she concluded that blanching was not a necessary procedure before drying kale leaves. Still, there is virtu- ally no data in the literature on the freeze-drying kinetics
Freezedrying process time depends on the amount of water to be removed and the size of bone. In routine bone processing practices, large size bone is freeze dried separately from small size bone because the large bone requires longer time to dry. However there is no clear requirement to dry separately small size bones of different structures. Small bones of the same size are normally pooled for freezedrying to save time and electrical cost. The present study was aimed to identify influence of bone structure on the freezedrying process of the small size human cortical and cancellous bone cubes to the desired percentage of water content of less than 6%. The findings would validate the standard operating procedure for freezedrying cycle for bone allograft cubes for preservation purpose.
In addition to fresh consumption, tomatoes are processed into various products, including juices, ketchup, sauce, paste, puree and powder. The solid waste (70-75 % of fresh tomatoes), remaining after juice/pulp extraction and processing, consists of skin, seeds and fibrous matter. This waste along with damaged tomatoes are dumped as a solid waste or to some extent used as fertilizers . Lycopene contents in the skin, seeds and fibrous matter of tomato waste vary significantly. It is suggested that 72-92 % of lycopene was associated with the water insoluble fraction and the skin . Based on these observations and considering the nutritional value of lycopene and the continuous increase in the production of tomatoes and tomato products, there has been significant interest in recent years to retrieve and utilize tomato waste-by-products. This study investigated the presence and recovery of antioxidant (lycopene) from laboratory and industry generated tomato waste by-products using ultrasonication and freezedrying techniques. Additionally, the antioxidant activities of freeze dried industrial tomato waste by-products were assessed using 2 different in vitro methods, namely: 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and [2’.2’-azinobis(3-ethylbenzothiazline-6- sulfonic acid diammonium salt] (ABTS) free radical scavenging assays.
Calculation shows that the freezedrying method could maintain the viability of probiotic bacteria L. acidophilus up to 93.47%. This means the use of coating material of skim milk 10% and 20% maltodextrin could keep bacterial cell viability. The use of a combination coating of protein and carbohydrate-based can produce optimum efficiency as a microcapsule wall .Selection of the coating material is very influential in maintaining the viability of bacteria during the microencapsulation process. According to , as a coating material skim milk roles in preventing cell damage by stabilizing the membrane and provide a protective layer on the cells because the lactose presence in skim milk reduces bacterial cell damage during the freezedrying process. This is due to lactose has a low molecular weight so as lactose can enter into bacterial cells and provides protection from two sides of the cell membrane during the freezedrying process . Maltodextrin is included in prebiotic because it is classified as complex carbohydrates. Maltodextrin is often used because of its properties such higher solubility, capable of forming a film, has low
synthesizedis shown in Figure1 (a, b). Freezedrying method has been already shown to get fine and homogeneous particle distributions. Several rewards support the choice of this procedure, namely, the homogeneous reactant distribution, the presence of a carbon source, and mild annealing temperatures. Freezedrying results in the high purity products.
The washed strips were then kept in saturation water and subjected to freeze-drying using high vacuum equipment (Lanbconco Free Zone, USA). Their morphologies are shown in Fig. 1. Compared to air-drying, freeze-drying is a more effective approach to fiber structure preservation, which is also beneficial to reduce microstructural changes caused by microfibril aggregation in cell walls during water loss.
The prepared PCL, PCL/HA and different percentage of PCL/HA/PPY were placed into separate glass vials. The glass vials containing the solutions were then moved into a freezer at a preset temperature of -18C for overnight to solidify the solution. The frozen solution was then transferred into a freeze-drying vessel (Labconco –Freezone, USA) and freeze- dried for 48 hours to remove the solvents.
The present microencapsulation is based on spray-drying techniques. One disadvantage of spray-drying technology is the elevated temperature which is necessary for drying. High temperatures lead to an increased oxidation of PUFA so that a drying process at low temperatures (freeze-drying) is expected to be an alternative for the microencapsulation of fish oil. Maltodextrin is a hydrolyzed starch commonly used as a wall material aid because of their relative benefits such as cheapness with no colour, neutral little taste, low viscosity and protection against oxidation used as wall material in microencapsulation of food components 6 . However, the main problem of this