Wanderley Oliveira

The present study was conducted to assess the potential of the analysis of the pressure fluctuation (PF) signals for identification of process changes in wet fluidized beds. The experiments were carried out in top spray fluidized bed equipment, with 150 mm of colu mn diameter and 500 mm height. Pressure transducers connected to a PCL711-S card (Advantech) installed in a personal computer running Labtech version 12.0 software recorded PF t ime series at a frequency of 200 Hz for 2-min intervals. Glass beads with diameters ranging fro m 425 to 600 m) were used as inert material. Experimental data of fluid izing PF signals were obtained with the feeding of distilled water, starting with the dry system. The feed was increased by 2 mL/ min each 30 minutes, and the changes in system dynamics were monitored. The bed temperature was maintained at 50 o C. In general, PF signals changed due to the introduction of liquid feeds. Determination of the power spectral density (PSD) and autocorrela...

We undertook the present study to evaluate the activity of the dried extract of Maytenus ilicifolia against stomach ulcers and in the increase of the volume and pH of the gastric juice of Wistar rats, as a model to evaluate the viability of the Jet Spouted Bed Dryer for the production of dry-extracts of medicinal Brazilian plants. The extract was obtained from the drying of a hydro-alcoholic extract with drying aid (40% of colloidal SiO2 related to solid content in the concentrated extract, at a concentration of 15.82% in water). The drying conditions employed were: Temperature of the spouting gas 150 degrees C, feed flow-rate of hydro-alcoholic extract 16.0 g/min, feed flow rate of the spouting gas 1.67 m3/min and static bed height 7.0 cm. Wistar rats received three different doses (140, 280 and 420 mg/kg) of the dried extract by intraperitoneal way and, after 60 minutes, were immobilized with wire screen and placed at temperature of 4 degrees C for two hours (cold-restraint stress...

Clove (Syzygium aromaticum) is one of the most valuable spices that has been used for centuries as food preservative and for many medicinal purposes. Clove is native of Indonesia but nowadays is cultured in several parts of the world including Brazil in the state of Bahia. This plant represents one of the richest source of phenolic compounds such as eugenol, eugenol acetate and gallic acid and posses great potential for pharmaceutical, cosmetic, food and agricultural applications. This review includes the main studies reporting the biological activities of clove and eugenol. The antioxidant and antimicrobial activity of clove is higher than many fruits, vegetables and other spices and should deserve special attention. A new application of clove as larvicidal agent is an interesting strategy to combat dengue which is a serious health problem in Brazil and other tropical countries. Pharmacokinetics and toxicological studies were also mentioned. The different studies reviewed in this w...

ABSTRACT In the present study surfactant mediated extraction has been investigated for the extraction of antioxidants from clove flower buds (Syzygium aromaticum). The advantage of this technique is the replacement of organic solvents or other toxic substances by surfactants that could be part of a formulation. The influence of the Hydrophilic Lipophylic Balance (HLB) on extraction was examined in the range of 4.3 to 15 by the mixture of two commonly used surfactants in pharmaceutical and food applications (Tween 80 and Span 80). The effect of the surfactant concentration (2, 5, and 10%) was also evaluated. Results showed that higher HLB values improved eugenol and polyphenols extraction, which could be correlated with the in vitro antioxidant activity. Surfactant concentration of 5% (w/w) showed to be more effective than 2% and there were no significant differences between the results obtained at concentrations of 5 and 10%. The effect of the pH was also investigated on Tween 80 solutions and results showed that increases on the pH value improved the eugenol extraction.

Abstract Two simple procedures for the preparation of magnetic chitosan enzyme microparticles have been investigated and used for the immobilisation of endophytic fungus Cercospora kikuchii lipase as model enzyme. In the first case, lipase was entrapped in Fe3O4-chitosan microparticles by cross-linking method, while in the second case magnetic immobilised derivatives were produced using spray drying. Immobilised enzymes showed high enzyme activity retention and stability during storage without significant loss of activity. Glutaraldehyde Fe3O4-chitosan powders presented a higher lipase activity retention and storage stability than the others preparations. However, the immobilised derivatives produced by cross-linking showed higher enzyme activity after reuse cycles. The results proved that the magnetic Fe3O4-chitosan microparticles are an effective support for the enzyme immobilisation since the immobilised lipase showed best properties than the free form.

ABSTRACT This work studied the immobilization of Cercospora kikuchii lipases on chitosan microparticles by chemical attachment on chitosan acetate microparticles activated by glutaraldehyde (CAM) added before or after the enzyme and physical adsorption on highly deacetylated chitosan hydrochloride microparticles (CHM). Lipases covalently immobilized on pre-activated CAM showed better performance retaining 88.4% of the enzymatic activity, with 68.2% of immobilization efficiency (IE). The immobilized enzyme retained an activity of about 53.5 % after five reuses, using p-NPP as substrate. Physical adsorption of lipase onto highly deacetylated CHM showed 46.2 % of enzymatic activity and 28.6% of IE. This immobilized derivative did not lose activity up to 80 days of storage at 4°C, while lipases immobilized on pre-activated CAM maintained its activity up to 180 days at same conditions. Taken together the results indicate that chitosan microparticles provide an optimal microenvironment for the immobilized enzyme to maintain good activity and stability.

ABSTRACT This work aims to investigate the feasibility of fluidised beds for seed agglomeration of rosemary (Rosmarinus officinalis) extract compositions, attempting to form a product with adequate pharmacotechnical and physicochemical properties. Lipid- and carbohydrate-based compositions with different viscosities were top sprayed onto fluidised beds of cassava flour or sugar pellets as seed particles. The compositions used were also spray-dried to compare the physicochemical properties of the product generated by the two processes. The viscosity of the feed formulations influenced the efficiency of the coating/agglomeration and the agglomeration percentage of the granules. Fluidised bed granules exhibited higher efficiency of coating/agglomeration, higher retention of bioactive compounds and better flow properties than the powder obtained by spray drying.

ABSTRACT Spray drying is a technique commonly used to produce powdered phytopharmaceutical ingredients from medicinal plants. Product quality is related to operating conditions and the drying carriers used. Bidens pilosa L. is a South American plant with proved antiinflamatory, antimalaric, antitumoral and hepatoprotector activities. The aim of this work was to optimise the processing variables inlet drying temperature, plant extract feed flow rate and drying composition on the properties of the powdered B.pilosa compositions. Experimental planning, regression and multiple response were used in data analysis and to optimize the drying conditions. The responses evaluated were total flavonoid content, antioxidant activity, concentration of selected plant compounds, particle size, residual moisture content, solubility, flow properties, product recovery and drying efficiency. Results showed that inlet drying temperature was the factor that showed significant influence in most of the responses. The concentration of the bioactive marker compounds monitored decrease conversely with inlet spray drying temperature. Powders obtained at low inlet drying temperatures presented higher residual moisture and particle size, favouring flow properties. The optimized conditions based on the mathematical models fitted to experimental data were: Aerosil®:Cellulose 13:37%, extract feed rate 8.95 mg/min and inlet gas temperature of 155.2 °C.

ABSTRACT The total flavonoid content (TFC), total polyphenols content (TPC), and in vitro antioxidant activity (AA) of six Bidens pilosa L., Asteraceae, populations harvested from different localities were evaluated in this work. The plants were separated in roots, stems, and leaves/flowers, and the influence of extraction methods was investigated.Areversed-phase high-performance liquid chromatography method (HPLC) was developed and employed to obtain characteristic HPLC fingerprints of the bioactive compounds present in the extractive solutions, which were correlated with the TFC, TPC, and AA. Extractive solutions of leaves/flowers presented a higher AA when compared with those obtained from other parts of the plant (IC50 of 35.35±0.10 µg/mL). The stem extracts presented the lowest AA (IC50 117.2±1.96 µg/mL). A direct correlation of AA with TFC and TPC was evidenced. The highest AA was obtained by dynamic maceration and was statistically different from the AA presented by the extractive solutions obtained by other extraction methods. The results of this work evidenced differences that can be found at different stages of development of phytopharmaceutical preparations from B. pilosa and highlighted the importance of using the concentration of marker compounds as well as HPLC fingerprints as quality control parameters.

ABSTRACT In this study, the spouted bed performance during drying of an extract of the aromatic plant Lippia sidoides has been investigated. The effects of the several processing variables, namely the inlet temperature of the spouting gas (Tge), the feed flow rate of the extract relative to the maximum dryer evaporation capacity (Ws/Wmax), the percentage of drying carrier (Adj), and the percentage of colloidal silicon dioxide added to feed composition (SiO2), on equipment performance and product properties were investigated by using a four-factor and three-level Box–Behnken design. Product recovery (R), product accumulation in the bed (Ac), thermal efficiency (η), loss on drying (LD), product moisture content (Xp), water activity (Aw), polyphenol degradation ratio (DPF), and mean powder diameter (dpm) were the responses evaluated. Results demonstrated significant effects of Ws/Wmax, SiO2, and Adj on spouted bed drying performance. Product properties were affected by all variables studied. Feasibility of the spouted bed technology for the dehydration of L. sidoides extract and the product properties depend on the feed composition properties and drying conditions. The spouted bed showed drying performance and product properties that were comparable to the ones obtained in a lab-scale spray dryer.

Microbial enzymes have been used for various biotechnological applications; however, enzyme stabilization remains a challenge for industries and needs to be considered. This study describes the effects of spray-drying conditions on the activity and stability of β-fructofuranosidase from Fusarium graminearum. The extracellular enzyme β-fructofuranosidase was spray dried in the presence of stabilizers, including starch (Capsul) (SC), microcrystalline cellulose (MC), trehalose (TR), lactose (LC) and β-cyclodextrin (CD). In the presence of TR (2% w/v), the enzymatic activity was fully retained. After 1 year of storage, 74% of the enzymatic activity was maintained with the CD stabilizer (10% w/v). The residual activity was maintained as high as 80% for 1 h at 70°C when MC, SC and CD (5% w/v) stabilizers were used. Spray drying with carbohydrates was effective in stabilizing the F. graminearum β-fructofuranosidase, improved enzymatic properties compared to the soluble enzyme and demonstrated a potential use in future biotechnology applications.

ABSTRACT The aim of this work was to investigate the effects of drying parameters on the retention of the enzymatic activity and on the physical properties of spray-dried pineapple stem extract. A Box and Behnken experimental design was used to investigate the effects of the processing parameters on the product properties. The parameters studied were the inlet temperature of drying gas (Tgi), the feed flow rate of the pineapple extract relative to evaporative capacity of the system (Ws /Wmax), and the concentration of maltodextrin added to the extract (MD). Significant effects of the processing parameters on the retention of the proteolytic activity of the powdered extract were observed. High processing temperatures lead to a product with a smaller moisture content, particle size, and lower agglomerating tendency. A product with insignificant losses of the proteolytic activity (≈ 10%) and low moisture content (less than 6.5%) is obtained at selected conditions.

ABSTRACT The microencapsulation of Lippia sidoides extracts in blends of carbohydrates was investigated. The extraction conditions were determined through a 22 factorial design. The effects of the plant:solvent ratio (A – 7.5:100 and 15:100 m/m) and the extraction time (B – 30 and 90 min) on thymol content of extractive solutions were evaluated, using a 2:1 (v/v) of ethanol:water at a temperature of 50 °C, as a solvent system. The selected extract was subjected to spray drying. Blends of maltodextrin and gum arabic at different proportions (4:1; 3:2; 2:3; 0:1) (m/m) were used as encapsulating material. The protective effects of the maltodextrin and gum arabic blends were evaluated by determination of the thymol retention in the dried product, which ranged from 70.2 to 84.2% (related to the content in the extractive solution). An increase in the gum arabic to maltodextrin (DE10) ratio has positive effect on thymol retention. L. sidoides extracts and spray-dried products showed antifungal activity against tested fungal strains (Candida albicans – ATCC 64548, Candida glabrata – ATCC 90030, Candida krusei – ATCC 6258, and Candida parapsilosis – ATCC 22019), evidencing their potential as a natural antifungal agent for medicinal, food, and cosmeceutical purposes.

ABSTRACT Usually immobilization is a requirement for the use of enzymes as an industrial biocatalyst. In this work, endophytic fungus Cercospora kikuchii lipase was immobilized by covalent binding on agricultural by-products and microcrystalline cellulose. The enzyme support system was submitted to spouted bed drying. Lipase immobilized on microcrystalline cellulose with 1.5% of glutaraldehyde showed the best results, presenting 179.1% of the original activity after drying, followed by rice husk (173.9%), corn stover (169.8%), sugarcane bagasse (157.3%), green coconut fiber (102.3%), and corncob (99.8%). The immobilized derivatives obtained showed a decreased enzyme activity with an average of only 17.31%, whereas the enzyme in its free form lost 85.8% of its initial activity after storage for 6 months. The operational stability showed that the biocatalysts prepared retained an average of 67.2% of the initial activity after five reuse cycles. The results showed that the use of agricultural by-products as low-cost support material associated with the spouted bed drying is promising and can contribute to industrial application of biocatalysts.

The present work deals with improving the production and stabilization of lipases from Cercospora kikuchii. Maximum enzyme production (9.384 U/ml) was obtained after 6 days in a medium supplemented with 2% soybean oil. The lipases were spray dried with different adjuvants, and their stability was studied. The residual enzyme activity after drying with 10% (w/v) of lactose, β-cyclodextrin, maltodextrin, mannitol, gum arabic, and trehalose ranged from 63 to 100%. The enzyme activity was lost in the absence of adjuvants. Most of the adjuvants used kept up at least 50% of the enzymatic activity at 5°C and 40% at 25°C after 8 months. The lipase dried with 10% of β-cyclodextrin retained 72% of activity at 5°C. Lipases were separated by butyl-sepharose column into 4 pools, and pool 4 was partially purified (33.1%; 269.5 U/mg protein). This pool was also spray dried in maltodextrin DE10, and it maintained 100% of activity.

This article presents an overview of relevant issues to be considered in the development of standardized phytochemical preparations, focusing on the use of the spouted bed as a drying method. Aspects related to the effects of feed composition properties and processing parameters on system performance and product quality are addressed.From the information presented, it can be concluded that the spouted

Microparticles of ketoprofen entrapped in blends of acrylic resins (Eudragit RL 30D and RS 30D) were successfully produced by spray drying. The effects of the proportion ketoprofen : polymer (1:1 and 1:3) and of spray-drying parameters (drying gas inlet temperatures of 80 and 100°C; microencapsulating composition feed flow rates of 4 and 6 g/min) on the microparticles properties (drug content, encapsulation

The objective of this work was to study the dissolution process of sodium diclofenac granules coated with a polymeric suspension of Eudragit L-30D-55 by fluidized bed. Methacrylic acid-methylmetacrylate copolymer, also known as Eudragit, has been used as a pH sensitive coating material to protect drug substances prior to delivery to the human intestines. The sodium diclofenac granules were prepared by wet granulation technology using microcrystalline cellulose (MICROCEL), sodium diclofenac, and polivinilpirrolidone K-30. The granules coating operation was carried out in a fluidized bed with top spraying by a double-fluid nozzle. The dissolutions studies of the coated granules were performed in triplicate in a dissolution test station according to USP XXIII (1995) "in vitro testing requirements" Method A (paddle method, rotation of 100 RPM and temperature fixed at 37 degrees C). The dissolution mediums were 0.1N HCl solution and a pH 6.8 phosphate buffer solution, following the pH change dissolution procedure specified in USP for enteric-coated articles: 2 h of exposure to 750 mL of 0.1N HCl followed by testing in 1000 mL of pH 6.8 phosphate buffer, the pH being adjusted with 250 mL of 0.2 M tribasic sodium phosphate solution. The released amount of sodium diclofenac was periodically determined by UV spectrophotometry at wavelength of 276 nm, using a spectrophotometer UV-VIS HP 8453. The coated product showed gastric resistance properties confirming the feasibility of the fluidized bed for applying enteric coating in granules and pharmaceutical powders.

... the herbal extract were quantified by determination of the surface tension, rheological properties, density, pH ... The chemical composition of the concentrated extract was determined by the analyti-cal ... The rheology of the herbal extract preparations with and without the presence of ...

ABSTRACT This work evaluates the feasibility of the draft-tube spouted bed for drying of herbal extract. Drying runs were carried out according to a central composite design in a conical–cylindrical draft-tube spouted bed. The variables studied were the percentage of the drying aid (ADJ), the drying gas flow rate relative to gas flow at minimum spouting (Q/Qms), and the flow rate of extract fed to the system relative to the spouting gas flow rate (Ws/Wg). Colloidal silicon dioxide was the drying aid used in order to improve drying performance. Statistical analysis of the effects of processing parameters on product recovery, product accumulation in the bed, and product properties permitted the identification of parameters presenting significant effects on drying. Optimized drying conditions were related to experimental parameters as follow: high levels of the percentage of drying adjuvant (ADJ), high airflow rate relative to minimum spouting (Q/Qms), and low values of the feed flow rate of the extract relative to the gas flow rate (Ws/Wg). Cet exposé évalue la faisabilité d'utiliser un lit jaillissant à tube d'aspiration pour assécher les extraits d'herbes. Les séquences de séchage ont été effectuées en fonction d'une conception composite centrale dans un lit jaillissant conique-cylindrique à tube d'aspiration. Les variables étudiées étaient le pourcentage d'adjuvant de séchage (ADJ), le débit de gaz asséchant par rapport au débit de gaz au jaillissement minimum (Q/Qms), le taux de débit de l'extrait alimenté dans le système comparativement au débit du gaz jaillissant (Ws/Wg). Le dioxyde de silicium colloïdal a été utilisé comme adjuvant de séchage afin d'améliorer la performance du séchage. L'analyse statistique des effets des paramètres de traitement sur l'extraction du produit, l'accumulation dans le lit, et les propriétés du produit ont permis l'identification de paramètres ayant un impact significatif sur le séchage. Les conditions de séchage optimales étaient liées aux paramètres expérimentaux comme suit: pourcentage élevé d'adjuvant de séchage (ADJ), taux d'écoulement d'air élevé par rapport au jaillissement minimum (Q/Qms), et faibles valeurs du taux d'écoulement d'alimentation de l'extrait par rapport au taux d'écoulement du gaz (Ws/Wg).

ABSTRACT The feasibility of detecting instability in wet spouted beds via pressure fluctuation (PF) time-series analyses was investigated. Experiments were carried out in a cylindrical Plexiglas column of diameter 150 mm with a conical base of internal angle 60°, an inlet orifice diameter of 25 mm and glass beads of diameter 2.4 mm. Transducers at several axial positions measured PF time series with incremental addition of aqueous sucrose solutions of different concentrations. Liquid addition affected the spouted bed dynamics, causing irregular spouting, increased voidage in the annulus, increased fountain height, irregular annulus height, channelling, agglomeration, and adhesion of particles to the column walls. Autocorrelations indicated the appearance of periodicities in the PF signals with increasing sucrose addition. Dominant peaks in power-spectral density developed at low frequencies with changing system dynamics. The results indicate that PF signals furnish relevant information on system dynamics, useful for monitoring and control of spouted bed operations such as particle coating and drying of paste-like materials.La faisabilité de déceler l'instabilité dans des lits jaillissants humides par l'analyse de séries chronologiques de fluctuations de pression a été étudiée. Des expériences ont été menées dans une colonne de Plexiglas cylindrique ayant un diamètre de 150 mm et une base conique ayant un angle interne de 60°, un orifice d'entrée d'un diamètre de 25 mm et des billes de verre d'un diamètre de 2,4 mm. Des transducteurs placés à diverses positions axiales mesuraient les séries chronologiques de fluctuations de pression avec ajout incrémentiel de solutions de saccharose aqueux à différentes concentrations. L'ajout de liquide a affecté la dynamique du lit jaillissant, causant un jet irrégulier, une augmentation du degré de vide dans l'espace annulaire, une augmentation de la hauteur de la fontaine, une hauteur irrégulière de l'espace annulaire, un cheminement préférentiel, une agglomération et l'adhésion des particules aux parois de la colonne. Les autocorrélations ont indiqué l'apparition de périodicités dans les signaux FP avec l'ajout additionnel de saccharose. Des pics dominants dans la densité spectrale de puissance sont apparus à basses fréquences avec le changement de la dynamique du système. Les résultats indiquent que les signaux FP donnent des renseignements pertinents sur la dynamique du système, utiles pour le suivi et le contrôle des opérations des lits jaillissants telles que l'enrobage des particules et le séchage de matériaux de type pâte.

ABSTRACT In this work the storage stability of a Maytenus ilicifolia phytopharmaceutical preparation produced by spouted bed drying was investigated. Powder samples of M. ilicifolia extracts were submitted to stress storage conditions at temperatures of 25, 34 and 45°C and relative humidities of 32.4% and 63.5%. The effect of the storage conditions on the physical and chemical properties of the product were evaluated through total polyphenols, tannin and catechin determination, moisture content, macroscopic changes in powder appearance and X-ray difractograms. The results showed that high storage temperature and high relative humidity lead to increased degradation of the bioactive marker compounds. The shelf life of the spouted bed dried extracts was 276.2 days when the powder is stored at 25°C and 32.4% relative humidity.

ABSTRACT Hydrodynamic studies were conducted in a semi-cylindrical spouted bed column of diameter 150 mm, height 1000 mm, conical base included angle of 60° and inlet orifice diameter 25 mm. Pressure transducers at several axial positions were used to obtain pressure fluctuation time series with 1.2 and 2.4 mm glass beads at U/Ums from 0.3 to 1.6, and static bed depths from 150 to 600 mm. The conditions covered several flow regimes (fixed bed, incipient spouting, stable spouting, pulsating spouting, slugging, bubble spouting and fluidization). Images of the system dynamics were also acquired through the transparent walls with a digital camera. The data were analyzed via statistical, mutual information theory, spectral and Hurst's Rescaled Range methods to assess the potential of these methods to characterize the spouting quality. The results indicate that these methods have potential for monitoring spouted bed operation.