- Shiva Shanker Kaki added an answer:6Any reasons for low Vitamin A (palmitate) recoveries from Infant Milk Formula?
We obtain inconsistant low Vit A palmitate recoveries from infant milk formula (spray dried). Results (normal phase HPLC) from different accredited laboratories give inconsistant results.
Vitamin A palmitate is added to an infant milk formula base prior to homogenization, pasteurization and spray drying.
Any assistance will be much appreciated. Thank you
May be you can try the AOAC method?Following
- Debashish Sarkar added an answer:4Is there any way to break starch into 30-50nm polymer chain?
I am trying to spray dry a carbon precursor with silica np to produce mesoporous carbon. Could corn starch be broken into small polymer chains of size around 30nm...
Thank you for taking out your time to answer my question.
@Mike, I tried using amylase. I gelatinized starch slurry and then added alpha amylase. PH 5,37C,150rpm. I took out few drops from the slurry after every 15 minutes for one hour. Then I did DLS study of these samples. Sample taken at 0minute shows a peak around 4um. 15mins around 300nm. But after that, as time increased , the size kept on increasing. Probably, the fragments started to agglomerate? Not sure. I thought of ultrasonic treatment after this. But I found a paper that tried to do that but instead of decreasing the size it actually increased it!
@Alexander, I will try acid hydrolysis and ultrasonic. Will update the result.
@Jihan, could you suggest a precarbon source that is cheap and easily available and suitable for spray drying. (have tried glucose, sucrose - did not work)
I will try solvent displacement method this week. But I am not sure how to add ethanol and how will it effect the size.Following
- Ahmad Ziaee added an answer:5Unstable spray in spray drying - can anyone help?Can someone please share some thoughts on why do I get an unstable spray in spray drying? The spray is pulsating (looks like it is spitting). It does not matter what kind of solvent/solution/suspension/emulsion I am feeding, the result is always the same. The system is Büchi P-290.
I know it is too late but just to help others searching for the same problem.
This seems to me that either something is wrong with the nozzle or the feed rate or atomizing pressure is too low. Trying to play around with these two factors. There may be also the chance of clogging in the nozzle. If you have an spare nozzle check it with the same operating conditions and compare the outcome.
At the end if none of these worked for you, check with Buchi there may be something more serious than operational conditions.Following
- Ali Al-khattawi added an answer:3Having trouble with Nano Spray Dry (solids stay in the particle collector wall). Does anyone know a good cationic adjuvant for this purpose?
I am using a anionic drug (490mg) plus an adjuvant (250mg of Polaxamer 188) in 100mL of ultrapure water (Solution A)
Then using a mother solution of an anionic polyssacharide (10mg) in 100mL (solution B)
I pick 25mL of A and 25mL of B (50mL final) and spray dry
But, when I spray dry (Buchi Nano Spray Dryer B-90), I cannot recover anything because all of these solids stay in the particle collector wall.
I am wondering that:
1) the solution (A+B) is too moist, because i am using 60 celsius.
2) the solution have high concentration of drug/adjuvant.
3) Polaxamer 188 is non-anionic and I using two anionic compounds). But all cationic adjuvants that i searched (I.e. benzalkonium hydrochloride) show high pulmonary toxicity.
I have two options that i can try:
1) Change the temperature (60 to 100 celsius to observe that the moist is the problem)
2) Change concentrations of Polaxamer 188.
Anyone can help?
Did you use exactly 100C? because that is still low.
I assume by collector wall you are referring to the cyclone?
Did you check the total concentration of solids you have in liquid. That's another reason why the particles may not reach the product collection tube if the particles do not have enough solids and are low in density. If you have a picture of the spray dryer and the deposit and you can send it to me, I can probably help you further. my email is email@example.comFollowing
- V.P. Komaristaya asked a question:OpenMethod of Blakeslea trispora biomass treatment to preserve beta-carotene?
Dear Colleagues, could you please advise how to treat wet Blakeslea trispora biomass harvested from the fermenter before spray drying to prevent beta-carotene losses during drying and storing: what is the best composition of antioxidants to add and when is the right time to add them?Following
- Ahmad Ziaee added an answer:12The applicability of spray drying in the pharmaceutical industry: Would you consider utilizing spray drying as a crystallization process?
I am a young researcher and I recently started my PhD project, which will largely be centred around the practical aspects of continuous crystallisation by spray drying. I was hoping to benefit from your expertise and the diversity of each of your individual backgrounds related to this subject.
What do you think are the major aspects related to the applicability of spray drying in the pharmaceutical industry? Would you consider utilizing spray drying as a crystallization process? Based on your experience, can you recommend where computational modelling can be used to best effect to support a conceptual process design?
Thank you very much for your time! I would appreciate your feedback.
Kind regards, Frederik
You can take a look at: "A spray-drying strategy for synthesis of nanoscale metal–organic frameworks and their assembly into hollow superstructures". As all MOFs are crystalline materials I think this paper will help you find the critical conditions for crystallization by SD.Following
- Pushpani Sharma added an answer:4Anyone an expert on Antioxidant Assay (ABTS)?I'm a total newbie on antioxidant assay. Trying to determine antioxidant activity of an encapsulated polyphenolic compound
So I was looking at some journals for ABTS Assay procedures, and got quite confused as below:
This is the confusion part for me:
For (1), 7mM ABTS solution mixed with K2S2O8 solution. In that mixture, the concentration of K2S2O8 is 2.45mM.
Whereas for (2) equal amount of 7mM ABTS solution is mixed 2.45mM K2S2O8 solution. Doesnt that mean the final concentration of K2S2O8 in that mixture is 1.225mM.
Is (2) correct. Are they trying to get final concentration of 1.225mM. Or am I reading it incorrectly?
Can anybody please tell me how to make the reagents for ABTS antioxidant assay??? How much ml of ABTS stock solution should be mixed with how much ml of potassium persulphate?Following
- Harald Schuchmann added an answer:4On which parameters does the Bulk density and particle size of a spray dryed material depend?
Is there any relation between type of nozzle used and particle size, its distribution, bulk density (BD) of the spray dried material? How does feeding pressure and hot air temperature affect the BD of the material?
The effect of drying temperature on the bulk density of the spray dried powder is controversial.
This is due to the drying kinetics and solid content. Particles can dry by shrinking or as hollow spheres. This mainly depends on the initial solid content. A rapid formation of a skin fosters hollow spheres, as long as the steam pressure inside the sphere is not blowing holes into the already formed skin.
=>for equal droplet sizes a high solid content and drying at moderate air temperatures usually gives lower bulk densities.Following
- Harald Schuchmann added an answer:3How i can get good flowability for spray dried skim milk powders during the agglomeration process?
I am using lab-type spray dryer in order to obtain skim milk powder. My outlet temperature is 85-90 C. Moisture content of product is in the range of %3-4. After production i put my powders in desiccator to cooling without obtaining moisture and then i am using top agglomerator for instantizing process. During the agglomeration step i cannot obtain a good flowability from my powders. All powders starts to stick the conical chamber before spraying binder and agglomeration process stops. Inlet air rate 12-14 m3/h and air temperature 60 C . What do you recommend to obtain a good flowability and agglomeration?
Just to see, if I understand your problem. Your skimmed milk powder leaves your lab spray dryer as a fine powder. You cool it, keeping 3-4 % moisture content. Then you put your powder into your conical chamber and before you start to spray your binder liquid onto the powder it lumps in an uncontrolled way?
What is the time for your powder outside the desiccator before it starts clogging? What is the air humidity?
I would guess that your powder is very fine if you use a lab spray dryer. This may create a higher amount of amorphous lactose. If your humidity and air temperatur are high enough incorporated water will be free and your powder becomes sticky. If you use a normal moisture analyser should be able to see the higher water content, if you take a sample of your aggregated powder and compare it to the original water content.
Industrially this is avoided by recrystallizing the lactose (or other sugars) while moving them (e.g. fluidized bed) before final drying or agglomeration. But be aware that crystalline sugar has slower dissolving kinetics than amorphous sugar.
- Osman Taylan added an answer:2What is the cost of spray drying?
I am trying to derive a cost model for the spray drying process. I need the process flow, relative cost of equipment, process for zircon, magnesium oxide, alumina powder mixture to sprayy dry powder to make knee implants. Difficult to understand ho to effectively measure the costs. I am on a tight schedule to calculate this so your help would be appreciated.
I had some resources regarding the cost calculations, however, I could not find them to post you..can you search from internet?Following
- Prabhakara Rao Pamidighantam added an answer:3How can I form a stable emulsion of fish roe that can be spray dried?
I have tried solubilizing the fish roe in dilute salt solutions. But that still forms 2 separate layers. How do I form a stable emulsion?
Particle size reduction along with addition of gums (guma acacia or guma karaya or gum tragacanth) can stabilise the emulsion by suspending the fish roe. These particles may pose a problem during atomisation in a spray dryer, hence disk type atomisers are preferable,Following
- Don Gabycito added an answer:6Spray drying microbe
The microbes increased in number after spray drying! does anybody know what is wrong?
- Yunier Paneque added an answer:1Can anyone share what are the critical characteristics of a flat fan spray tip?
We have an application requiring a flat fan spray and need to create a spray tip for use with foam mixture of air and soapy water. I have the general shape to create a fan spray but don't know how to adjust it to alter the spray characteristics.
The main operating parameters that may vary is the air pressure and the diameter of the nozzle orifice. The article that appears in this URL http://fluidos.eia.edu.co/hidraulica/articuloses/accesorioshidraulicos/losdiferentestiposdeboquillas/losdiferentestiposdeboquillas.html
can have more details of the types of nozzles and the equations describing the phenomenonFollowing
- Amine Rezzoug added an answer:2Does anyone know if cold spraying of Wc-Co powder on Polymer matrix composites is possible?
My thesis is about carbon/epoxy composite and my objective is to improve the surface properties of this type of composite.
I would to know if cold spraying of Wc-Co powder on Polymer matrix composites is possible
Thank you dear Grigory Ermolaev for your attention to my question and for your advice.
It is possible to use a bond coating layer to avoid the erosion of substrate?
- Prem Baboo added an answer:3What is the advantages of Rotary Dryer over Spray dryer?
Calcination of feed happens while steam @ 400 Deg Celsius enter the dryer.
Please see the comparison attached image,
- Ronan MacLoughlin added an answer:6Does anyone know of an aerosol device able to spray small quantities of liquid nano-microlitres?We would like to apply small quantities of liquid as an aerosol to specific objects.
Another option may be vibrating mesh aerosol generators/nebuliser. They are often used in coating applications.
Depending on which device you choose....your can effectively aerosols volumes <5ul.
Surface tension and viscosity may be a limiting factor if very low surface tension or very high viscosity.Following
- Gede Wenten added an answer:15What are the economic, easy and novel techniques to harvest the microbial mass from media in industry?
Freeze-drying and centrifuging are expensive techniques, spray drying has its own challenges and I guess the ultrafiltration might be challenging as well. Is there any other option?
Yes, ultrafiltration can be a good option in cell harvesting from processing and economic point of view. We have experience with SCP (single cell protein) harvesting, for more information please refer to,
We have also succesfully installed continuous ultrafiltration based microalgae harvesting system for Nanochlorophyl sp. with water removal capacity of 2000 liter/hour. We apply high cross flow velocity operation, filtration flux is very stable during concentration process.Following
- Thomas Trezza added an answer:4How to spray drying chicken meat powder with long shelf life?
I have sample of chicken meat powder from Europe. It's produced by using spray dry. From physical appearance: very fine powder, just like a common spray dried powder, it's not so free flow and some forms clumps.
When I dilute it, the solution gives opaque color and contain insoluble particles ( I assumed that this must be the real / dried chicken meat)
Then, it's document listed the ingredients, which are mechanically separated chicken meat (99% min), antioxidant. That's all.
When I read the documents, I'm so curious how the company made this product, using spray dry, but it seems like without any filler at all.
Then, I have a project to make a chicken meat powder like this in lab scale spray dry. I used the chicken hydrolysate (TSS 6-7), did some size reduction by using colloid mill. The slurry wasn't centrifuged, because I want to keep the insoluble particles & also the fat. Last, I did the drying process.
The result was soooo bad (as I expected before). Most of the powder tended to stick on drying chamber and I hardly could get the powder (very low in yield)
My questions are:
1. Is it really possible to spray dry chicken meat extract without any filler? Just like the chicken meat powder I have, contains min 99% chicken meat? Any tips?
2. How do you usually calculate the meat content in your chicken meat powder?
For example: I'm spray drying chicken meat slurry which consist of 50% chicken meat hydrolysate (TSS 10) + 30% maltodextrin + the rest is water. The chicken meat hydrolysate is made by using enzymatic hydrolysis. Let's say, I'm using 50% raw chicken meat + 50% water + enzyme.
Is it correct if I calculate it based on the total solid of chicken meat per 100 grams of chicken meat powder ??
3. I also tried to spray dry chicken meat powder with additional filler like maltodextrin & modified starch. After weeks or a months, the taste wasn't as good as it was fresh from spray drying. It became a bit rancid. What should I do to fix it?
4. How do you produce your chicken powder? Is it has long shelf life?
Thank you for your help & suggestions. If you have good references, journals or any other thing related to it, please let me know. I really appreciate it.
Last, please pardon my bad English. Thanks
A number of suggestions and thoughts to your questions. I'm not an expert in spraying but have done quite a fair amount work in this area in foods and pharmaceutical powders.
(1) I would start with understanding your process conditions. In spray drying your control of inlet, outlet temperatures and air flow into the chamber are very important. You might need to have a much higher than expected outlet temperature to ensure that you have enough heat to rapid drive off the moisture.
(2) Anticaking agents: there should be some that might work - but you may have to add more than you'd like to or are able to add on your label. Below are a few non-sillicates that you might consider. They could be used as an ingredient in the liquid phase prior to spray drying.
magnesium or calcium stearate
rice bran extract
yes - these have no or low water solubility as Harald explained. All of them might add some potential "off flavors" to your powder.
(3) Calculating meat content - this is a mass balance exercise. You need to know the dry solids content of your original material. Assume every dry solid is considered part of the "meat" (even the enzyme hydrolyzed solids). Most raw muscle tissue is around 70 to 80% moisture. 75% is a good starting point.
(4) Rancidity - yes I agree with Harald - the antioxidants are used to delay the onset of autooxidation (rancidity). There are many options. Some work better in some products than others. Here's a few to consider:
(a) synthesized antioxidants
BHT/BHA (butylated hydroxy toluene/butylated hydroxy anisole)
TBHQ (tert-butyl hydroquinone)
EDTA (ethylene diamine tetraacetic acid) - a chelator that makes metal ions (especially Fe2+, Cu2+) that catalyzed autooxidation unavailable for reaction.
(b) common food extracted antioxidants
mixed tocopherols/tocotrienols (Vitamin E)
ascorbic acid (Vitamin C)
Rosmemary extracts and botanical blends (many available commercially). You may need to use higher levels to have the same effectiveness as the earlier ones mentioned.
many polyphenolics from foods have some antioxidant properties but may not give you the desired shelf-life. You'll need to talk to a supplier about what options work well with your food system.
Regulatory approvals are country specific - so be sure to talk to the supplier about your situation.
(5) Sticking to the walls - consider your pH of the slurry material. Muscle protein has strong moisture binding properties. If you are closer to the isoelectric point (pI) of the material, you might be able to drive off water more effectively. At this pH proteins have minimal solubility and water binding ability (not zero, but their minimum)
Best of luck!Following
- Fabiola Porta added an answer:8Does anyone know a cationic polymer like Eudragit RS-100 for Nanocapsules, but biodegradable?
I will start to work with nanocapsules and need to use a cationic polymer, like Eudragit-RS100. But, we will spray dry these nanocapsules to use in pulmonary route. As we know, Eudragit RS-100 is not a good candidate because it is not biodegradable and can be stored at the pulmonary branches. Anyone know a polymer like EUDRAGIT - RS100, but biodegradable? Thanks in advance.
Chitosan could be an optionFollowing
- Chibuike C Udenigwe added an answer:5Can spray dried peptide loaded chitosan-alginate microparticles be produced?
Alginate is a water-soluble linear polysaccharide composed of alternating blocks of 1– 4 linked α -L-guluronic and β-D-mannuronic acid residues ,whereas chitosan is a co polymer of D-glucosamine and N-acetyl glucosamine.
They have favourable properties of biocompatibility, biodegradability, pH sensitiveness and muco adhesiveness.
Indeed, predominantly hydrophilic peptides can selectively get adsorbed on the chitosan-alginate matrix during encapsulation. However, water solubility may not be the best indicator of hydrophilicity; amino acid profiling would be beneficial here. Also note that strong wall-to-core interaction while enhancing encapsulation may also make it difficult to release the bound peptides when needed.Following
- Titus Sobisch added an answer:8How do I solubilize samples in aqueous solutions?
I am not from pharmacology background. But I would like to determine my sample aqueous solubility after spray-drying.
I chance upon paper below
Paper:Solid Dispersions of α-Mangostin Improve Its Aqueous Solubility Through Self-Assembly of Nanomicelle
"An excess amount from the samples (30 mg)
was added to 1 mL of phosphate-buffered saline (PBS)
at pH 7.4. The mixtures were vortexed for 5 min
and sonicated for 1 min and then centrifuged at
20,000g for 5 min. The supernatant was collected, filtered
through a 0.45-:m syringe filter, and diluted in
methanol. The samples were then analyzed using a
Since, my sample wall cannot be dissolved by PBS. I used water in replaced.
And my sample before spray-drying does not dissolve in water at all. So I just use 10mg.
But after spray-drying, its more soluble. Should I use it at 10mg as well? Or Excess like its written?
Because I want to compare before and after spray-drying solubility. Seems right to use it at 10mg. To compare properly
As long as the spray drying does not change the chemical composition solubility should be the same before and after the process, however, kinetics might be changed considerably.Following
- Philippa Ojimelukwe added an answer:6Which is best to use, Tween 20 and Tween 80?I'm wondering if its possible to use Tween 20/80 as a carrier/solubilizer to dissolve a hydrophobic substance. So far, I tried heating either Tween to around 70C, and it manage to dissolve my hydrophobic substances. But when I remove it from the heat plate, it starts to turn into like white solid like ghee, which I guess happens because of the decrease in temperature to the cloud point?
I'm trying to understand the differences in both Tween. I read somewhere that tween 20 is better to emulsify small amounts of lighter oils; whereas Tween 80 to emulsify larger amounts of heavier oil.
Then I check the HLB value (wikipedia) in which:
12 to 15: detergent
12 to 16: O/W (oil in water) emulsifier
16 to 20: solubiliser or hydrotrope
Tween 20 (16.7) seems like a better choice as it can act as a solubiliser or O/W emulsifier compare to Tween 80. But then other sources said tween 80 is better to emulsify larger amount of heavier oil?Which sounds like its better to solubilised my hydrophobic substances.
Erm. Do correct me if I'm wrong.
This information might help. Tween 20 has more hydroxy groups than Tween80. However, Tween20 works better in some experimental environments while Tween80 works better in other environments. There are no hard and fast rules since many factors affect emulsion stabilizationFollowing
- Nadiir Bheekhun added an answer:18What is a typical range of %wt solid fraction needed to obtain a concentrated ceramic slurry?
Can anyone suggest me what would be a typical range of %wt solid fraction needed to obtain a concentrated ceramic slurry for spray-drying? I have come across some works wherein 50 %wt of solid fraction have been employed.
Any justifications will be greatly appreciated.
Thanks a lot.
Dear Dr. Carlos,
Many thanks for your suggestion. I'll look into the Brongniart’s formula and the answers you provided.
- Ruiying Li added an answer:4How can I prepare chitosan nanoparticle sample for SEM?
I have some chitosan nanoparticle suspension and I would like to observe the morphology through SEM. I tried to air dry 1% suspension on SEM stub with carbon tab, but cannot observe sphere particle. I have read some papers using dry powder to do SEM after spray dry. However, we do not have a spry dryer. Is there any other methods I can use to prepare SEM sample? Thanks.
It depends on what kind of nanoparticles you are preparing. SEM is only suitable for nanoparticles that are able to keep their structure in the dry condition. For some chitosan nanoparticles, there are no nanoparticles as soon as the water evaporates.Following
- M. Ibrahim added an answer:13How long should we ball-mill a slurry before spray-drying?
For an aqueous slurry of weight 500g (water+binder+ceramic), what is a reasonable duration for rolled ball-milling before spray-drying?
At what would be a recommended speed of rotation?
Thanks in advance.
I would like to confirm with you guys, as my doubt falls under this topic, whether I can keep my ball-milled slurries for some days, say 10 days, and then spray-dry them? The spray-drying facility is quite far and not possible to get a slurry prepared and spray-dry on the same day. I plan to prepare a batch, then carry out the spray-drying.
Of course, I would be able to mix the ball-milled slurries using a magnetic mixer prior to spray-drying.
Your suggestions will really help.
- Roberto Molteni added an answer:7Any suggestions on how to improve the powder yield of spray dried oil emulsions?
How can we reduce the loss of oil emulsion samples in a spray drying chamber?
I agree with the answers, especially with Agarwal. I suggest to grasp the optimization issues with a fractional factorial design because there are many parameters (type of encapsulation, temperatures, flow rate etc). Later, you can refine it with a more precise factorial design.Following
- Denis Poncelet added an answer:2What is deference between spray drying and spray chilling in microencapsulation of probiotic bacteria and which one is better?
Microencapsulation as one of the most important techniques has remarkable effect on probiotic survival. There are several techniques to encapsulation of probiotic bacteria such as spray drying and spray chilling.
Spray drying you start from a wet suspension of cells. They are dried in a few second and bring to 40 to 60 °c. The stress is then quite high.
Spray cooling you start from a dry suspension of cells in melt material at 60-80 °c. Also stressful.
The way you master each process will control the final viability of cells. It may depend of the process parameters, the type of cells (very important) but also how you prepare and formulate the cells.
Now in application, spray drying beads would dissolve in water and not spray cooling beadsFollowing
- Mihai Ognean added an answer:5How can we improve the viability of lactobacillus casei after spray drying?
What are the factors that needed to be considered for a better survivability?
why the reproducibility in the viability count results in the MRS agar plating technique are lesser ? How can we improve this?
Also, in freeze dried sourdough production the LAB survival rate is increased if the culture is cold-adapted for 2h at a temperature with 15 oC lower then the cultivation temperature before freezing.Following
- Arun Chattopadhyay added an answer:3Can you suggest some training center for handling fluidized bed spray drying?
We have a culture collection with probiotic bacteria and produce in liquid form. We have now acquired the equipment and we want the probiotic powder. Thanks for your help.
You are most welcome.Following
- Md Ramim Tanver Rahman added an answer:4Does anyone have the experiences of Vacuum Spray Drying (VSD) of Concentrated Fruit Juice ?
VSD with low temperature treatment 40-60C.Following