Microencapsulation of citronella oil with carboxymethylated tamarind gum

Tamarind gum (TG) and carboxymethylated tamarind gum (CTG) were used as wall material to prepare citronella oil microcapsules by spray-drying. The aim of this work was to study the effect of wall-to-core ratio and fluid viscosity on emulsion droplet and microcapsule size, in order to maximize encapsulation efficiency (EE). EE was directly influenced by gum-to-oil ratio variations. Results showed that emulsion droplet size (D32) of CTG ranged between 0.18 to1.31 mm, smaller than those obtained for TG, which ranged from 0.87 to 2.91 mm. CTG microcapsules had a smooth surface and a spherical shape, as observed by scanning electron microscopy (SEM). Surface oil content and total oil content affected encapsulation efficiency. TG microcapsules showed lower EE than CTG microcapsules, which was related to the viscosity of gum to oil ratio. The maximum EE occurred at 1.14 gum to oil ratio for CTG microcapsules (87 %).The work presented in this paper was financially supported by the Faculty of Engineering, Burapha University, under Grant No. 12/2556. The author, K. Khounvilay, acknowledges the Fellowship of the One More Step: Erasmus Mundus Action 2 project, provided by the European Commission.info:eu-repo/semantics/publishedVersio

Kinetic models applied to soluble vitamins delivery systems prepared by spray drying

The incorporation of bioactive nutrient compounds such as vitamins into food systems can providea simple way to develop new functional foods. In this work, the controlled release of two vitamins(vitamins B12 and C), microencapsulated by a spray-drying process, is studied. With a properlydesigned controlled-release system, the compounds are released at the desired site and time, andat a desired rate. The main kinetic release models are applied and discussed. Also, the mainmechanisms associated to the release were identified. The use of models to predict in vivobio-performance is an advantage in the development of new products

Design and characterization of controlled-release vitamin A microparticles prepared by a spray-drying process

Vitamin A has been incorporated for the development of new products with applicability in food, pharmaceutical and cosmetic fields. Some research lines are focused in the preparation of food fortification and in the creation of enteral formulas. Moreover, the literature highlights the effect of vitamin A and other retinoids on anti-aging treatments. In fact, vitamin A plays a number of key roles in the human body, this micronutrient is involved in vision, reproduction, cellular growth and differentiation, embryonic development, epithelial cellular integrity and immunological activity. However, the poor solubility in aqueous systems, low polarity and very high sensitivity of vitamin A are the main concerns that need to be overcome during processing and storage. Microencapsulation technology may provide the required protection and stabilization of vitamin A, preventing or reducing its degradation. In the present work, microencapsulation of vitamin A (retinol) was studied using the spray-drying technology. Five concentrations of encapsulating agent were assessed (2, 5, 10, 15 and 20% (w/V) of arabic gum) and for each one a fixed amount of vitamin A (2% (w/V)) dissolved in coconut oil was used. The effect of coconut oil in the microparticles was also evaluated with the production of coconut oil microparticles (without vitamin A) and empty microparticles (without coconut oil and without vitamin A). The product yield obtained for the microparticles with coconut oil (with and without vitamin A) ranged from 13.6 to 28.6%, while for the microparticles only composed of arabic gum it was around 67%. For the different formulations of reagents investigated the microparticle size was between 3.473 and 10.400 m. Regarding the surface structure, all microparticles showed spherical form and rough surfaces. Vitamin A release studies were performed and validated by a UV/VIS spectrophotometer using absorbance analysis. The results showed that only microparticles with 15 and 20% (w/V) of arabic gum were able to ensure the complete protection and consequent stabilization of vitamin A, being registered the release of initial total amount of vitamin A. The usage of lower concentrations of encapsulating agent probably resulted in a non-robust network, which compromised the microparticles function. Moreover, the cumulative vitamin A release profiles obtained for all concentrations of arabic gum investigated were similar. The vitamin stability was observed for at least one month. This study proves the success of the vitamin A (retinol) microencapsulation using the spray-drying technique. (c) 2016 Elsevier B.V

Pharmaceutical/Clinical Strategies in the Treatment of Acute Promyelocytic Leukemia: All-Trans Retinoic Acid Encapsulation by Spray-Drying Technology as an Innovative Approach–Comprehensive Overview

Acute promyelocytic leukemia (APL) is phenotypically characterized by the accumulation of dysplastic promyelocytes, resulting from a cytogenetic condition due to the balanced chromosomal translocation t(15;17)(q22;q21). Current first-line treatment of APL includes all-trans retinoic acid (all-trans RA), with or without arsenic trioxide, combined with chemotherapy, and a chemotherapy-free approach wherein arsenic trioxide is used alone or in combination with all-trans RA. The usage of all-trans RA revolutionized the treatment of APL, with survival rates of 80 to 90% being achieved. The mechanism of action of all-trans RA is based on regulation of gene transcription, promoting the differentiation of leukemic promyelocytes. Encapsulation technology has been explored as an innovative strategy to overcome the major drawbacks related to the all-trans RA oral administration in the APL treatment. The most recently published works on this subject highlight the development and optimization of carrier-based delivery systems based in microparticle formulations obtained by spray-drying to be used in the treatment of APL. The ultimate goal is to obtain a controlled delivery system for RA oral administration capable of providing a slow release of this bioactive compound in the intestinal lumen

Application of Ethyl Cellulose and Ethyl Cellulose + Polyethylene Glycol for the Development of Polymer-Based Formulations using Spray-Drying Technology for Retinoic Acid Encapsulation

Ethyl cellulose (EC)-based microparticles, with and without the incorporation of polyethylene glycol (PEG) as a second encapsulating agent, were prepared using the spray-drying process for the encapsulation of retinoic acid (RA). The production of a suitable controlled delivery system for this retinoid will promote its antitumor efficiency against acute promyelocytic leukemia (APL) due to the possibility of increasing the bioavailability of RA. Product yield ranged from 12 to 28% in all the microparticle formulations, including unloaded microparticles and RA-loaded microparticles. Microparticles with a mean diameter between 0.090 ± 0.002 and 0.54 ± 0.02 µm (number size distribution) and with an irregular form and rough surface were obtained. Furthermore, regarding RA-loaded microparticles, both polymer-based formulations exhibited an encapsulation efficiency of around 100%. A rapid and complete RA release was reached in 40 min from EC− and EC + PEG-based microparticles

Characterization of biopolymer-based systems obtained by spray-drying for retinoic acid controlled delivery

Novel carrier-based delivery systems have been strategically designed and developed to beneficiate retinoic acid (RA) as medical agent. The final purpose is to deal with the factors which hamper RA efficacy (e.g. short half-life, low absorption in the intestine and severe side effects). The present work proposes the inclusion of RA into arabic gum, modified chitosan and alginic acid sodium microcapsules using spray-drying technology. The product yield varied between 26 and 38% for empty and RA-loaded microcapsules. Spherical microcapsules with a rough, slightly rough and smooth surface (according to the encapsulating agent) and with an average size in the range of 3.279 to 10.880 mu m were obtained. Controlled release studies evidenced the fastest RA release (in 99 min) for the modified chitosan formulation, while alginic acid sodium microcapsules enabled a RA release for >7 h. The main kinetic release models, based on different mathematical functions, were applied to RA. The Weibull model revealed to be the most appropriate to characterize the RA release profiles

Spray Drying Encapsulation of Elderberry Extract and Evaluating the Release and Stability of Phenolic Compounds in Encapsulated Powders

Elderberry (Sambucus nigra L.), rich in polyphenols, has recently attracted great interest in functional food, nutraceutical, and pharmaceutical industries, due to their potential health benefits to humans. However, polyphenols are very sensitive compounds and unstable. The utilisation of encapsulated polyphenols, instead of free compounds, can overcome some of their limitations. The extraction of the polyphenols from the elderberry flowers and stems was made, followed by the microencapsulation of the extract by a spray drying process. The microparticles were characterised by size, morphology, and release profile. The microencapsulated polyphenols were completely released, with total release times that range from 600 to 1140 s. The kinetic models that have a better adjustment to the practical results are the zero order, the Korsmeyer-Peppas, and the Weibull models, with correlation coefficients that range from 0.900 to 0.999. The encapsulation efficiency was similar for all the analysed particles, being the results located in a range from 92.3 to 99.8%. After 8 months of storage, the microparticles were revaluated, being possible to conclude that the elderberry microparticles present very similar release profiles comparing with the ones obtained with fresh microparticles, which proves the successful encapsulation of the elderberry extract and the stability of the microparticles over time. This experimental work leads to a very successful encapsulation of elderberry extract

Soluble vitamins (vitamin B12 and vitamin C) microencapsulated with different biopolymers by a spray drying process

Vitamins are important micronutritional compounds which are involved in many biochemical functions in the human body but are not synthesized by it; so, they have to be supplied through diet. However, vitamins are very sensitive which provoke a significant loss during the food processes and storage. So, microencapsulation can be used to minimize the loss of vitamins, to minimize the factors that interfere with their stability, to allow a controlled release process and to mask its undesirable taste, increasing their applicability In the present work, the microencapsulation of two vitamins, by a spray-drying process, was studied: vitamin B12, considering that is the most chemically complex and the largest of all the vitamins and vitamin C which is the most popular vitamin in the food industry The microparticles were prepared using a spray-dryer BUCHI B-290 (Flawil, Switzerland) with a standard 0.5 mm nozzle, under the following conditions: solution and air flow rates, air pressure and inlet temperature were set at 4 ml/min (15%); 32 m(3)/h (80%), 6.0 bar and 120 degrees C, respectively. The prepared microparticles were characterized and their physicochemical structures were analyzed by scanning electron microscopy (SEM) and by Fourier transform infrared spectroscopy (FTIR). The presence of vitamins in the microparticles was also evaluated by UV-method, validated and optimized for this objective. The evaluation of the vitamin B12 was based on absorbance values read at 361.4 nm, and for the vitamin C the absorbance was read at 260.6 nm A product yield ranging from 41.8 to 55.6% for the microparticles prepared with vitamin B12 and ranging from 43.6 to 45.4% for the microparticles formed with vitamin C was obtained and microparticles with a mean diameter around 3 mu m were observed, for all the biopolymers tested (chitosan, modified chitosan and sodium alginate). The microparticles formed with chitosan presented a very rough surface; on the other hand, the particles formed with sodium alginate or modified chitosan presented a very smooth surface. The performed tests yield significant results and prove the success of the vitamins microencapsulation This work shows that it is possible to encapsulate vitamins using different biopolymers, through a spray-drying proces

Microencapsulation of beta-galactosidase with different biopolymers by a spray-drying process

The aim of this work was to investigate the possibility of producing microparticles containing beta-galactosidase, using different biopolymers (arabic gum, chitosan, modified chitosan, calcium alginate and sodium alginate) as encapsulating agents by a spray-drying process. This study focused on the enzyme beta-galactosidase, due to its importance in health and in food processing. Encapsulation of beta-galactosidase can increase the applicability of this enzyme in different processes and applications. A series of beta-galactosidase microparticles were prepared, and their physicochemical structures were analyzed by laser granulometry analysis, zeta potential analysis, and by scanning electron microscopy (SEM). Microparticles with a mean diameter around 3 mu m have been observed, for all the biopolymers tested. The microparticles formed with chitosan or arabic gum presented a very rough surface; on the other hand, the particles formed with calcium or sodium alginate or modified chitosan presented a very smooth surface. The activity of the enzyme was studied by spectrophotometric methods using the substrate ONPG (O-nitrophenyl-beta,D-galactopyranoside). The microencapsulated beta-galactosidase activity decreases with all the biopolymers. The relative enzyme activity is 37, 20, 20 and 13%, for arabic gum, modified chitosan, calcium alginate and sodium alginate, respectively, when compared with the free enzyme activity. The enzyme microparticles formed with arabic gum shows the smallest decrease of Vmax, followed by the calcium alginate, sodium alginate, and modified chitosan

Microencapsulation of Curcumin by a Spray-Drying Technique Using Gum Arabic as Encapsulating Agent and Release Studies

Curcumin is a natural yellow pigment extracted from dried roots of turmeric, used in food applications. Despite its applicability in food products, this phenolic compound is also used in the pharmaceutical field. It is reported to have health benefits such as anticancer, antitumor, and antiviral effects. However, curcumin is a very unstable compound. Therefore, this work proposes the microencapsulation of curcumin, in order to protect it and to improve its stability and solubility in water, by spray-drying, using the gum arabic as an encapsulating agent in three different concentrations 10, 15, and 20% (weight/volume (w/v)). Emulsions were prepared with coconut oil and used to prepare the curcumin microparticles. For this purpose, different analysis and studies were performed. A product yield ranging from 44 to 52% and from 29 to 42% was obtained for the production of microparticles without and with curcumin, respectively. The curcumin microcapsules and empty capsules were characterized and evaluated. All the microparticles presented a spherical form, had a diameter around 7-9 gm (considering a volume distribution), and had a rough surface. The efficiency of encapsulation was between 75 and 85%, being higher for the particles prepared with higher concentrations of encapsulating agents. Considering the controlled release studies, the microcapsules were prepared with different concentrations of gum arabic but showed similar release profiles. However, it was also concluded that increasing the amount of gum arabic used in the formulation of the microparticles, the amount of curcumin released in the first minutes decreases; therefore, the release tends to be slower (63.2% of the release varied between 25.5 and 69.0 min). Fitting the experimental results to a linearized equation of the Weibull model, it was possible to obtain a good correlation coefficient (R-2 varying from 0.94 to 0.97), indicating that this model adapts to the experimental data obtained