Application Note No. 746/2021 - Immobilization of a natural extract by spray drying - Buchi
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Application Note No. 746/2021 Immobilization of a natural extract by spray drying Mini Spray Dryer B-290: Immobilization of a natural extract of truffle oak by spray drying for cosmetics use. Hortense Plainfossé1,2, Maïlys Delcroix 2, Manon Trinel1, Pauline Burger 2, Xavier Fernandez1, Aurélie Demont3 1 Université Côte d’Azur, CNRS, ICN, Nice (France) ; 2NissActive, Pépinière InnovaGrasse, Grasse (France), 3BUCHI Labortechnik, Flawil (Switzerland) www.buchi.com Quality in your hands
1. Introduction The global cosmetic market is in constant evolution for the past years. Customers are more and more concerned with the type of product they use and the market needs to adjust to meet these new requirements [1]. Customers are moving from products of synthetic origin, synonym of danger for the health and the environments, to products with a natural origin [2]. To face these changes, the cosmetic industry is adapting by offering natural alternatives to conventional products, valorizing natural raw materials and using more environmentally friendly processes [3]. Thanks to major technological advances developed by BUCHI, it is now possible to develop natural cosmetic ingredients that meet consumer expectations. The contact of a vegetal raw material with a solvent (organic or aqueous) enables to solubilize different kinds of metabolites of interest (polyphenols, tannins, flavonoids, terpenoids, amino acids, peptides,…) with different interesting biological activities (anti-ageing, whitening, soothing activities,…). The extraction of these compounds of interest is mainly based on their affinity with the extraction solvent used. The final extract is then obtained through filtration and removal of the plant residues. When the extraction solvent used is volatile, it is possible to concentrate the extract by evaporation of the solvent. The extract obtained, generally called "dry extract", is then in the form of a more or less viscous paste, depending on its composition [4]. This paste-like consistency makes the extract difficult to formulate (difficulties in sampling, solubility,…) and requires to modify its shape in order to facilitate its incorporation into a finished cosmetic product. For this purpose, two types of support (liquid and solid) can be used, depending on the desired final form of the ingredient and the galenic of the finished product. Extracts in liquid form can be obtained by two methods. When the solvent used for the extraction step is compatible with cosmetic use, the extract in liquid form is obtained by simply filtering the plant residue. When the solvent is not compatible with a cosmetic use, it is evaporated and the dry extract is diluted in another suitable solvent such as propylene glycol, glycerin, water or various vegetal oils. Putting an extract on a solid support is more complex and often requires specific equipment to dry the extract on the carrier. Different types of carriers (polysaccharides, silica, starch, gelatin, methylcellulose,…) and several drying techniques based on different processes can be used. The process can be chemical, (polymerization in emulsion), physico-chemical (evaporation) or physico-mechanical (spray-drying or freeze-drying) [5]. Solvent evaporation is the most widely used technique to prepare solid extracts at laboratory scale because of its ease of use and the possibility to work with either hydrophilic or lipophilic support [5]. The dry extract is first diluted in an appropriate solvent, the solid carrier is then added with a weight ratio extract/carrier between 1:1 and 1:10. The powder is obtained after concentration of the solution by evaporation of the solvent. The obtained powder is however lacking homogeneity. This can lead to differences in active concentration in the final product and therefore becomes a problem when the ingredient is incorporated in a final cosmetic product. This technique also has the drawback not to be easily transposable at industrial scale. Freeze-drying and atomization are two interesting techniques for drying natural extracts and obtaining products with high added value [6]. Freeze-drying is commonly used to dry heat Application Note 746/2021 April 2021 2/7
sensitive components in the nutraceutical field and may not require the help of a carrier [7]. The
final extract has a lamella shape with pores resulting from the sublimation process resulting in a
non homogeneous mixture [8]. Spray drying on the other hand enables to achieve homogeneous
powders with remarkable properties and interesting yields, when working with optimized
parameters. The process can easily be transposed to the industrial scale, moreover the
production cost of this technology is low, encouraging therefore the selection of spray drying to
obtain a cosmetic ingredient adapted to the formulator constraints [5].
2. Spray drying principle
Spray-drying is a physico-mechanical process in which a liquid is dispersed into fine droplets
before being dried with a stream of hot gas. Several atomization devices are available
depending on individual requirements. The more common atomizers are pressure nozzle, two-
fluid nozzles, ultrasonic nozzle and rotary disks (Figure 1) [5]. The choice of nozzle mainly
depends on the scale of the process, the properties of the feed and the final product
requirements [10-13]. The Mini Spray dryer B-290 is equipped with a two fluid nozzle that uses
pressurized gas (often compressed air or nitrogen) to disperse the liquid into fine droplets which
are then dried. Combined with an Inert Loop-295, an organic solvent trap, and the B-296
dehumidifier (Figure 2), samples based on organic solvents and aqueous mixtures can be
processed using the Mini Spray Dryer B-290.
Figure 1 : Spray drying process (BUCHI)
Application Note 746/2021 April 2021 3/7
The sample to be sprayed consists of the extract and the support material, dissolved in a solvent. Water is the most commonly used solvent, but it is possible to use an organic solvent to help dissolve the extract. A wide range of support materials can be used: polysaccharides (maltodextrin, starch, sucrose, gum arabic, etc.), proteins (gelatin, casein, etc.) or even synthetic polymers (acrylic polymer, etc.) are often employed in the field of cosmetics [5]. Inorganic materials such as silicate or clays can also be used. The choice of the material depends mainly on the type of finished product in which the ingredient will be incorporated and on its function. Maltodextrin, a polysaccharide, is commonly used for atomizing natural extracts, due to its high solubility in water, its low viscosity [5] and its ability to form stable emulsions [8]. It positively influences the stability of the ingredient and reduces the risk of agglomeration that may appear during storage [6]. However, care should be taken to use the minimum amount of carrier material necessary to avoid reducing the biological activities of the active ingredient [5]. The dry extract / solid support mass ratio is between 1/1 and 1/10, depending on the composition of the extract, the nature of the support and the quality of the desired powder. The quality of the final product and the atomization yield depend on both the nature of the support material and the atomization conditions. These influence the morphology of the powder (particle size) and its moisture content, two parameters that can influence the solubility of the ingredient in the finished product. The temperature of the air entering the spray cylinder, the air flow, the aspirator settings, the humidity of the drying gas, the total concentration of solid in the liquid to be sprayed (extract + support material) , the extract / support material mass ratio or the solvent used to dissolve the extract are parameters to optimize in order to obtain a powder of the desired quality [6]. Laboratory scale spray dryers enable the determination of optimal parameters at the laboratory scale according to the composition of the natural exctract (Figure2) and by processing small sample volumes. These parameters are then easily transferable to higher volumes, allowing an efficient production of natural cosmetic ingredients in solid form, meeting the expectations of formulators. Figure 2: BUCHI Mini Spray Dryer B-290 (left), Inert Loop B-295 (top right) and dehumidifier B-296 (bottom right) Application Note 746/2021 April 2021 4/7
3. Experimental procedure
This study focused on spray drying an extract of the aerial parts of truffle oak. This extract
expected to present interesting ant-aging properties was obtained by hydro-alcoholic steeping
(water/ethanol, 80/20, m/m) and was presented in the form of a sticky and viscous paste,
unsuitable for use in cosmetics (Figure 3) [9].
Figure 3: Dry extract as a paste before spray drying (left) and as a solid formulation using maltodextrin and a spray
drying process (right).
Using BUCHI Mini spray dryer B-290, the operating conditions were optimized to obtain a powder
that is easy to handle by the operator, with a satisfactory yield for industrial application.
The dry extract was first diluted in an 80/20 hydro-alcoholic mixture used to carry out the steeping.
Maltodextrin (dextrose equivalent 13.0 - 17.0%) was selected as the carrier material due to its
water solubility. A weight ratio of extract to maltodextrin 1/2 was set since the extract was highly
viscous (Table 1). The total solid concentration in the solution to be sprayed was set at 0.15 g/mL.
Table 1: Experimental conditions
Carrier Ratio carrier/extract Solvent Solid concentrations
H2O/EtOH
Maltodextrine 2/1 m/m 0,15 g/mL
(80/20 v/v)
The parameters used are presented in Table 2. Three different inlet temperatures (160°C, 180°C
and 200°C) were used to evaluate its influence on the quality of the spray dried product (yield and
percentage of moisture in the powder). These tests were carried out from 20 g of extract, the
minimum usable quantity to have a significant atomization yield (Table 3).
Table 2: Spray drying setting for the oak extract
Parameters
Inlet temperatures 160 °C, 180 °C, 200 °C
Outlet temperatures 90 - 110°C
Feeding speed 20 %
Spray gas Nitrogen
Spray gas flow 473 L/h
Aspirator 100 %
Table 3: Tested conditions for spray drying of the extract QP_ha_80/20
Weight Inlet
Weight extract Volume water Volume ethanol
maltodextrine temperature
18,1 g 36,1 g 284 mL 72 mL 160 °C
20,0 g 40,0 g 320 mL 80 mL 180 °C
20,0 g 40,0 g 320 mL 80 mL 200 °C
Application Note 746/2021 April 2021 5/7
4. Results and discussion
Regardless of the inlet temperature, a yield greater than or equal to 70% was obtained, which is
considered satisfactory on a laboratory scale (Table 4). Experience has shown that this yield
would be in the order of 95% by transferring these parameters to the industrial scale, using a
larger drying chamber. The best yield is obtained with an inlet temperature of 160°C.
The appearance of the three powders obtained is satisfactory for integration into cosmetic
formulations. Their moisture content, estimated at less than 3%, is also suitable.
Table 4: Influence of the inlet temperature on yields
Inlet temperature 160 °C 180 °C 200 °C
Yield 79,4 % 75,5 % 69,8 %
The Mini Spray Dryer B-290 has a drying efficiency of around 1 L/h, allowing a large quantity of
extract to be processed in a short period of time for laboratory work. Moroeover, it is rather easy
to use and gives the user the possibility to follow the atomization process through the glass
module.
The parameters determined on the laboratory scale spray dryer (inlet temperature 160°C) are
those that will be transposed for the industrial production of the anti-aging oak ingredient.
5. Conclusion
The BUCHI Mini Spray Dryer B-290 allows to obtain ingredients in solid form with an excellent
yield and interesting properties that can easily be integrated in a cosmetic formulation. An
example of a natural formulation of a face lotion integrating spray dried extracts is presented in
Table 5. Thanks to this atomization process, it is possible to solve the problems encountered
when using natural extracts and thus meet the expectations of developers. Its drying efficiency
and ease of use make it an indispensable piece of equipment for the development of a natural
cosmetic ingredient.
Table 5: Exemple of a natural face lotion using the spray dried extract
INCI Amount (%)
Aqua qsp 100
Glycerin 2.00
Caesalpinia Spinosa Gum 0.20
Polyglyceryl-4 Laurate/Sebacate (and) Polyglyceryl-
1.00
6 Caprylate/Caprate (and) Aqua
Polyglyceryl-4 Laurate/Succinate (and) Aqua 1.00
Aqua (and) Sodium Benzoate (and) Potassium
0.50
Sorbate
Spray dried extract 0.50
Parfum 0.50
Citric Acid 0.30
Application Note 746/2021 April 2021 6/7
6. Acknowledgements
We greatly acknowledge Hortense Plainfossé, Maïlys Delcroix, Manon Trinel, Pauline Burger and
Xavier Fernandez from the University Côte d’Azur, Nice (France), and from NissActive in Grasse
(France) for sharing their expertise in research of active compounds in plant material for cosmetic
research, for sharing the data and the support for the development of this Application Note.
7. References
[1] Speed dating Cosmétique : rencontre avec les experts Business France Available online:
https://export.businessfrance.fr/programme-
france/001EVT003213+nouveaute.html?xtor=EPR-94 (accessed on Oct 4, 2018).
[2] Herich, D. The natural organic beauty consumer: 2008-2018. Global Cosmetic Industry,
2018.
[3] Dufreuil, A. Cosmétique - vers une formulation plus verte. Agrobiobase, la vitrine des
produits biosourcés, 2011.
[4] Fernandez, X., Michel, T., Kerdudo, A. Conservateurs pour cosmétiques - Antioxydants et
anti-UV. Techniques de l’ingénieur, 2012, J2285 v1.
[5] Casanova, F., Santos, L. Encapsulation of cosmetic active ingredients for topical
application – a review. Journal of Microencapsulation, 2016, 33, 1–17.
[6] Caliskan, G., Nur Dirim, S. The effects of the different drying conditions and the amounts
of maltodextrin addition during spray drying of sumac extract. Food and Bioproducts
Processing, 2013, 91, 539–548.
[7] Fang, Z., Bhandari, B. Encapsulation of polyphenols – a review. Trends in food science &
technology, 2010, 21, 510–523.
[8] Ezhilarasi, P.N., Indrani, D., Jena, B.S., Anandharamakrishnan, C. Microencapsulation of
Garcinia fruit extract by spray drying and its effect on bread quality: effect of spray dried
microencapsulates on bread quality characteristics. Journal of the Science of Food and
Agriculture, 2014, 94, 1116–1123.
[9] Plainfossé, H., Burger, P., Azoulay, S., Landreau, A., Verger-Dubois, G., Fernandez, X.
Development of a natural anti-age ingredient based on Quercus pubescens Willd. leaves
axtract— A case study. Cosmetics, 2018, 5, 15.
[10] Poozesh, S.; Bilgili, E. Scale-up of Pharmaceutical Spray Drying Using Scale-up Rules: A
Review. Int. J. Pharm. 2019, 562, 271–292.
[11] Introduction to Spray Drying. In Spray Drying Techniques for Food Ingredient
Encapsulation; John Wiley & Sons, Ltd, 2015; pp 1–36.
[12] Drusch, S.; Diekmann, S. Microencapsulation by Spray Drying. In Handbook of
Encapsulation and Controlled Release; CRC Press, 2015; pp 35–46.
https://doi.org/10.1201/b19038-6.
[13] Li Xin, H.; Mujumdar, A. Spray Drying and Its Application in Food Processing. In Handbook
of Encapsulation and Controlled Release; CRC Press, 2015; pp 47–69.
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