Effects of different spray formulations on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females detached from experimentally infested cattle

This present study aimed to evaluate the deleterious effects of some commercially available spray formulations (15% Cypermethrin+25% Chlorpyriphos+1% Citronellal and 8% Cypermethrin+60% Ethion) on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females that detached from experimentally infested cattle. The following reproductive parameters of engorged female ticks were analyzed: female weight, egg mass weight, percentage of hatchability, percentage of reduction in oviposition, percentage of reduction in hatchability, reproductive efficiency and percent control/efficacy of formulations for reproductive parameters. Our findings showed that although the strain R. (B.) microplus used in both experiments was thought to be sensitive to the test compounds because of the acaricidal efficacy observed throughout these trials, it was not possible to observe overall deleterious effects on the reproductive parameters of this tick species with both spray formulations. However, the 8% Cypermethrin+60% Ethion showed short-term significant effects on the weight of female ticks between the 14th and 16th days post-treatment and the weight of female and the egg mass weight between the 20th and 22nd days post-treatment. New studies should be conducted to show if these results regarding the reproductive parameters of fully engorged R. (B.) microplus females, combined with the acaricidal efficacy can be sufficient to reduce the number of chemical treatments administered to cattle.

In-season calcium-spray formulations improve calcium balance and fruit quality traits of peach.

Experiments to evaluate the effect of in-season calcium (Ca) sprays on late-season peach (Prunus persica L. Batsch cv. Calrico) were carried out for a 2-year period. Calcium formulations (0.5% and 1.0% in 2008 and only 0.5% tested in 2009) supplied either as CaCl2 or Ca propionate in combination with two or three adjuvants (0.05% of the nonionic surfactants Tween 20 and Break Thru, and 0.5% carboxymethylcellulose, CMC) were sprayed four to five times over the growing season. Peach mesocarp and endocarp Ca concentrations were determined on a 15-day basis from the beginning of May until the end of June. Further tissue analyses were performed at harvest. A decreasing trend in fruit Ca concentrations over the growing season was always observed regardless of the Ca treatments. Both in 2008 and 2009, significant tissue Ca increments associated with the application of Ca-containing sprays in combination with adjuvants were only observed in June, which may be coincident with the period of pit hardening. In 2008, both at harvest and after cold storage, the total soluble-solids concentration (° Brix) of fruits supplied with Ca propionate (0.5% and 1.0% Ca) was always lower as compared to the rest of treatments. The application of multiple Ca-containing sprays increased firmness at harvest and after cold storage, especially when CaCl2 was the active ingredient used. Supplying the adjuvants Tween 20 and CMC increased fruit acidity both at harvest and after cold storage. Evaluation of the development of physiological disorders after cold storage (2 weeks at 0°C) indicated a lower susceptibility of Ca-treated fruits to internal browning. Fruits treated with multiple CaCl2-, CMC-, and Break Thru®-containing sprays during the growing season were significantly less prone to the development of chilling injuries as compared to untreated peaches.

Towards a model of spray-canopy interactions : interception, shatter, bounce and retention of droplets on horizontal leaves

Pesticides used in agricultural systems must be applied in economically viable and environmentally sensitive ways, and this often requires expensive field trials on spray deposition and retention by plant foliage. Computational models to describe whether a spray droplet sticks (adheres), bounces or shatters on impact, and if any rebounding parent or shatter daughter droplets are recaptured, would provide an estimate of spray retention and thereby act as a useful guide prior to any field trials. Parameter-driven interactive software has been implemented to enable the end-user to study and visualise droplet interception and impaction on a single, horizontal leaf. Living chenopodium, wheat and cotton leaves have been scanned to capture the surface topography and realistic virtual leaf surface models have been generated. Individual leaf models have then been subjected to virtual spray droplets and predictions made of droplet interception with the virtual plant leaf. Thereafter, the impaction behaviour of the droplets and the subsequent behaviour of any daughter droplets, up until re-capture, are simulated to give the predicted total spray retention by the leaf. A series of critical thresholds for the stick, bounce, and shatter elements in the impaction process have been developed for different combinations of formulation, droplet size and velocity, and leaf surface characteristics to provide this output. The results show that droplet properties, spray formulations and leaf surface characteristics all influence the predicted amount of spray retained on a horizontal leaf surface. Overall the predicted spray retention increases as formulation surface tension, static contact angle, droplet size and velocity decreases. Predicted retention on cotton is much higher than on chenopodium. The average predicted retention on a single horizontal leaf across all droplet size, velocity and formulations scenarios tested, is 18, 30 and 85% for chenopodium, wheat and cotton, respectively.

A comparison of three different methodologies for evaluating Rhipicephalus (Boophilus) rnicroplus susceptibility to topical spray compounds

This study aimed to compare three different methodologies (Adult Immersion Tests, field trials with naturally infected animals, and a Stall Test using artificially infested cattle) to evaluate the efficacy of two topical formulations that we administered as whole body sprays (15% Cypermethrin + 30% Chlorpyriphos + 15% Fenthion-Colosso (R) FC 30, Ouro Fino Agronegocios; and 60% Dichlorvos + 20% Chlorpyriphos-Ectofos (R), Vallee Saude Animal Ltd.), against a susceptible strain of Rhipicephalus (Boophilus) microplus. To achieve this objective, two natural infestation trials were conducted, as well as two artificial infestation trials (Stall Tests) and two Adult Immersion Tests (AIT). The AIT results showed that both spray formulations achieved 100% efficacy against R. (B.) micro plus fully engorged females. However, when observing results obtained by field trials (natural infestations) and Stall Tests, none of these topically applied compounds reached 100% efficacy or affected the reproductive capacity of the fully engorged female ticks. Additional studies must be conducted to compare these in vivo methodologies with different in vitro techniques, such as the Larval Packet Test. However, based on results obtained here, we can conclude that depending on the spray formulations used, the AIT can overestimate acaricidal efficacy and values of reproductive efficiency of such compounds against R (B.) micro plus. Specifically, when dealing with spray formulations in the Stall Tests, the period of residual action can increase because these animals are sheltered from contact with environmental factors that might interfere with the efficacy of the products tested. It may be necessary to take in vivo trial results into consideration (such as field trials with naturally infested animals or Stall Tests) to standardize a specific in vitro assay, such as the Adult Immersion Test. (C) 2014 Elsevier B.V. All rights reserved.

Effect of a spray formulation on the reproductive parameters of a susceptible population of Rhipicephalus (Boophilus) microplus

The number of studies emphasizing the possible damage that acaricidal spray formulations can cause on engorged female ticks'reproductive parameters is small. The present study evaluated the deleterious effects of a spray formulation (dichlorvos 60% + chlorpyrifos 20%) on the reproductive parameters of a susceptible population of Rhipicephalus (B.) microplus females, using the Stall Test. The ticks were allocated randomly to treatments according to the mean numbers of females detached from each cow on days -3, -2 and -1 and the cattle pen location. The numbers of engorged female ticks that naturally detached from the cattle were counted daily from day 1 to day 30. For each group, 20 detached engorged female ticks or the available number collected daily were evaluated regarding reproductive parameters. Associations of organophosphates demonstrated elevated acaricidal efficacy, as well as deleterious effects on the reproductive parameters of R. (B.) microplus females. The engorged female weight (days 1 to 7), weight of egg masses (days 5 to 10) and larval hatching percentage (days 5 to 19) were decreased (P <= 0.05). It is possible that a formulation can lead to deleterious effects on R. (B.) microplus females when the tick population analyzed shows elevated sensitivity towards a particular formulation. However, further studies need to be conducted.

Comparison of a novel spray congealing procedure with emulsion-based methods for the micro-encapsulation of water-soluble drugs in low melting point triglycerides

The particle size characteristics and encapsulation efficiency of microparticles prepared using triglyceride materials and loaded with two model water-soluble drugs were evaluated. Two emulsification procedures based on o/w and w/o/w methodologies were compared to a novel spray congealing procedure. After extensive modification of both emulsification methods, encapsulation efficiencies of 13.04% tetracycline HCl and 11.27% lidocaine HCl were achievable in a Witepsol (R)-based microparticle. This compares to much improved encapsulation efficiencies close to 100% for the spray congealing method, which was shown to produce spherical particles of similar to 58 mu m. Drug release studies from a Witepsol (R) formulation loaded with lidocaine HCl showed a temperature-dependent release mechanism, which displayed diffusion-controlled kinetics at temperatures similar to 25 degrees C, but exhibited almost immediate release when triggered using temperatures close to that of skin. Therefore, such a system may find application in topical semi-solid formulations, where a temperature-induced burst release is preferred.

Investigation Into The Effect of Varying L-leucine Concentration on the product characteristics of Spray-dried Liposome Powders

Spray-dried formulations offer an attractive delivery system for administration of drug encapsulated into liposomes to the lung, but can suffer from low encapsulation efficiency and poor aerodynamic properties. In this paper the effect of the concentration of the anti-adherent l-leucine was investigated in tandem with the protectants sucrose and trehalose. Two manufacturing methods were compared in terms of their ability to offer small liposomal size, low polydispersity and high encapsulation of the drug indometacin. Unexpectedly sucrose offered the best protection to the liposomes during the spray drying process, although formulations containing trehalose formed products with the best powder characteristics for pulmonary delivery; high glass transition values, fine powder fraction and yield. It was also found that l-leucine contributed positively to the characteristics of the powders, but that it should be used with care as above the optimum concentration of 0.5% (w/w) the size and polydispersity index increased significantly for both disaccharide formulations. The method of liposome preparation had no effect on the stability or encapsulation efficiency of spray-dried powders containing optimal protectant and anti-adherent. Using l-leucine at concentrations higher than the optimum level caused instability in the reconstituted liposomes.

The effect of polymer coatings on physicochemical properties of spray-dried liposomes for nasal delivery of BSA

This work describes the development of spray dried polymer coated liposomes composed of soy phosphatidylcholine (SPC) and phospholipid dimyristoyl phosphatidylglycerol (DMPG) coated with alginate, chitosan or trimethyl chitosan (TMC), that are able to penetrate through the nasal mucosa and offer enhanced penetration over uncoated liposomes when delivered as a dry powder. All the liposome formulations, loaded with BSA as model antigen, were spray-dried to obtain powder size and liposome size in a suitable range for nasal delivery. Although coating resulted in some reduction in encapsulation efficiency, levels were still maintained between 60% and 69% and the structural integrity of the entrapped protein and its release characteristics were maintained. Coating with TMC gave the best product characteristics in terms of entrapment efficiency, glass transition (Tg) and mucoadhesive strength, while penetration of nasal mucosal tissue was very encouraging when these liposomes were administered as dispersions although improved results were observed for the dry powders

Spray-dried polysaccharide microparticles aimed at pulmonary delivery of antitubercular drugs

Dissertação de mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2015

Assessment of production efficiency, physicochemical properties and storage stability of spray-dried chlorophyllide, a natural food colourant, using gum Arabic, maltodextrin and soy protein isolate-based carrier systems

P>The aim of this research was to study spray drying as potential action to protect chlorophyllide from environmental conditions for shelf-life extension and characterisation of the powders. Six formulations were prepared with 7.5 and 10 g of carrier agents [gum Arabic (GA), maltodextrin (MA) and soybean protein isolate (SPI)]/100 mL of chlorophyllide solutions. The powders were evaluated for morphological characteristics (SEM), particle size, water activity, moisture, density, hygroscopicity, cold water solubility, sorption isotherms, colour and stability, during 90 days. All the powders were highly soluble, with solubility values around 97%. A significant lower hygroscopicity was observed for GA powders, whilst the lower X(m) values obtained by GAB equation fitting of the sorption isotherms was observed for the 7.5 g MA/100 mL samples. All formulations, but the 1 (7.5 g SPI/100 mL of chlorophyllide), provided excellent stability to the chlorophyllide during 90 days of storage even at room temperature.

The use of spray drying technology to reduce bitter taste of casein hydrolysate

The utilization of protein hydrolysates in food systems is frequently hindered due to their bitterness and hygroscopicity. Spray drying technology could be an alternative for reducing these problems. The aim of this work was to reduce or to mask the casein hydrolysate bitter taste using spray drying and mixtures of gelatin and soy protein isolate (SPI) as carriers. Six formulations were studied: three with 20% of hydrolysate and 80% of mixture (gelatine/SPI at proportions of 50/50, 40/60 and 60/40%) and three with 30% of hydrolysate and 70% of mixture (gelatine/SPI at proportions of 50/50, 40/60 and 60/40%). The spray-dried formulations were evaluated by SEM, hygroscopicity, thermal behavior (DSC), dissolution, and bitter taste, by a trained sensory panel using a paired-comparison test (free samples vs. spray-dried samples); all samples were presented in powder form. SEM analysis showed mostly spherically shaped particles, with many concavities and some particles with pores. All formulations were oil and water compatible and showed lower hygroscopicity values than free casein hydrolysate. At Aw 0.83, the free hydrolysate showed Tg about 25 degrees C lower than the formulations, indicating that the formulations may be more stable at Aw >= 0.65 since the glass transition should be prevented. The sensory panel found the formulations, tasted in the powder form, to be less bitter (P < 0.05) than the free casein hydrolysate. These results indicated that spray drying of casein hydrolysate with mixtures of gelatin and SPI was successful to attenuate the bitterness of casein hydrolysate. Thus, spray drying widens the possibilities of application of casein hydrolysates. (C) 2009 Elsevier Ltd. All rights reserved.

Choice of tracers for the evaluation of spray deposits

As substâncias traçadoras são usadas para avaliar a eficácia de pulverizações mas, normalmente, elas modificam a tensão superficial de soluções aquosas. O trabalho objetivou definir um método para avaliar a distribuição e a quantidade de produto depositada em pulverizações, utilizando-se substâncias traçadoras, com a possibilidade de ajustar a tensão superficial da calda. Foram testados os produtos Azul Brilhante a 0,15%, Saturn Yellow a 0,15% suspenso em lignosulfonato Vixilperse a 0,015% e a Fluoresceína Sódica a 0,005%, e as misturas de Azul Brilhante mais Saturn Yellow e Azul Brilhante mais Fluoresceína, nas mesmas concentrações. Para avaliar a degradação as soluções com os produtos foram depositados sobre folhas de citros e avaliados as quantidades através da leitura de unidade de fluorescência e densidade óptica, das soluções sem secar, secas no escuro, exposta ao sol por 2, 4 e 8 horas e comparadas com as leituras obtidas com os depósitos direto em água. A tensão superficial da solução traçadora foi determinada pela passagem de gotas formadas no período entre 20 e 40 segundos. A mistura do Azul Brilhante mais o Saturn Yellow a 0,15%, não apresentou degradação em todas as condições de avaliação, não foi absorvida pelas folhas e manteve a solução na mesma tensão superficial da água, possibilitando ajustá-la aos mesmos níveis das concentrações dos produtos fitossanitários. Isto proporcionou o estabelecimento de um método qualitativo pela avaliação visual sobre luz ultravioleta da distribuição do pigmento e quantitativo com a determinação da quantidade depositada do corante numa mesma solução, em diferentes tensões superficiais na calda de pulverização.

Influence of alternative drying aids on water sorption of spray dried mango mix powders: a thermodynamic approach

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microparticulated Hydrochlorothiazide Solid Dispersion: Enhancing Dissolution Properties via Spray Drying

The aim of the present study was to obtain microparticles of hydrochlorothiazide, a diuretic drug that practically insoluble in water, by spray drying and to investigate the influence of process parameters using a three-level, three-factor Box-Behnken design. Process yields, moisture content, particle size, flowability, and solubility were used to evaluate the spray-dried microparticles. The data were analyzed by response surface methodology using analysis of variance. The independent variables studied were outlet temperature, atomization pressure, and drug content. The formulations were prepared using polyvinylpyrrolidone and colloidal silicon dioxide as the hydrophilic carrier and drying aid, respectively. The microparticle yield ranged from 18.15 to 59.02% and resulted in adequate flow (17 to 32 degrees), moisture content between 2.52 to 6.18%, and mean particle size from 45 to 59 mu m. The analysis of variance showed that the factors studied influenced the yields, moisture content, angle of repose, and solubility. Thermal analysis and X-ray diffractometry evidenced no drug interactions or chemical modifications. Photomicrographs obtained by scanning electron microscopy showed spherical particles. The solubility and dissolution rates of hydrochlorothiazide were remarkably improved when compared with pure drug. Therefore, the results confirmed the high potential of the spray-drying technique to obtain microparticulate hydrochlorothiazide with enhanced pharmaceutical and dissolution properties.

Particle engineering for the production of respirable dry powder formulations

Hyaluronan (HA) plays an important role in lung pathophysiology. For this reason it has attracted great attention both as active ingredient and as excipient in treating lung diseases by direct pulmonary HA administration. The aim was the production of highly respirable and flowable HA powders either as a potential carrier for drug delivery or for being delivered directly by inhalation. Engineered sodium hyaluronate powders were produced by spray-drying technique. All the spray-dried powders were characterised in terms of particle size distribution, drug content, morphology and in vitro respirability. HA was successfully formulated with salbutamol sulphate in combination with leucine and highlighted remarkable aerodynamic performance (emitted dose equal to 83 % and FPF % equal to 97.1%). Moreover, HA colloidal solutions were designed and they were spray-dried. In order to improve particle aerodynamic characteristics, different types of excipients were investigated. In particular, stearylamine (5% w/w) allowed to obtain the best performance throughout the experimental set. Finally, in vitro biocompatibility was carried out by MTT assay and High Content Analysis for selected dry powder formulations and starting materials. The assays demonstrated the same outcome by confirming the HA biocompatibility and by producing the same rank of toxicity for the surfactants. The general conclusion of the project is that formulation containing HA and stearyl alcohol represents the best performing formulation.