Displaying publications 81 - 100 of 177 in total

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  1. Salehabadi A, Bakar MA, Bakar NHHA
    Materials (Basel), 2014 Jun 13;7(6):4508-4523.
    PMID: 28788689 DOI: 10.3390/ma7064508
    Multi-component nanohybrids comprising of organo-modified montmorillonite (MMT) and immiscible biopolymer blends of poly(3-hydroxybutyrate) (PHB) and epoxidized natural rubber (ENR-50) were prepared by solvent casting technique. The one and three dimensional morphology of PHB/ENR-50/MMT systems were studied using Polarizing Optical Microscopy (POM) and Scanning Electron Microscopy (SEM). Differential scanning calorimetry (DSC) technique was used to evaluate the thermal properties of the nanohybrids. The melting temperature (Tm) and enthalpy of melting (ΔHm) of PHB decrease with respect to the increase in ENR-50 as well as MMT content. The non-isothermal decomposition of the nanohybrids was studied using thermogravimetric (TG-DTG) analysis. FTIR-ATR spectra supported ring opening of the epoxide group via reaction with carboxyl group of PHB and amines of organic modifier. The reaction mechanism towards the formation of the nanohybrids is proposed.
    Matched MeSH terms: Calorimetry, Differential Scanning
  2. Azir M, Abbasiliasi S, Tengku Ibrahim TA, Manaf YNA, Sazili AQ, Mustafa S
    Foods, 2017 Nov 09;6(11).
    PMID: 29120362 DOI: 10.3390/foods6110098
    The present study investigates the detection of lard in cocoa butter through changes in fatty acids composition, triacylglycerols profile, and thermal characteristics. Cocoa butter was mixed with 1% to 30% (v/v) of lard and analyzed using a gas chromatography flame ionization detector, high performance liquid chromatography, and differential scanning calorimetry. The results revealed that the mixing of lard in cocoa butter showed an increased amount of oleic acid in the cocoa butter while there was a decrease in the amount of palmitic acid and stearic acids. The amount of POS, SOS, and POP also decreased with the addition of lard. A heating thermogram from the DSC analysis showed that as the concentration of lard increased from 3% to 30%, two minor peaks at -26 °C and 34.5 °C started to appear and a minor peak at 34.5 °C gradually overlapped with the neighbouring major peak. A cooling thermogram of the above adulterated cocoa butter showed a minor peak shift to a lower temperature of -36 °C to -41.5 °C. Values from this study could be used as a basis for the identification of lard from other fats in the food authentication process.
    Matched MeSH terms: Calorimetry, Differential Scanning
  3. Edueng K, Mahlin D, Gråsjö J, Nylander O, Thakrani M, Bergström CAS
    Molecules, 2019 Jul 27;24(15).
    PMID: 31357587 DOI: 10.3390/molecules24152731
    This study explores the effect of physical aging and/or crystallization on the supersaturation potential and crystallization kinetics of amorphous active pharmaceutical ingredients (APIs). Spray-dried, fully amorphous indapamide, metolazone, glibenclamide, hydrocortisone, hydrochlorothiazide, ketoconazole, and sulfathiazole were used as model APIs. The parameters used to assess the supersaturation potential and crystallization kinetics were the maximum supersaturation concentration (Cmax,app), the area under the curve (AUC), and the crystallization rate constant (k). These were compared for freshly spray-dried and aged/crystallized samples. Aged samples were stored at 75% relative humidity for 168 days (6 months) or until they were completely crystallized, whichever came first. The solid-state changes were monitored with differential scanning calorimetry, Raman spectroscopy, and powder X-ray diffraction. Supersaturation potential and crystallization kinetics were investigated using a tenfold supersaturation ratio compared to the thermodynamic solubility using the µDISS Profiler. The physically aged indapamide and metolazone and the minimally crystallized glibenclamide and hydrocortisone did not show significant differences in their Cmax,app and AUC when compared to the freshly spray-dried samples. Ketoconazole, with a crystalline content of 23%, reduced its Cmax,app and AUC by 50%, with Cmax,app being the same as the crystalline solubility. The AUC of aged metolazone, one of the two compounds that remained completely amorphous after storage, significantly improved as the crystallization kinetics significantly decreased. Glibenclamide improved the most in its supersaturation potential from amorphization. The study also revealed that, besides solid-state crystallization during storage, crystallization during dissolution and its corresponding pathway may significantly compromise the supersaturation potential of fully amorphous APIs.
    Matched MeSH terms: Calorimetry, Differential Scanning
  4. Teoh XY, Bt Mahyuddin FN, Ahmad W, Chan SY
    Pharm Dev Technol, 2020 Feb;25(2):245-251.
    PMID: 31690150 DOI: 10.1080/10837450.2019.1689401
    Poor solubility and bioavailability of drugs are often affected by its microscopic structural properties. Nitrofurantoin (NF), a Biopharmaceutics Classification System class II item, has a low water solubility with low plasma concentrations. To improve its therapeutic efficacy, formulation strategy of solid dispersion (SD) and co-crystallization are compared herein. The co-crystal is prepared with citric acid in 1:1 stoichiometric ratio while SD consists of 30% w/w nitrofurantoin and 70% w/w hydroxypropyl methylcellulose (HPMC) as the carrier system. As a control, the physical mixture of NF and HPMC was prepared. All the preparations were characterized with differential scanning calorimetry (DSC), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), microscopy analysis, solubility, and dissolution studies. The formation of co-crystal, solvent evaporated, and spray-dried SD are confirmed by the ATR-FTIR where peaks shifting of several functional groups indicate the formation of the hydrogen bond. Dissolution studies showed a greater initial dissolution rate in co-crystal than SD despite the possible presence of amorphous content in the SD system. Overall, co-crystal is concluded to be a better approach than SD for an effective dissolution.
    Matched MeSH terms: Calorimetry, Differential Scanning/methods
  5. Huu Phong T, Van Thuoc D, Sudesh K
    Int J Biol Macromol, 2016 Mar;84:361-6.
    PMID: 26708435 DOI: 10.1016/j.ijbiomac.2015.12.037
    A halophilic bacterium isolated from mangrove soil sample in Northern Vietnam, Yangia sp. ND199 was found capable of producing homopolymer poly(3-hydroxybutyrate) [P(3HB)], copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)], and copolymer poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] from different carbon sources. The presence of 3HB, 3HV, and 4HB monomers were confirmed by gas chromatography and nuclear magnetic resonance analysis. Only P(3HB) was produced using carbon sources such as fructose or by a combination of fructose with 1,5-pentanediol, 1,6-hexanediol, sodium hexanoate, or sodium octanoate. The biosynthesis of P(3HB-co-3HV) was achieved by adding cosubstrates such as sodium valerate and sodium heptanoate. When 1,4-butanediol, γ-butyrolactone or sodium 4-hydroxybutyrate was added to the culture medium, P(3HB-co-4HB) containing 4.0-7.1mol% 4HB fraction was accumulated. The molecular weights and thermal properties of polyesters were determined by gel permeation chromatography and differential scanning calorimeter, respectively. The results showed that Yangia sp. ND199 is able to produce polyester with high weight average molecular weight ranging from 1.3×10(6) to 2.2×10(6) Dalton and number average molecular weight ranging from 4.2×10(5) to 6.9×10(5) Dalton. The molecular weights, glass transition temperature as well as melting temperature of homopolymer P(3HB) are higher than those of copolymer P(3HB-co-3HV) or P(3HB-co-4HB).
    Matched MeSH terms: Calorimetry, Differential Scanning
  6. Arjmandi R, Hassan A, Haafiz MK, Zakaria Z, Islam MS
    Int J Biol Macromol, 2016 Jan;82:998-1010.
    PMID: 26592699 DOI: 10.1016/j.ijbiomac.2015.11.028
    Polylactic acid (PLA) nanocomposites reinforced with hybrid montmorillonite/cellulose nanowhiskers [MMT/CNW(SO4)] were prepared by solution casting. The CNW(SO4) nanofiller was first isolated from microcrystalline cellulose using acid hydrolysis treatment. PLA/MMT/CNW(SO4) hybrid nanocomposites were prepared by the addition of various amounts of CNW(SO4) [1-9 parts per hundred parts of polymer (phr)] into PLA/MMT nanocomposite at 5 phr MMT content, based on highest tensile strength values as reported previously. The biodegradability, thermal, tensile, morphological, water absorption and transparency properties of PLA/MMT/CNW(SO4) hybrid nanocomposites were investigated. The Biodegradability, thermal stability and crystallinity of hybrid nanocomposites increased compared to PLA/MMT nanocomposite and neat PLA. The highest tensile strength of hybrid nanocomposites was obtained by incorporating 1 phr CNW(SO4) [∼ 36 MPa]. Interestingly, the ductility of hybrid nanocomposites increased significantly by 87% at this formulation. The Young's modulus increased linearly with increasing CNW(SO4) content. This is due to the relatively good dispersion of nanofillers in the hybrid nanocomposites, as revealed by transmission electron microscopy. Fourier transform infrared spectroscopy indicated the formation of some polar interactions. In addition, water resistance of the hybrid nanocomposites improved and the visual transparency of neat PLA film did not affect by addition of CNW(SO4).
    Matched MeSH terms: Calorimetry, Differential Scanning
  7. Amekyeh H, Billa N, Yuen KH, Chin SL
    AAPS PharmSciTech, 2015 Aug;16(4):871-7.
    PMID: 25588365 DOI: 10.1208/s12249-014-0279-4
    The gastrointestinal (GI) transit behavior of and absorption from an amphotericin B (AmB) solid lipid nanoformulation (SLN) in rats was investigated. We aimed to estimate the gastric emptying time (GET) and cecal arrival time (CAT) of AmB SLN in rats as animal models. From these two parameters, an insight on the absorption window of AmB was ascertained. Three types of SLNs, AmB, paracetamol (PAR), and sulfasalazine (SSZ), were similarly formulated using beeswax/theobroma oil composite as the lipid matrix and characterized with regard to size, viscosity, density, migration propensity within agarose gel, in vitro drug release, morphology, gastrointestinal transit, and in vivo absorption. The GET and CAT were estimated indirectly using marker drugs: PAR and sulfapyridine (SP). All three types of SLNs exhibited identical properties with regard to z-average, viscosity, relative density, and propensity to migrate. PAR was absorbed rapidly from the small intestine following emptying of the SLNs giving the T50E (time for 50% absorption of PAR) to be 1.6 h. SP was absorbed after release and microbial degradation of SSZ from SLN in the colon with a lag time of 2 h post-administration, serving as the estimated cecal arrival time of the SLNs. AmB within SLN was favorably absorbed from the small intestine, albeit slowly.
    Matched MeSH terms: Calorimetry, Differential Scanning
  8. Tan IS, Lee KT
    Bioresour Technol, 2015 May;184:386-94.
    PMID: 25465785 DOI: 10.1016/j.biortech.2014.10.146
    A novel concept for the synthesis of a stable polymer hybrid matrix bead was developed in this study. The beads were further applied for enzyme immobilization to produce stable and active biocatalysts with low enzyme leakage, and high immobilization efficiency, enzyme activity, and recyclability. The immobilization conditions, including PEI concentration, activation time and pH of the PEI solution were investigated and optimized. All formulated beads were characterized for its functionalized groups, composition, surface morphology and thermal stability. Compared with the free β-glucosidase, the immobilized β-glucosidase on the hybrid matrix bead was able to tolerate broader range of pH values and higher reaction temperature up to 60 °C. The immobilized β-glucosidase was then used to hydrolyse pretreated macroalgae cellulosic residue (MCR) for the production of reducing sugar and a hydrolysis yield of 73.4% was obtained. After repeated twelve runs, immobilized β-glucosidase retained about 75% of its initial activity.
    Matched MeSH terms: Calorimetry, Differential Scanning
  9. Razavi M, Nyamathulla S, Karimian H, Moghadamtousi SZ, Noordin MI
    Molecules, 2014;19(9):13909-31.
    PMID: 25197930 DOI: 10.3390/molecules190913909
    The gastroretentive dosage form of famotidine was modified using tamarind seed powders to prolong the gastric retention time. Tamarind seeds were used in two different forms having different swelling and gelling properties: with husk (TSP) or without husk (TKP). TKP (TKP1 to TKP 6) and TSP (TSP1 to TSP 6) series were prepared using tamarind powder:xanthan in the ratios of 5:0, 4:1, 3:2, 2:3, 1:4, 0:5, respectively. The matrix tablets were prepared by the wet granulation method and evaluated for pharmacopoeial requirements. TKP2 was the optimum formulation as it had a short floating lag time (FLT<30 s) and more than 98.5% drug release in 12 h. The dissolution data were fitted to popular mathematical models to assess the mechanism of drug release, and the optimum formulation showed a predominant first order release and diffusion mechanism. It was concluded that the TKP2 prepared using tamarind kernel powder:xanthan (4:1) was the optimum formulation with shortest floating lag time and more than 90% release in the determined period of time.
    Matched MeSH terms: Calorimetry, Differential Scanning
  10. Tan SW, Billa N
    AAPS PharmSciTech, 2014 Apr;15(2):287-95.
    PMID: 24318197 DOI: 10.1208/s12249-013-0056-9
    We aimed to investigate the effects that natural lipids, theobroma oil (TO) and beeswax (BW), might have on the physical properties of formulated nanoparticles and also the degree of expulsion of encapsulated amphotericin B (AmB) from the nanoparticles during storage. Lecithin and sodium cholate were used as emulsifiers whilst oleic acid (OA) was used to study the influence of the state of orderliness/disorderliness within the matrices of the nanoparticles on the degree of AmB expulsion during storage. BW was found to effect larger z-average diameter compared with TO. Lecithin was found to augment the stability of the nanoparticles imparted by BW and TO during storage. An encapsulation efficiency (%EE) of 59% was recorded when TO was the sole lipid as against 42% from BW. In combination however, the %EE dropped to 39%. When used as sole lipid, TO or BW formed nanoparticles with comparatively higher enthalpies, 21.1 and 23.3 J/g respectively, which subsequently caused significantly higher degree of AmB expulsion, 81 and 83% respectively, whilst only 11.8% was expelled from a binary TO/BW mixture. A tertiary TO/BW/OA mixture registered the lowest enthalpy at 8.07 J/g and expelled 12.6% of AmB but encapsulated only 22% of AmB. In conclusion, nanoparticles made from equal concentrations of TO and BW produced the most desirable properties and worthy of further investigations.
    Matched MeSH terms: Calorimetry, Differential Scanning
  11. Silverajah VS, Ibrahim NA, Zainuddin N, Yunus WM, Hassan HA
    Molecules, 2012 Oct 08;17(10):11729-47.
    PMID: 23044711 DOI: 10.3390/molecules171011729
    Poly(lactic acid) (PLA) is known to be a useful material in substituting the conventional petroleum-based polymer used in packaging, due to its biodegradability and high mechanical strength. Despite the excellent properties of PLA, low flexibility has limited the application of this material. Thus, epoxidized palm olein (EPO) was incorporated into PLA at different loadings (1, 2, 3, 4 and 5 wt%) through the melt blending technique and the product was characterized. The addition of EPO resulted in a decrease in glass transition temperature and an increase of elongation-at-break, which indicates an increase in the PLA chain mobility. PLA/EPO blends also exhibited higher thermal stability than neat PLA. Further, the PLA/1 wt% EPO blend showed enhancement in the tensile, flexural and impact properties. This is due to improved interaction in the blend producing good compatible morphologies, which can be revealed by Scanning Electron Microscopy (SEM) analysis. Therefore, PLA can be efficiently plasticized by EPO and the feasibility of its use as flexible film for food packaging should be considered.
    Matched MeSH terms: Calorimetry, Differential Scanning
  12. Giita Silverajah VS, Ibrahim NA, Yunus WM, Hassan HA, Woei CB
    Int J Mol Sci, 2012;13(5):5878-98.
    PMID: 22754338 DOI: 10.3390/ijms13055878
    In this work, poly(lactic acid) (PLA) a fully biodegradable thermoplastic polymer matrix was melt blended with three different epoxidized palm oil (EPO). The aim of this research was to enhance the flexibility, mechanical and thermal properties of PLA. The blends were prepared at various EPO contents of 1, 2, 3, 4 and 5 wt% and characterized. The SEM analysis evidenced successful modification on the neat PLA brittle morphology. Tensile tests indicate that the addition of 1 wt% EPO is sufficient to improve the strength and flexibility compared to neat PLA. Additionally, the flexural and impact properties were also enhanced. Further, DSC analysis showed that the addition of EPO results in a decrease in T(g), which implies an increase in the PLA chain mobility. In the presence of 1 wt% EPO, TGA results revealed significant increase in the thermal stability by 27%. Among the three EPOs used, EPO(3) showed the best mechanical and thermal properties compared to the other EPO's, with an optimum loading of 1 wt%. Conclusively, EPO showed a promising outcome to overcome the brittleness and improve the overall properties of neat PLA, thus can be considered as a potential plasticizer.
    Matched MeSH terms: Calorimetry, Differential Scanning
  13. Aisha AF, Ismail Z, Abu-Salah KM, Majid AM
    J Pharm Sci, 2012 Feb;101(2):815-25.
    PMID: 22081501 DOI: 10.1002/jps.22806
    α-Mangostin is an oxygenated heterocyclic xanthone with remarkable pharmacological properties, but poor aqueous solubility and low oral bioavailability hinder its therapeutic application. This study sought to improve the compound's solubility and study the mechanism underlying solubility enhancement. Solid dispersions of α-mangostin were prepared in polyvinylpyrrolidone (PVP) by solvent evaporation method and showed substantial enhancement of α-mangostin's solubility from 0.2 ± 0.2 μg/mL to 2743 ± 11 μg/mL. Fourier transform infrared spectroscopy and differential scanning calorimetry indicated interaction between α-mangostin and PVP. Transmission electron microscopy and dynamic light scattering showed self-assembly of round anionic nanomicelles with particle size in the range 99-127 nm. Powder X-ray diffraction indicated conversion of α-mangostin from crystalline into amorphous state, and scanning electron microscopy showed the presence of highly porous powder. Studies using the fluorescent probe pyrene showed that the critical micellar concentration is about 77.4 ± 4 μg/mL. Cellular uptake of nanomicelles was found to be mediated via endocytosis and indicated intracellular delivery of α-mangostin associated with potent cytotoxicity (median inhibitory concentration of 8.9 ± 0.2 μg/mL). Improved solubility, self-assembly of nanomicelles, and intracellular delivery through endocytosis may enhance the pharmacological properties of α-mangostin, particularly antitumor efficacy.
    Matched MeSH terms: Calorimetry, Differential Scanning
  14. Mohammed IA, Hamidi RM
    Molecules, 2012 Jan 10;17(1):645-56.
    PMID: 22233565 DOI: 10.3390/molecules17010645
    The phenolic Schiff bases I-VI were synthesized by condensation reactions between various diamines, namely o-dianisidine, o-tolidine and ethylenediamine with vanillin or p-hydroxybenzaldehyde and subsequent reactions between these phenolic Schiff bases and epichlorohydrin to produce new diglycidyl ethers Ia-VIa. The structures of these compounds were confirmed by CHN, FT-IR, (1)H-NMR, and (13)C-NMR spectroscopy. Their thermotropic liquid crystalline behavior was studied using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). All the diglycidyl ethers prepared exhibit nematic mesophases, except for Va and VIa, which did not show any transition mesophases, but simply flow to liquids.
    Matched MeSH terms: Calorimetry, Differential Scanning
  15. Saadi S, Ariffin AA, Ghazali HM, Miskandar MS, Abdulkarim SM, Boo HC
    J Food Sci, 2011 Jan-Feb;76(1):C21-30.
    PMID: 21535649 DOI: 10.1111/j.1750-3841.2010.01922.x
    The ability of palm oil (PO) to crystallize as beta prime polymorph has made it an attractive option for the production of margarine fat (MF). Palm stearin (PS) expresses similar crystallization behavior and is considered one of the best substitutes of hydrogenated oils due to its capability to impart the required level of plasticity and body to the finished product. Normally, PS is blended with PO to reduce the melting point at body temperature (37 °C). Lipid phase, formulated by PO and PS in different ratios were subjected to an emulsification process and the following analyses were done: triacylglycerols, solid fat content (SFC), and thermal behavior. In addition, the microstructure properties, including size and number of crystals, were determined for experimental MFs (EMFs) and commercial MFs (CMFs). Results showed that blending and emulsification at PS levels over 40 wt% significantly changed the physicochemical and microstructure properties of EMF as compared to CMF, resulting in a desirable dipalmitoyl-oleoyl-glycerol content of less than 36.1%. SFC at 37 °C, crystal size, crystal number, crystallization, and melting enthalpies (ΔH) were 15%, 5.37 μm, 1425 crystal/μm(2), 17.25 J/g, and 57.69J/g, respectively. All data reported indicate that the formation of granular crystals in MFs was dominated by high-melting triacylglycerol namely dipalmitoyl-oleoyl-glycerol, while the small dose of monoacylglycerol that is used as emulsifier slowed crystallization rate. Practical Application: Most of the past studies were focused on thermal behavior of edible oils and some blends of oils and fats. The crystallization of oils and fats are well documented but there is scarce information concerning some mechanism related to crystallization and emulsification. Therefore, this study will help to gather information on the behavior of emulsifier on crystallization regime; also the dominating TAG responsible for primary granular crystal formations, as well as to determine the best level of stearin to impart the required microstructure properties and body to the finished products.
    Matched MeSH terms: Calorimetry, Differential Scanning
  16. Cheong LZ, Tan CP, Long K, Affandi Yusoff MS, Lai OM
    J Sci Food Agric, 2010 Oct;90(13):2310-7.
    PMID: 20661900 DOI: 10.1002/jsfa.4088
    Diacylglycerol (DAG), which has health-enhancing properties, is sometimes added to bakery shortening to produce baked products with enhanced physical functionality. Nevertheless, the quantity present is often too little to exert any positive healthful effects. This research aimed to produce bakery shortenings containing significant amounts of palm diacyglycerol (PDG). Physicochemical, textural and viscoelastic properties of the PDG bakery shortenings during 3 months storage were evaluated and compared with those of commercial bakery shortening (CS).
    Matched MeSH terms: Calorimetry, Differential Scanning
  17. Lahijani P, Zainal ZA
    Bioresour Technol, 2011 Jan;102(2):2068-76.
    PMID: 20980143 DOI: 10.1016/j.biortech.2010.09.101
    Gasification of palm empty fruit bunch (EFB) was investigated in a pilot-scale air-blown fluidized bed. The effect of bed temperature (650-1050 °C) on gasification performance was studied. To explore the potential of EFB, the gasification results were compared to that of sawdust. Results showed that maximum heating values (HHV) of 5.37 and 5.88 (MJ/Nm3), dry gas yield of 2.04 and 2.0 (Nm3/kg), carbon conversion of 93% and 85 % and cold gas efficiency of 72% and 71 % were obtained for EFB and sawdust at the temperature of 1050 °C and ER of 0.25. However, it was realized that agglomeration was the major issue in EFB gasification at high temperatures. To prevent the bed agglomeration, EFB gasification was performed at temperature of 770±20 °C while the ER was varied from 0.17 to 0.32. Maximum HHV of 4.53 was obtained at ER of 0.21 where no agglomeration was observed.
    Matched MeSH terms: Calorimetry, Differential Scanning
  18. Karim AA, Toon LC, Lee VP, Ong WY, Fazilah A, Noda T
    J Food Sci, 2007 Mar;72(2):C132-8.
    PMID: 17995828
    Effects of phosphorus content (510 to 987 ppm) on the gelatinization and retrogradation of 6 potato cultivars (Benimaru, Hokkaikogane, Irish Cobbler, Konafubuki, Sakurafubuki, and Touya) were studied. Pasting properties were analyzed by RVA, thermal properties by DSC, and mechanical properties of the starch gels by TA. Phosphorus was positively correlated with swelling power (r= 0.84) and negatively correlated with solubility (r= 0.83). Phosphorus content showed significant effect on certain pasting properties of potato starch such as peak viscosity, breakdown, and setback. Phosphorus content showed a significant positive correlation with peak viscosity (r= 0.95) and breakdown (r= 0.90). Increasing concentration of phosphorus tends to decrease the setback. Phosphorus content had no influence on thermal properties and mechanical properties of potato starch gel.
    Matched MeSH terms: Calorimetry, Differential Scanning
  19. Saringat HB, Alfadol KI, Khan GM
    Pak J Pharm Sci, 2005 Jul;18(3):25-38.
    PMID: 16380341
    Coating has been widely used in pharmaceutical manufacture either as non-functional or a functional entity. The objectives of the present study were to investigate the effect of plasticizers such as PEG400, PEG1000 and triacetin on mechanical properties, glass transition temperature and water vapor transmission of free films prepared from HPMC and/or HPMC:PVA blends, to develop suitable coating system for tablets, and to determine the release profiles of the coated tablets. The tensile strength of plasticized HPMC films was generally lower than that of control HPMC film and could be attributed to increased crystallinity and segmental chain mobility of HPMC. This effect increased as the concentration of plasticizer increased. Generally the addition of both grades of polyethylene glycol (PEG400 & PEG1000) increased the moisture permeability of HPMC films but the films containing triacetin provided a more rigid barrier to moisture compared to unplasticized HPMC films. The dissolution profiles of paracetamol tablets coated with 7% w/v HPMC coating-solutions containing PEG400, PEG1000 and triacetin, and those containing PEG400 & PVA together showed that HPMC had weak water resistance. The presence of PEG400 and 1000 in HPMC films further weakened its resistance to solubility while the presence of triacetin caused a little increase in HPMC water resistance. From the results it was concluded that HPMC at 7%w/w concentration was suitable for film-coating intended for non-functional coating. Presence of the PEG 400, PEG1000 and triacetin as well as the presence of PVA and PEG400 together improved the coating properties of HPMC films and made it more suitable as a non-functional coating material.
    Matched MeSH terms: Calorimetry, Differential Scanning
  20. How CW, Rasedee A, Abbasalipourkabir R
    IEEE Trans Nanobioscience, 2013 Jun;12(2):72-8.
    PMID: 23268387 DOI: 10.1109/TNB.2012.2232937
    Nanostructured lipid carriers (NLC) composed of solid and liquid lipids, and surfactants are potentially good colloidal drug carriers. Before NLC can be used as drug carriers, the cytotoxicity of their components must be ascertained. The cytotoxicity of solid lipids (trilaurin, palmitin, docosanoid acid, and hydrogenated palm oil [HPO]) and surfactants (Polysorbate 20, 80, and 85) were determined on BALB/c 3T3 cells. The HPO and Polysorbate 80 were least cytotoxic and used with olive oil in the formulation of NLC. The particle size, polydispersity index, zeta potential, specific surface area, and crystallinity index of the NLC were 61.14 nm, 0.461, -25.4 mV, and 49.07 m(2) and 27.12% respectively, while the melting point was 4.3 °C lower than of HPO. Unlike in serum-free, NLC incubated in fetal bovine serum-supplemented medium did not show particle growth, suggesting that serum proteins in medium inhibit nanoparticles aggregation. The study also showed that NLC was less toxic to BALB/c 3T3 cells than Polysorbate 80. Thus, NLC with olive oil, HPO, and Polysorbate 80 as components are potentially good drug carriers with minimal cytotoxicity on normal cells.
    Matched MeSH terms: Calorimetry, Differential Scanning
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