Displaying publications 101 - 120 of 422 in total

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  1. Mirhosseini H, Amid BT
    Chem Cent J, 2013 Jan 04;7(1):1.
    PMID: 23289739 DOI: 10.1186/1752-153X-7-1
    BACKGROUND: A natural carbohydrate biopolymer was extracted from the agricultural biomass waste (durian seed). Subsequently, the crude biopolymer was purified by using the saturated barium hydroxide to minimize the impurities. Finally, the effect of different drying techniques on the flow characteristics and functional properties of the purified biopolymer was investigated. The present study elucidated the main functional characteristics such as flow characteristics, water- and oil-holding capacity, solubility, and foaming capacity.

    RESULTS: In most cases except for oven drying, the bulk density decreased, thus increasing the porosity. This might be attributed to the increase in the inter-particle voids of smaller sized particles with larger contact surface areas per unit volume. The current study revealed that oven-dried gum and freeze-dried gum had the highest and lowest compressibility index, thus indicating the weakest and strongest flowability among all samples. In the present work, the freeze-dried gum showed the lowest angle of repose, bulk, tapped and true density. This indicates the highest porosity degree of freeze dried gum among dried seed gums. It also exhibited the highest solubility, and foaming capacity thus providing the most desirable functional properties and flow characteristics among all drying techniques.

    CONCLUSION: The present study revealed that freeze drying among all drying techniques provided the most desirable functional properties and flow characteristics for durian seed gum.

    Matched MeSH terms: Solubility
  2. Bimakr M, Rahman RA, Taip FS, Adzahan NM, Sarker MZ, Ganjloo A
    Molecules, 2013 Jan 15;18(1):997-1014.
    PMID: 23322066 DOI: 10.3390/molecules18010997
    In the present study, supercritical carbon dioxide (SC-CO(2)) extraction of seed oil from winter melon (Benincasa hispida) was investigated. The effects of process variables namely pressure (150-300 bar), temperature (40-50 °C) and dynamic extraction time (60-120 min) on crude extraction yield (CEY) were studied through response surface methodology (RSM). The SC-CO(2) extraction process was modified using ethanol (99.9%) as co-solvent. Perturbation plot revealed the significant effect of all process variables on the CEY. A central composite design (CCD) was used to optimize the process conditions to achieve maximum CEY. The optimum conditions were 244 bar pressure, 46 °C temperature and 97 min dynamic extraction time. Under these optimal conditions, the CEY was predicted to be 176.30 mg-extract/g-dried sample. The validation experiment results agreed with the predicted value. The antioxidant activity and fatty acid composition of crude oil obtained under optimized conditions were determined and compared with published results using Soxhlet extraction (SE) and ultrasound assisted extraction (UAE). It was found that the antioxidant activity of the extract obtained by SC-CO(2) extraction was strongly higher than those obtained by SE and UAE. Identification of fatty acid composition using gas chromatography (GC) showed that all the extracts were rich in unsaturated fatty acids with the most being linoleic acid. In contrast, the amount of saturated fatty acids extracted by SE was higher than that extracted under optimized SC-CO(2) extraction conditions.
    Matched MeSH terms: Solubility
  3. Tan HW, Misran M
    Int J Pharm, 2013 Jan 30;441(1-2):414-23.
    PMID: 23174410 DOI: 10.1016/j.ijpharm.2012.11.013
    In this study, the preparation of N-pamitoyl chitosan (ChP) anchored oleic acid (OA) liposome was demonstrated. Two different types of water-soluble ChPs with different degrees of acylation (DA) were selected for this study. The presence of ChPs on the surface of OA liposome was confirmed with their micrographs and physicochemical properties. The "peeling off" effect on the surface of the ChP-anchored OA (OAChP) liposomes was observed on the atomic force microscope micrographs and confirmed the presence of the ChPs layer on the liposome surface. The surface tension of the OAChPs liposome solution was found to be higher than that of the OA liposome solution. This result indicated the removal of OA monomer by ChPs from the air-water interface. The increase in the minimum area per headgroup (A(min)) of the OA with the presence of ChPs has further proved the interaction between OA monomer and the hydrophobic moieties of the ChPs. The ChPs anchored onto the OA monolayer increased the curvature of the OAChP liposomes monolayer and reduced the liposome size. The size of the OAChP liposomes was reduced by 30 nm as compared with the unmodified OA liposome. Results revealed that the anchored ChPs can improve the integrity and rigidity of the OA liposome.
    Matched MeSH terms: Solubility
  4. Abedin MZ, Karim AA, Ahmed F, Latiff AA, Gan CY, Che Ghazali F, et al.
    J Sci Food Agric, 2013 Mar 30;93(5):1083-8.
    PMID: 22936269 DOI: 10.1002/jsfa.5854
    Sea cucumber (Stichopus vastus) is considered an underutilized resource, since only its stomach and intestines are eaten raw as salad in a few countries and the remaining parts, especially the integument rich in collagen, is discarded. Hence a valuable by-product having potential nutraceutical and pharmaceutical applications is wasted. In the present investigation, pepsin-solubilized collagen (PSC) from the integument of S. vastus was isolated, purified and characterized.
    Matched MeSH terms: Solubility
  5. Yuzir A, Abdullah N, Chelliapan S, Sallis P
    Bioresour Technol, 2013 Apr;133:158-65.
    PMID: 23422308 DOI: 10.1016/j.biortech.2013.01.086
    The effects of Mecoprop (RS)-MCPP were investigated in an anaerobic membrane bioreactor (AnMBr) fed with synthetic wastewater containing stepwise increases in Mecoprop concentration, 5-200 mg L(-1) over 240 days. Effects were observed in terms of soluble chemical oxygen demand (COD) removal efficiency, volatile fatty acid (VFA) production, and methane yield. Soluble COD removal efficiency was stable at Mecoprop concentrations below 200 (±3) mg L(-1), with an average of 98 (±0.7)% removal. However, at 200 (±3) mg L(-1) Mecoprop, the COD removal efficiency decreased gradually to 94 (±1.5)%. At 5 mg L(-1) Mecoprop, acetic and propionic acid concentrations increased by 60% and 160%, respectively. In contrast, when Mecoprop was increased to 200 (±3) mg L(-1), the formation and degradation of acetate was unaffected by the higher Mecoprop concentration, acetate remaining below 35 mg L(-1). Increases in the Mecoprop specific utilization rate were observed as Mecoprop was increased stepwise between 5 and 200 mg L(-1).
    Matched MeSH terms: Solubility
  6. Koh PT, Chuah JN, Talekar M, Gorajana A, Garg S
    Indian J Pharm Sci, 2013 May;75(3):291-301.
    PMID: 24082345 DOI: 10.4103/0250-474X.117434
    The aim of this study was to enhance the dissolution rate of efavirenz using solid dispersion systems (binary and ternary). A comparison between solvent and fusion method was also investigated. Solid dispersions of efavirenz were prepared using polyethylene glycol 8000, polyvinylpyrrolidone K30 alone and combination of both. Tween 80 was incorporated to obtain a ternary solid dispersion system. Dissolution tests were conducted and evaluated on the basis of cumulative percentage drug release and dissolution efficiency. Physicochemical characterizations of the solid dispersions were carried out using differential scanning calorimetric, powder X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Dissolution was remarkably improved in both systems compared to pure efavirenz (P<0.05). An optimum ratio was identified at a drug:polymer of 1:10. Incorporation of Tween 80 to 1:10 formulations formed using solvent method showed further improvement in the dissolution rate. Physicochemical characterization results suggested that efavirenz existed in the amorphous form in all the solid dispersion systems providing evidence of improvement in dissolution. No statistically significant difference (P>0.05) in dissolution was observed between the two methods. Binary and ternary solid dispersion systems both have showed a significant improvement in the dissolution rate of efavirenz. Formulations with only polyvinylpyrrolidone K30 showed best dissolution profile and 1:10 was identified as an optimum drug-polymer weight ratio.
    Matched MeSH terms: Solubility
  7. Gorajana A, Ying CC, Shuang Y, Fong P, Tan Z, Gupta J, et al.
    Curr Drug Deliv, 2013 Jun;10(3):309-16.
    PMID: 23360246
    Dapivirine, formerly known as TMC 120, is a poorly-water soluble anti-HIV drug, currently being developed as a vaginal microbicide. The clinical use of this drug has been limited due to its poor solubility. The aim of this study was to design solid dispersion systems of Dapivirine to improve its solubility. Solid dispersions were prepared by solvent and fusion methods. Dapivirine release from the solid dispersion system was determined by conducting in-vitro dissolution studies. The physicochemical characteristics of the drug and its formulation were studied using Differential Scanning Calorimetry (DSC), powder X-ray Diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). A significant improvement in drug dissolution rate was observed with the solid dispersion systems. XRD, SEM and DSC results indicated the transformation of pure Dapivirine which exists in crystalline form into an amorphous form in selected solid dispersion formulations. FTIR and HPLC analysis confirmed the absence of drug-excipient interactions. Solid dispersion systems can be used to improve the dissolution rate of Dapivirine. This improvement could be attributed to the reduction or absence of drug crystallinity, existence of drug particles in an amorphous form and improved wettability of the drug.
    Matched MeSH terms: Solubility
  8. Nopianti R, Huda N, Ismail N, Ariffin F, Easa AM
    J Food Sci Technol, 2013 Aug;50(4):739-46.
    PMID: 24425976 DOI: 10.1007/s13197-011-0394-0
    Physicochemical properties of threadfin bream surimi with different levels of polydextrose (3%, 6%, 9% and 12%), raw surimi, raw surimi with addition sodium tripolyphosphate and commercial surimi (sucrose) during 6 months of frozen storage were investigated. The analyses included the measurement of Ca(2+)-ATPase, sulfhydryl contents, protein solubility, sodium dodecyl sulfate polyacrylamide gel electrophoresis, differential scanning calorimetry and scanning electron microscopy. The Ca(2+)-ATPase, sulfhydryl content and protein solubility levels added with 3%, 6%, 9% and 12% polydextrose can be maintained until the 6 months of storage by 47.33%, 41.60% and 51.41%, respectively. Differential scanning calorimetry showed decreases in thermal stabilization of myosin with regard to transition termperature. Analysis by scanning electron microscopy demonstrated that the number of pores formed was increased after storage. This study suggested that surimi stored with the polydextrose as a cryoprotectant was able to maintain physicochemical of surimi better compared to raw surimi with no additives or raw surimi with sodium tripolyphosphate.
    Matched MeSH terms: Solubility
  9. Liew KB, Peh KK, Fung Tan YT
    Pak J Pharm Sci, 2013 Sep;26(5):961-6.
    PMID: 24035953
    An easy, fast and validated RV-HPLC method was invented to quantify donepezil hydrochloride in drug solution and orally disintegrating tablet. The separation was carried out using reversed phase C-18 column (Agilent Eclipse Plus C-18) with UV detection at 268 nm. Method optimization was tested using various composition of organic solvent. The mobile phase comprised of phosphate buffer (0.01M), methanol and acetonitrile (50:30:20, v/v) adjusted to pH 2.7 with phosphoric acid (80%) was found as the optimum mobile phase. The method showed intraday precision and accuracy in the range of 0.24% to -1.83% and -1.83% to 1.99% respectively, while interday precision and accuracy ranged between 1.41% to 1.81% and 0.11% to 1.90% respectively. The standard calibration curve was linear from 0.125 μg/mL to 16 μg/mL, with correlation coefficient of 0.9997±0.00016. The drug solution was stable under room temperature at least for 6 hours. System suitability studies were done. The average plate count was > 2000, tailing factor <1, and capacity factor of 3.30. The retention time was 5.6 min. The HPLC method was used to assay donepezil hydrochloride in tablet and dissolution study of in-house manufactured donepezil orally disintegrating tablet and original Aricept.
    Matched MeSH terms: Solubility
  10. Bose A, Wui WT
    Eur J Drug Metab Pharmacokinet, 2013 Sep;38(3):191-200.
    PMID: 23264125 DOI: 10.1007/s13318-012-0116-7
    The experimental study presents a brief and comprehensive perspective on the methods of developing a Level A in vitro-in vivo correlation (IVIVC) for extended oral dosage forms of water-insoluble drug domperidone. The study also evaluates the validity and predictability of in vitro-in vivo correlation using the convolution technique by one-compartmental first-order kinetic equation. The IVIVC can be substituted as a surrogate for in vivo bioavailability study for the documentation of bioequivalence studies as mandatory from any regulatory authorities. The in vitro drug release studies for different formulations (fast, moderate, slow) were conducted in different dissolution mediums. The f (2) metric (similarity factor) was used to analyze the dissolution data for determination of the most discriminating dissolution method. The in vivo pharmacokinetics parameters of all the formulations were determined by using liquid chromatography mass spectrometry (LC/MS) methods. The absorption rate constant and percentage of absorption of drugs at different time intervals were calculated by using data convolution. In vitro drug release and in vivo absorption correlation were found to be a linear correlation model, which was developed by using percent absorbed drug release versus percent drug dissolved from the three formulations. Internal and external validation was performed to validate the IVIVC. Predicted domperidone concentrations were obtained by convolution technique using first-order one-compartmental fitting equation. Prediction errors estimated for C (max) and AUC (0-infinity) were found to be within the limit.
    Matched MeSH terms: Solubility
  11. Kirby BP, Pabari R, Chen CN, Al Baharna M, Walsh J, Ramtoola Z
    J Pharm Pharmacol, 2013 Oct;65(10):1473-81.
    PMID: 24028614 DOI: 10.1111/jphp.12125
    In this study, we examined the relative cellular uptake of nanoparticles (NPs) formulated using poly(lactic-co-glycolic acid) (PLGA) polymers with increasing degree of pegylation (PLGA-PEG) and their potential to deliver loperamide to the brain of a mouse.
    Matched MeSH terms: Solubility
  12. Oladebeye AO, Oshodi AA, Amoo IA, Karim AA
    Food Chem, 2013 Nov 15;141(2):1416-23.
    PMID: 23790933 DOI: 10.1016/j.foodchem.2013.04.080
    Ozone-oxidised starches were prepared from the native starches isolated from white and red cocoyam, and white and yellow yam cultivars. The native and oxidised starches were evaluated for functional, thermal and molecular properties. The correlations between the amount of reacted ozone and carbonyl and carboxyl contents of the starches were positive, as ozone generation time (OGT) increased. Significant differences were obtained in terms of swelling power, solubility, pasting properties and textural properties of the native starches upon oxidation. The DSC data showed lower transition temperatures and enthalpies for retrograded gels compared to the gelatinized gels of the same starch types. The native starches showed CB-type XRD patterns while the oxidised starches resembled the CA-type pattern. As amylose content increased, amylopectin contents of the starches decreased upon oxidation. Similarly, an increase in Mw values were observed with a corresponding decrease in Mn values upon oxidation.
    Matched MeSH terms: Solubility
  13. Musa SH, Basri M, Masoumi HR, Karjiban RA, Malek EA, Basri H, et al.
    Colloids Surf B Biointerfaces, 2013 Dec 1;112:113-9.
    PMID: 23974000 DOI: 10.1016/j.colsurfb.2013.07.043
    Palm kernel oil esters nanoemulsion-loaded with chloramphenicol was optimized using response surface methodology (RSM), a multivariate statistical technique. Effect of independent variables (oil amount, lecithin amount and glycerol amount) toward response variables (particle size, polydispersity index, zeta potential and osmolality) were studied using central composite design (CCD). RSM analysis showed that the experimental data could be fitted into a second-order polynomial model. Chloramphenicol-loaded nanoemulsion was formulated by using high pressure homogenizer. The optimized chloramphenicol-loaded nanoemulsion response values for particle size, PDI, zeta potential and osmolality were 95.33nm, 0.238, -36.91mV, and 200mOsm/kg, respectively. The actual values of the formulated nanoemulsion were in good agreement with the predicted values obtained from RSM. The results showed that the optimized compositions have the potential to be used as a parenteral emulsion to cross blood-brain barrier (BBB) for meningitis treatment.
    Matched MeSH terms: Solubility
  14. Omar AF, MatJafri MZ
    Sensors (Basel), 2013;13(4):4876-83.
    PMID: 23584118 DOI: 10.3390/s130404876
    This study presents a novel application of near infrared (NIR) spectral linearisation for measuring the soluble solids content (SSC) of carambola fruits. NIR spectra were measured using reflectance and interactance methods. In this study, only the interactance measurement technique successfully generated a reliable measurement result with a coefficient of determination of (R2) = 0.724 and a root mean square error of prediction for (RMSEP) = 0.461° Brix. The results from this technique produced a highly accurate and stable prediction model compared with multiple linear regression techniques.
    Matched MeSH terms: Solubility
  15. Ong YH, Chua AS, Lee BP, Ngoh GC
    Water Sci Technol, 2013;67(2):340-6.
    PMID: 23168633 DOI: 10.2166/wst.2012.552
    To date, little information is known about the operation of the enhanced biological phosphorus removal (EBPR) process in tropical climates. Along with the global concerns on nutrient pollution and the increasing array of local regulatory requirements, the applicability and compliance accountability of the EBPR process for sewage treatment in tropical climates is being evaluated. A sequencing batch reactor (SBR) inoculated with seed sludge from a conventional activated sludge (CAS) process was successfully acclimatized to EBPR conditions at 28 °C after 13 days' operation. Enrichment of Candidatus Accumulibacter phosphatis in the SBR was confirmed through fluorescence in situ hybridization (FISH). The effects of operational pH and influent C:P ratio on EBPR were then investigated. At pH 7 or pH 8, phosphorus removal rates of the EBPR processes were relatively higher when operated at C:P ratio of 3 than C:P ratio of 10, with 0.019-0.020 and 0.011-0.012 g-P/g-MLVSS•day respectively. One-year operation of the 28 °C EBPR process at C:P ratio of 3 and pH 8 demonstrated stable phosphorus removal rate of 0.020 ± 0.003 g-P/g-MLVSS•day, corresponding to effluent with phosphorus concentration <0.5 mg/L. This study provides the first evidence on good EBPR activity at relatively high temperature, indicating its applicability in a tropical climate.
    Matched MeSH terms: Solubility
  16. Lau PL, Allen RW, Styring P
    Beilstein J Org Chem, 2013;9:2886-97.
    PMID: 24367454 DOI: 10.3762/bjoc.9.325
    The palladium metal catalysed Heck reaction of 4-iodoanisole with styrene or methyl acrylate has been studied in a continuous plug flow reactor (PFR) using supercritical carbon dioxide (scCO2) as the solvent, with THF and methanol as modifiers. The catalyst was 2% palladium on silica and the base was diisopropylethylamine due to its solubility in the reaction solvent. No phosphine co-catalysts were used so the work-up procedure was simplified and the green credentials of the reaction were enhanced. The reactions were studied as a function of temperature, pressure and flow rate and in the case of the reaction with styrene compared against a standard, stirred autoclave reaction. Conversion was determined and, in the case of the reaction with styrene, the isomeric product distribution was monitored by GC. In the case of the reaction with methyl acrylate the reactor was scaled from a 1.0 mm to 3.9 mm internal diameter and the conversion and turnover frequency determined. The results show that the Heck reaction can be effectively performed in scCO2 under continuous flow conditions with a palladium metal, phosphine-free catalyst, but care must be taken when selecting the reaction temperature in order to ensure the appropriate isomer distribution is achieved. Higher reaction temperatures were found to enhance formation of the branched terminal alkene isomer as opposed to the linear trans-isomer.
    Matched MeSH terms: Solubility
  17. Zal U’yun Wan Mahmood, Norfaizal Mohamed @ Mohamad, Nik Azlin Nik Ariffin, Abdul Kadir Ishak
    MyJurnal
    An improved laboratory technique for measurement of polonium-210(
    210Po) in environmental
    samples has been developed in Radiochemistry and Environmental Laboratory (RAS), Malaysian
    Nuclear Agency. To further improve this technique, a study with the objectives to determine the
    optimum conditions for
    210Po deposition and; evaluate the accuracy and precision results for
    the determination of 2 1 0 P o in environmental samples was carried-out. Polonium-210 which
    is an alpha emitter obtained in acidic solution through total digestion and dissolution of samples
    has been efficiently plated onto one side of the silver disc in the spontaneous plating process for
    measurement of its alpha activity. The optimum conditions for deposition of 210Po were achieved
    using hydrochloric acid (HCl) media at acidity of 0.5 M with the presence of 1.0 gram hydroxyl
    ammonium chloride and the plating temperature at 90
    oC. The plating was carried out in 80 mL
    HCl solution (0.5 M) for 4 hours. The recorded recoveries obtained using 2 0 9 P o tracers in
    the CRM IAEA-385 and environmental samples were 85% – 98% whereby the efficiency of the
    new technique is a distinct advantage over the existing techniques. Therefore, optimization of
    deposition parameters is a prime importance to achieve accuracy and precision results as well as
    economy and time saving
    Matched MeSH terms: Solubility
  18. Amiza, M.A., Ow, Y.W., Faazaz, A.L.
    MyJurnal
    The physicochemical properties of silver catfish frame hydrolysate powder at three different degree of hydrolysis, DH43%, DH 55% and DH 68% were studied. The hydrolysates powder were obtained by hydrolysis using Alcalase®, centrifugation and spray drying of the supernatant. The study found that preparation of these hydrolysates affected the protein, ash and fat content as well as amino acid composition. As for essential amino acids, their values were generally considered as adequate as compared to the suggested essential amino acids profile of FAO/WHO. The results showed that SFHs were rich in lysine and glutamate. Hydrolysate at DH 68% exhibited better peptide solubility and water holding capacity. As degree of hydrolysis increased, emulsifying capacity and foaming capacity of the hydrolysate decreased. It was also found that the lightness in hydrolysate powder decreased with increase in degree of hydrolysis. This study shows that silver catfish frame hydrolysate has good solubility, good foaming properties and light colour profile, thus having high potential as food ingredient.
    Matched MeSH terms: Solubility
  19. Venkateskumar Krishnamoorthy, Verma Priya Ranjan Prasad, Suchandrasen Sen
    MyJurnal
    exhibits extensive first pass metabolism with poor oral bioavailability (27%–50%) limiting its therapeutic efficiency. The present study involved an attempt to enhance its aqueous solubility by formulating as solid dispersions (SDs) using sodium starch glycollate (SSG) as a carrier. The dispersions were formulated by dispersion method and evaluated by phase solubility, drug content, in vitro release and mathematical modelling. Solid state characterisation of samples was carried out by X-ray diffraction (XRD), differential scanning calorimetric (DSC), Fourier transform infrared spectrophotometry (FTIR), near infrared (NIR), Raman analysis and wettability studies. The phase solubility and thermodynamic parameters indicated the spontaneity and solubilisation effect of carrier. The release rate from the dispersions was higher than pure drug and found to increase with an increase in carrier content. The optimised dispersions were selected based on release studies, profiles and dissolution parameters. XRD, DSC, FTIR, NIR and Raman analysis proved the crystallinity reduction, changes in crystal quality and compatibility between drug and carriers. Wettability studies proved the increased wettability in selected dispersions. Based on the findings, possible mechanisms that would have contributed to dissolution enhancement of CLZ were suggested. Such findings could be extrapolated to enhance the aqueous solubility of other poorly water-soluble drugs.
    Matched MeSH terms: Solubility
  20. Normah Ismail, Najihah Shukor, Zainal Samicho
    MyJurnal
    Silver catfish (Pangasius sutchi) skin gelatin was extracted to determine the effects of extraction time on the functional properties of the gelatin in terms of solubility, protein solubility as a function of pH and sodium chloride concentration, emulsifying capacity and stability, water holding capacity, fat binding capacities and foaming properties. Silver catfish skins were washed in sodium chloride (NaCl) solution prior to pre-treatment in sodium hydroxide (NaOH) and acetic acid solution. Gelatin was extracted at 50ºC for 6, 8, 10 and 12 hours extraction time followed by freeze drying. The extraction of silver catfish skin gelatin at 50 ºC for 12 hours was more effective than extraction at 6, 8 and 10 hours where the gelatin was characterized by higher emulsifying capacity (52.63%), emulsifying stability (47.83%), water holding capacity (31.78 mL/g), fat binding capacities (54.76%), foaming capacity (41.47 mL) and foaming stability (56.42%) than gelatins extracted at other extraction time. The longer the extraction time, the better the functional properties of the gelatin. Based on its good functional properties, silver catfish skin gelatin may be useful in various food applications such as soups, sauces and gravies.
    Matched MeSH terms: Solubility
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