14 research outputs found

    Selective Polarity-guided Extraction and Purification of Acetogenins in Annona muricata L. Leaves

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    Herein is described the selective polar-guided extraction and column chromatography separation of annonaceous acetogenins from the leaves of Annona muricata L., commonly known as soursop. The objective of this study is to obtain an acetogenin-rich fraction, containing mainly annonacin, known to be present in the highest amount in soursop leaves. Solvents with various polarities (ethyl acetate, hexane, chloroform, ethanol, water) and their mixtures were used in the extraction, fractionation, and isolation steps. The liquid chromatography-mass spectrometry analysis of the isolate sample showed that annonacin, having a molecular mass of 597.23, is the dominant acetogenin present. The amount of acetogenin isolated from the soursop leaf samples was 242 mg/g, based on the total lactone determination using the Kedde reagent. The cytotoxicity activity of the isolate sample was determined using the brine shrimp test. This study shows that there is a positive correlation between lactone content due to acetogenins and the level of cytotoxicity in the fractions obtained. The low LC50 value of 1 ppm showed a significant cytotoxicity of the ethyl acetate fraction obtained, higher than cytotoxicity of cancer drug cyclophosphamide. High lactone content and a high cytotoxicity of the ethyl acetate fraction indicate the potential of A. muricata leaves as the source of bioactive compounds for anti-cancer treatment

    Mathematical Model Controlled Potassium Chloride Release Systems from Chitosan Microspheres

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    Chitosan can be prepared in the form of microspheres that serve as a depot for bioactive compounds released in a controlled way to diseased organs. In this study, a mathematical model of potassium chloride release from chitosan microspheres was developed. The model was validated using experimental data. The potassium chloride-loading percentages of 10.01%, 20.84%, and 20.57% were prepared using a cross-linking method. The potassium chloride loading was kept constant at about 20% when the potassium chloride mass in the preparation stage was above 5.024 mg/mL. Experiments and a model calculation of potassium chloride release from the microspheres with a loading of 10.01% and 20.57% were performed. In general, the model reproduces the experimental data. The experiments and the calculation show that during the same period, microspheres containing more potassium chloride release a higher percentage of potassium chloride than do microspheres containing less potassium chloride

    Study of microfine cement use on squeeze cementing operations in plug and abandonment work

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    The purpose of this study is to develop guideline and decision tree for selecting proper material of squeeze cementing operation as part of permanent well abandonment project in PT XYZ. The existing guideline in oil and gas industry does not cover the detail of cement type selection prior to do squeeze cementing job and this may cause failure in the operation and give the high cost impact due to remedial job. It is expected that the result of decision tree and guideline in this study can be used as a reference for plug and abandonment project in. The method used in this research is by calculating the value of the injectivity factor obtained from field study as a key factor in determining the type of cement for squeeze cementing operation. If the injector factor value is less than 2000 ( 2000), the reservoir is considered as tight formation and difficult to penetrate, so the use of microfine cement is expected to isolate the reservoir formation zone

    Study of microfine cement use on squeeze cementing operations in plug and abandonment work

    No full text
    The purpose of this study is to develop guideline and decision tree for selecting proper material of squeeze cementing operation as part of permanent well abandonment project in PT XYZ. The existing guideline in oil and gas industry does not cover the detail of cement type selection prior to do squeeze cementing job and this may cause failure in the operation and give the high cost impact due to remedial job. It is expected that the result of decision tree and guideline in this study can be used as a reference for plug and abandonment project in. The method used in this research is by calculating the value of the injectivity factor obtained from field study as a key factor in determining the type of cement for squeeze cementing operation. If the injector factor value is less than 2000 ( 2000), the reservoir is considered as tight formation and difficult to penetrate, so the use of microfine cement is expected to isolate the reservoir formation zone

    The Effect of Eugenol and Chitosan Concentration on the Encapsulation of Eugenol Using Whey Protein–Maltodextrin Conjugates

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    Eugenol has many functional properties for food and pharmaceutical purposes, especially as an antimicrobial agent. However, its use is constrained by its volatility and shelf life because it is easily degraded due to temperature, oxidation, and light. Research on encapsulation technology using biopolymers is still required to obtain the appropriate formulation in a eugenol delivery system. The aims of this research were to develop a new formulation of protein and polysaccharides in eugenol encapsulation and to determine the effect of eugenol and chitosan concentration on the characteristics of the emulsions and spray-dried powder produced. In this study, eugenol was encapsulated in whey protein–maltodextrin conjugates and chitosan through the double layer encapsulation method. The emulsions which were prepared with 2.0% eugenol were relatively more stable than those of 1.0% eugenol based on the polydispersity index and zeta potential values. Spray-dried powder which was prepared using an emulsion of 2.0% w/w eugenol and 0.33% w/w chitosan had the highest eugenol loading. The presence of chitosan resulted in more stable emulsions based on their zeta potential values, improved thermal stability of eugenol, increased eugenol loading to become twice as much as the loading obtained without chitosan, and modified release profile of eugenol from the spray-dried powders

    Optimization of Chitosan–Alginate Microparticles for Delivery of Mangostins to the Colon Area Using Box–Behnken Experimental Design

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    Chitosan-alginate microparticles loaded with hydrophobic mangostins present in the mangosteen rind extract have been formulated and optimized for colon-targeted bioactive drug delivery systems. The chitosan–mangostin microparticles were prepared using the ionotropic gelation method with sodium tripolyphosphate as the cross-linking agent of chitosan. The chitosan–mangostin microparticles were then encapsulated in alginate with calcium chloride as the linking agent. The mangostin release profile was optimized using the Box–Behnken design for response surface methodology with three independent variables: (A) chitosan–mangostin microparticle size, (B) alginate:chitosan mass ratio, and (C) concentration of calcium chloride. The following representative equation was obtained: percent cumulative release of mangostins (10 h) = 59.51 − 5.16A + 20.00B − 1.27C − 1.70AB − 5.43AC − 5.04BC + 0.0579A2 + 10.25B2 + 1.10C2. Cumulative release of 97% was obtained under the following optimum condition for microparticle preparation: chitosan–mangosteen particle size < 100 µm, alginate:chitosan mass ratio of 0.5, and calcium chloride concentration of 4% w/v. The alginate to chitosan mass ratio is the statistically significant variable in the optimization of sequential release profile of mangostins in simulated gastrointestinal fluids. Furthermore, a sufficient amount of alginate is necessary to modify the chitosan microparticles and to achieve a complete release of mangostins. The results of this work indicate that the complete release of mangostins to the colon area can be achieved using the chitosan–alginate microparticles as the bioactive delivery system

    Formulation and characterization of nanoemulgel mangosteen extract in virgin coconut oil for topical formulation

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    A hydrogel of nanoemulsion system containing mangosteen extract of mangosteen rind was developed and characterized for the purpose of topical formulation. Mangostins, the bioactive in the extract, has been known to have biological activities such as antifungal, antibacterial, antioxidant, antiviral and antitumoral. Due to the hydrophobic nature of mangostins, they can not to be directly formulated into a gel. Oil-in-water nanoemulsions were formulated of virgin coconut oil (VCO) as the oil phase and mixed surfactant consisting of Tween 80 and Span 80, using the high-speed homogenization method. Nanoemulgel formed by mixing the nanoemulsion with aqueous solution of xanthan gum, and added phenoxyethanol as a preservative, was a homogeneous milky white gel. The stability test through accelerated centrifugation and freeze-thaw cycle showed that the nanoemulgel would be stable for at least one year. The nanoemulgel penetrated the skin layer up to 12 ÎĽg/cm2 or more than 95% of its total mangostin content, better than the skin penetration result of the nanoemulsion formulation. The present study revealed that VCO-mangostins nanoemulgel formulation is a prospective topical formulation

    Deacidification of Palm Oil Using Betaine Monohydrate-Carboxylic Acid Deep Eutectic Solvents: Combined Extraction and Simple Solvent Recovery

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    Steam stripping is commonly used to remove free fatty acids from crude palm oil. An alternative deacidification method, solvent extraction performed at a much lower temperature, would preserve the natural antioxidants in the refined palm oil. In this work, palmitic acid was extracted using betaine monohydrate-propionic acid and betaine monohydrate-acetic acid deep eutectic solvents (DESs). The effect of temperature (40 °C to 80 °C), mass ratio of palm oil to solvent (2:1 to 1:2), and palmitic acid content in the palm oil feed (2% to 8% mass) on the distribution coefficient values of palmitic acid (0.44–0.93) was investigated. For the first time, a facile recovery of DESs could be accomplished by a cooling process where up to 98% of the palmitic acid separates as solid. A solvent extraction process for palm oil deacidification, employing a DES with a distribution coefficient value much higher than unity, will provide advantages over the steam stripping process

    Cyclic Voltammetry and Oxidation Rate Studies of Ferrous Gluconate Complex Solutions for Preparation of Chitosan-Tripolyphosphate Microparticles

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    A proper understanding of the properties of iron could increase the effectiveness of programmes for alleviating iron deficiency. Recently, encapsulation has been considered an appropriate method for protecting iron from injurious reactions. However, several events may occur during encapsulation processes, including changes in the iron’s oxidation state. Oxidation of ferrous iron is not desirable since the intestines can only absorb iron in the ferrous form. In this study, a cyclic voltammetry method was applied to investigate the likelihood of ferrous gluconate oxidation for the preparation of chitosan-tripolyphosphate microparticles. Then, the electrochemical properties of ferrous gluconate were confirmed experimentally. The oxidation rate of ferrous gluconate is also discussed in this paper. All the experimental solutions were formulated in detail to produce conditions similar to those of microparticle production. Cyclic voltammetry analysis was conducted using a configuration of three electrodes connected to an electrochemical analyser. Graphite, platinum wire, and Ag/AgCl were employed as the auxiliary, working, and reference electrodes, respectively. The cyclic voltammetry results show that the observed potential for each anodic peak shifted negatively in the presence of chitosan and sodium tripolyphosphate. Moreover, the rate of ferrous oxidation tended to increase during 75 min of experiments due to the presence of chitosan and sodium tripolyphosphate. These behaviours indicate the transformation of ferrous iron to ferric iron during iron microparticle preparation. Furthermore, these findings suggest that spray drying is a preferable method to minimise the oxidation reaction
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