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1.
The purpose of this research was to study the influence of type of chitosan with different molecular weights, ie, 190 and
419 kDa, on properties of pellets prepared by extrusion/ spheronization. The formulations, consisting of acetaminophen as
model drug, chitosan, microcrystalline cellulose (MCC), and dibasic calcium phosphate dihydrate with/without sodium alginate,
were extruded using a twin-screw extruder and water as the granulating liquid. With 30% wt/wt MCC and no added sodium alginate,
spherical pellets were produced containing low and high molecular weight chitosan at a maximum amount of 60% and 40% wt/wt,
respectively. With sodium alginate (2.5% wt/wt), pellets with either type of chitosan (60% wt/wt), MCC (17.5% wt/wt), and
acetaminophen (20% wt/wt) could be produced indicating an improved pelletforming ability. Type and amount of chitosan and
added sodium alginate affected physical properties of pellets including size, roundness, crushing force, and drug release.
Low molecular weight chitosan produced pellets with higher mean diameter, sphericity, and crushing force. Additionally, the
pellets made of low molecular weight chitosan and added sodium alginate showed faster drug release in 0.1 N HCl but had slower
drug release in pH 7.4 phosphate buffer. This indicated that drug release from pellets could be modified by the molecular
weight of chitosan. In conclusion, the molecular weight of chitosan had a major influence on formation, physical properties,
and drug release from the obtained pellets.
Published: August 10, 2007 相似文献
2.
Worawut Kriangkrai Satit Puttipipatkhachorn Pornsak Sriamornsak Thaned Pongjanyakul Srisagul Sungthongjeen 《AAPS PharmSciTech》2014,15(6):1357-1369
Tackiness caused by the gas-entrapped membrane (Eudragit®RL 30D) was usually observed during storage of the effervescent floating tablets, leading to failure in floatation and sustained release. In this work, common anti-tacking agents (glyceryl monostearate (GMS) and talc) were used to solve this tackiness problem. The impact of anti-tacking agent on the properties of free films and corresponding floating tablets was investigated. GMS was more effective than talc in reducing tackiness of the film. Addition and increasing amount of anti-tacking agents lowered the film mechanical strength, but the coating films were still strong and flexible enough to resist the generated gas pressure inside the floating tablet. Wettability and water vapor permeability of the film decreased with increasing level of anti-tacking agents as a result of their hydrophobicity. No interaction between anti-tacking agents and polymer was observed as confirmed by Fourier transform infrared spectroscopy, powder X-ray diffractometry, and differential scanning calorimetry studies. Increasing amount of anti-tacking agents decreased time to float and tended to retard drug release of the floating tablets. Floating properties and drug release were also influenced by type of anti-tacking agents. The obtained floating tablets still possessed good floating properties and controlled drug release even though anti-tacking agent had some effects. The results demonstrated that the tackiness problem of the floating tablets could be solved by incorporating anti-tacking agent into the gas-entrapped membrane.KEY WORDS: anti-tacking agent, coating film, controlled release, effervescent floating tablets, Eudragit®RL 30D 相似文献
3.
The purpose of this work was to investigate the effect of different polysulfonate resins and direct compression fillers on
physical properties of multiple-unit sustained-release dextromethorphan (DMP) tablets. DMP resinates were formed by a complexation
of DMP and strong cation exchange resins, Dowex 50 W and Amberlite IRP69. The tablets consisted of the DMP resinates and direct
compression fillers, such as microcrystalline cellulose (MCC), dicalcium phosphate dihydrate (DCP), and spray-dried rice starch
(SDRS). Physical properties of tablets, such as hardness, disintegration time, and in vitro release, were investigated. A
good performance of the tablets was obtained when MCC or SDRS was used. The use of rod-like and plate-like particles of Amberlite
IRP69 caused a statistical decrease in tablet hardness, whereas good tablet hardness was obtained when spherical particle
of Dowex 50 W was used. The plastic deformation of the fillers, such as MCC and SDRS, caused a little change in the release
of DMP. A higher release rate constant was found in the tablets containing DCP and Dowex 50 W, indicating the fracture of
the resinates under compression, which was attributable to the fragmentation of DCP. However, the release of DMP from the
tablets using Amberlite IRP69 was not significantly changed because of the higher degree of cross-linking of the resinates,
which exhibited more resistance to deformation under compression. In conclusion, the properties of polysulfonate resin, such
as particle shape and degree of cross-linking, and the deformation under compaction of fillers affect the physical properties
and the drug release of the resinate tablets.
Published: September 30, 2005. 相似文献
4.
Paula Lima Uthaiwan Kovitvadhi Satit Kovitvadhi Jorge Machado 《Invertebrate Biology》2006,125(1):34-44
Abstract. Larvae of the freshwater swan mussel, Anodonta cygnea , were cultured in artificial media at the controlled temperature of 23°±2°C, with successful metamorphosis for the first time. The artificial medium contained a mixture of M199, common carp plasma, and antibiotics/antimycotics. Glochidia were reared to the juvenile stage in the medium after 10–11 d of culture. After 15 d of controlled feeding with phytoplankton, the juveniles showed an elongated shell with several growth lines. Larval survival was 34.3±9.3%, whereas the proportion undergoing metamorphosis was ≤60.8±4.2%. The ultrastructure of early developmental stages was observed by scanning electron microscopy, from the glochidial to the juvenile stage. Glochidia had a hooked shell, with two equal triangular valves formed by a calcareous layer with numerous pores and covered by a thin cuticle of chitin–keratin. The appearance of the complete foot within 11 d of in vitro culture was considered the final feature of metamorphosis to the juvenile stage. The main alteration during juvenile development was the formation, under the glochidial shell, of a new periostracum with growth lines. The prominent foot, gradually covered by long, dense cilia, showed rhythmical movements involved in the capture of particulate matter. Similarly, cilia and microvilli present in the mantle also performed the same role. Longer cilia, sparsely distributed in the mantle, may function as chemotactile sensors. 相似文献
5.
Sungthongjeen S Sriamornsak P Pitaksuteepong T Somsiri A Puttipipatkhachorn S 《AAPS PharmSciTech》2004,5(1):50-57
The aim of this work was to assess the effect of 2 formulation variables, the pectin type (with different degrees of esterification
[DEs]) and the amount of calcium, on drug release from pectin-based matrix tablets. Pectin matrix tablets were prepared by
blending indomethacin (a model drug), pectin powder, and various amounts of calcium acetate and then tableting by automatic
hydraulic press machine. Differential scanning calorimetry, powder x-ray diffraction, and Fourier transformed-infrared spectroscopy
studies of the compressed tablets revealed no drug-polymer interaction and the existence of drug with low crystallinity. The
in-vitro release studies in phosphate buffer (United States Pharmacopeia) and tris buffer indicated that the lower the DE, the greater the time for 50% of drug release (T50). This finding is probably because of the increased binding capacity of pectin to calcium. However, when the calcium was
excluded, the pectins with different DEs showed similar release pattern with insignificant difference of T50. When the amount of calcium acetate was increased from 0 to 12 mg/tablet, the drug release was significantly slower. However,
a large amount of added calcium (ie, 24 mg/tablet) produced greater drug release because of the partial disintegration of
tablets. The results were more pronounced in phosphate buffer, where the phosphate ions induced the precipitation of calcium
phosphate. In conclusion, both pectin type and added calcium affect the drug release from the pectin-based matrix tablets. 相似文献
6.
Onanong Nuchuchua Usawadee Sakulku Napaporn Uawongyart Satit Puttipipatkhachorn Apinan Soottitantawat Uracha Ruktanonchai 《AAPS PharmSciTech》2009,10(4):1234-1242
The nanoemulsions composed of citronella oil, hairy basil oil, and vetiver oil with mean droplet sizes ranging from 150 to
220 nm were prepared and investigated both in vitro and in vivo. Larger emulsion droplets (195–220 nm) shifted toward a smaller size (150–160 nm) after high-pressure homogenization and
resulted in higher release rate. We proposed that thin films obtained from the nanoemulsions with smaller droplet size would
have higher integrity, thus increasing the vaporization of essential oils and subsequently prolonging the mosquito repellant
activity. The release rates were fitted with Avrami’s equations and n values were in the same range of 0.6 to 1.0, implying that the release of encapsulated limonene was controlled by the diffusion
mechanism from the emulsion droplet. By using high-pressure homogenization together with optimum concentrations of 5% (w/w) hairy basil oil, 5% (w/w) vetiver oil (5%), and 10% (w/w) citronella oil could improve physical stability and prolong mosquito protection time to 4.7 h due to the combination of
these three essential oils as well as small droplet size of nanoemulsion. 相似文献
7.
Sajomsang W Gonil P Ruktanonchai UR Pimpha N Sramala I Nuchuchua O Saesoo S Chaleawlert-umpon S Puttipipatkhachorn S 《International journal of biological macromolecules》2011,48(4):589-595
Water-soluble β-cyclodextrin grafted with chitosan (CD-g-CS) was carried out by quaternizing the CD-g-CS with glycidyltrimethyl ammonium chloride (GTMAC) under mild acidic condition, corresponding to the quaternized CD-g-CS (QCD-g-CS). The degrees of substitution (DS) and quaternization (DQ), ranging from 5% to 23% and 66% to 80%, respectively, were determined by (1)H NMR spectroscopy. Self-aggregates formation of all QCD-g-CSs were investigated in water using dynamic light scattering (DLS), atomic force microscopy (AFM), and transmission electron microscopy (TEM) techniques. The result revealed that all QCD-g-CSs are able to form self-aggregates in water. Large particle sizes ranged from 800 to 3000nm were obtained by DLS while zeta-potentials were ranging from 25 to 40mV. AFM and TEM depicted a spherical shape with particle sizes ranging from 100 to 900nm. Mucoadhesive and cytotoxic properties of all QCD-g-CSs were evaluated using a mucin particle method and MTT assay compared to quaternized chitosan (QCS). It was found that the mucoadhesive property increased with decreasing DS due to less quaternary ammonium moiety into the chitosan backbone. On the other hand, the cytotoxicity increased with increasing DS even though the DQ is decreased. 相似文献
8.
Rungsardthong Ruktanonchai U Srinuanchai W Saesoo S Sramala I Puttipipatkhachorn S Soottitantawat A 《Bioscience, biotechnology, and biochemistry》2011,75(12):2340-2345
The complexation between two isomers of citral in lemongrass oil and varying types of cyclodextrins (CDs), α-CD, β-CD, and HP-β-CD, were studied by molecular modeling and physicochemical characterization. The results obtained revealed that the most favorable complex formation governing between citrals in lemongrass oil and CDs were found at a 1:2 mole ratio for all CDs. Complex formation between E-citral and CD was more favorable than between Z-citral and CD. The thermal stability of the inclusion complex was observed compared to the citral in the lemongrass oil. The release time course of citral from the inclusion complex was the diffusion control, and it correlated well with Avrami's equation. The release rate constants of the E- and Z-citral inclusion complexes at 50 °C, 50% RH were observed at 1.32×10(-2) h(-1) and 1.43×10(-2) h(-1) respectively. 相似文献
9.
Pramote Chumnanpuen Kannika Chatchavalvanich Amara Thongpan Satit Kovitvadhi 《Invertebrate reproduction & development.》2013,57(1):40-52
The morphological development and the sequence of organogenesis from glochidium to the early juvenile stage of the freshwater pearl mussel, Hyriopsis bialatus, were observed. Larvae of H. bialatus were cultured in standard tissue culture medium (M199) supplemented with common carp (Cyprinus carpio) plasma and they showed transformation within 10 days. Larval samples were collected every 2 days during glochidia development and subjected to histological processing. Three types of cell masses were developed during this period: the ventral plate (the foot rudiment), lateral pits (the gill rudiment), and the oral plate or endodermic sac (the origin of the digestive tract). The ventral plate gave rise to two foot lobes which fused into a single lobe. The gills were developed from the lateral pits next to the ventral plate, forming a pair of gill buds that became elongated and turned into gill bars. The digestive tract began with the formation of mouth by invagination of the oral plate (or endodermic sac) and formation of a tube underneath the growing foot. Several controversial aspects of organogenesis have been inferred, e.g., de novo formation of the anterior and posterior juvenile adductors, the fate of the mushroom body structure, and foot lobe formation from two separate precursor lobes. A mushroom body protruded into the mantle cavity and remained there throughout the transformation period. Moreover, the evidence of a supporting band (mucoid structure) in the mature glochidium of H. bialatus has never been reported in other freshwater mussel species, and its function and composition need to be further investigated. 相似文献
10.
Koson Yingsukwattana Satit Puttipipatkhachorn Uracha Ruktanonchai 《Journal of liposome research》2016,26(1):69-79
Context: Oral delivery of peptide and protein drugs still remains the area of challenges due to their low stability and permeability across GI tract. Among numerous attempts, the receptor-mediated drug targeting is a promising approach to enhance GI permeability.Objective: The aim of this study was to prepare mannosylated buserelin acetate (MANS-BA) proliposome powders grafted with N-octadecyl-d-mannopyranosylamine (SAMAN) as targeting moiety and evaluate their permeability across Caco-2 cell monolayers.Materials and methods: The MANS-BA proliposome powders were prepared by coprecipitation method. The targeting moiety SAMAN was synthesized in-house and confirmed by characterization using Fourier transform infrared (FTIR) and differential scanning calorimeter (DSC).Results: The MANS-BA liposomes reconstituted from proliposome powders exhibited the oligolamellar vesicular structure of phospholipid bilayer. Their size, zeta potential and entrapment efficiency were in the ranges of 93.11–218.95?nm, ?24.03 to ?37.15?mV and 21.12–33.80%, respectively. The permeability of reconstituted MANS-BA liposomes across Caco-2 cell monolayers was significantly enhanced to about 1.2- and 2.2-fold over those of conventional BA liposomes and solution, respectively.Discussion: Increase in dicetylphosphate, cholesterol and SAMAN contents resulted in significant increase in size and zeta potential of reconstituted MAN-BA liposomes. The entrapment efficiency was increased with increasing dicetylphosphate and mannitol contents in liposomes containing cholesterol.Conclusions: The significantly enhanced permeability across Caco-2 cell monolayers of MANS-BA liposomes might be due to the role of mannose receptor on intestinal enterocytes. 相似文献