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Ruiyun Zhang - One of the best experts on this subject based on the ideXlab platform.
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synthetic nano scale fibrous extracellular matrix
Journal of Biomedical Materials Research, 1999Co-Authors: Peter X, Ruiyun ZhangAbstract:Biodegradable polymers have been widely used as scaffolding materials to regenerate new tissues. To mimic natural extracellular matrix architecture, a novel highly po- rous structure, which is a three-dimensional interconnected fibrous network with a fiber diameter ranging from 50 to 500 nm, has been created from biodegradable aliphatic polyes- ters in this work. A porosity as high as 98.5% has been achieved. These nano-fibrous matrices were prepared from the polymer solutions by a procedure involving thermally induced Gelation, solvent exchange, and freeze-drying. The effects of polymer concentration, thermal annealing, solvent exchange, and freezing Temperature before freeze-drying on the nano-scale structures were studied. In general, at a high Gelation Temperature, a platelet-like structure was formed. At a low Gelation Temperature, the nano-fibrous structure was formed. Under the conditions for nano-fibrous matrix formation, the average fiber diameter (160-170 nm) did not change statistically with polymer concentration or Gelation Temperature. The porosity decreased with polymer concen- tration. The mechanical properties (Young's modulus and tensile strength) increased with polymer concentration. A surface-to-volume ratio of the nano-fibrous matrices was two to three orders of magnitude higher than those of fi- brous nonwoven fabrics fabricated with the textile technol- ogy or foams fabricated with a particulate-leaching tech- nique. This synthetic analogue of natural extracellular ma- trix combined the advantages of synthetic biodegradable polymers and the nano-scale architecture of extracellular matrix, and may provide a better environment for cell at- tachment and function. © 1999 John Wiley & Sons, Inc. J Biomed Mater Res, 46, 60-72, 1999.
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Synthetic nano-scale fibrous extracellular matrix
Journal of Biomedical Materials Research, 1999Co-Authors: Peter X. Ma, Ruiyun ZhangAbstract:Biodegradable polymers have been widely used as scaffolding materials to regenerate new tissues. To mimic natural extracellular matrix architecture, a novel highly porous structure, which is a three-dimensional interconnected fibrous network with a fiber diameter ranging from 50 to 500 nm, has been created from biodegradable aliphatic polyesters in this work. A porosity as high as 98.5% has been achieved. These nano-fibrous matrices were prepared from the polymer solutions by a procedure involving thermally induced Gelation, solvent exchange, and freeze-drying. The effects of polymer concentration, thermal annealing, solvent exchange, and freezing Temperature before freeze-drying on the nano-scale structures were studied. In general, at a high Gelation Temperature, a platelet-like structure was formed. At a low Gelation Temperature, the nano-fibrous structure was formed. Under the conditions for nano-fibrous matrix formation, the average fiber diameter (160-170 nm) did not change statistically with polymer concentration or Gelation Temperature. The porosity decreased with polymer concentration. The mechanical properties (Young's modulus and tensile strength) increased with polymer concentration. A surface-to-volume ratio of the nano-fibrous matrices was two to three orders of magnitude higher than those of fibrous nonwoven fabrics fabricated with the textile technology or foams fabricated with a particulate-leaching technique. This synthetic analogue of natural extracellular matrix combined the advantages of synthetic biodegradable polymers and the nano-scale architecture of extracellular matrix, and may provide a better environment for cell attachment and function.
Alan E Bell - One of the best experts on this subject based on the ideXlab platform.
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effects of Gelation Temperature on mozzarella type curd made from buffalo and cows milk 1 rheology and microstructure
Food Chemistry, 2012Co-Authors: Imtiaz Hussain, Alistair S Grandison, Alan E BellAbstract:The rheology and microstructure of Mozzarella-type curds made from buffalo and cows’ milk were measured at Gelation Temperatures of 28, 34 and 39 °C after chymosin addition. The maximum curd strength (G′) was obtained at a Gelation Temperature of 34 °C in both types of bovine milk. The viscoelasticity (tan δ) of both curds was increased with increasing Gelation Temperature. The rennet coagulation time was reduced with increase of Gelation Temperature in both types of milk. Frequency sweep data (0.1–10Hz was recorded 90 min after chymosin addition, and both milk samples showed characteristics of weak viscoelastic gel systems. When both milk samples were subjected to shear stress to break the curd system at constant shear rate, 95 min after chymosin addition, the maximum yield stress was obtained at the Gelation Temperatures of 34 °C and 28 °C in buffalo and cows’ curd respectively. The cryo-SEM and CLSM techniques were used to observe the microstructure of Mozzarella-type curd. The porosity was measured using image J software. The cryo-SEM and CLSM micrographs showed that minimum porosity was observed at the Gelation Temperature of 34 °C in both types of milk. Buffalo curd showed minimum porosity at similar Gelation Temperature when compared to cows’ curd. This may be due to higher protein concentration in buffalo milk.
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Effects of Gelation Temperature on Mozzarella-type curd made from buffalo and cows' milk: 2. Curd yield, overall quality and casein fractions.
Food chemistry, 2012Co-Authors: Imtiaz Hussain, Alistair S Grandison, Jen Yan, Alan E BellAbstract:The overall quality of Mozzarella-type curds made from buffalo and cows' milks were measured at Gelation Temperatures of 28, 34 and 39°C, and cutting times of 45, 60, 75 and 90min after chymosin addition. The curd yield and moisture content decreased with increasing Gelation Temperature, while whey fat losses increased. The effect of higher Gelation Temperature (39°C) was more pronounced in cows' milk than buffalo milk. This results in more fat losses and lower yields in both milk samples at a Gelation Temperature of 39°C. The minimum losses of fat and protein in rennet whey occurred at a Gelation Temperature of 34°C in both milk samples. The curd yield was higher in buffalo milk as compared to cows' milk. This is due to difference in total solids (fat and protein contents) of the two types of bovine milk. The different cutting times had a small effect on the yield and overall quality of curds made from both milk types. Curd moisture and loss tangent have a strong relationship with respect to effects of Gelation Temperature. Two different curd drainage methods (centrifugation and Buchner funnel filtration) were used to compare the final overall quality of Mozzarella-type curds made from both milk types. The α(s1) and β casein fractions were found to be in different proportions in the two milk types. The total- and casein bound-calcium were higher in buffalo milk than cows' milk. The total protein, casein and fat were also found to be higher in buffalo milk than cows' milk.
Hangon Choi - One of the best experts on this subject based on the ideXlab platform.
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novel dual reverse thermosensitive solid lipid nanoparticle loaded hydrogel for rectal administration of flurbiprofen with improved bioavailability and reduced initial burst effect
European Journal of Pharmaceutics and Biopharmaceutics, 2015Co-Authors: Fakhar Ud Din, Chul Soon Yong, Omer Mustapha, Dong Wuk Kim, Rehmana Rashid, Jong Hyuck Park, Ju Yeon Choi, Jong Oh Kim, Hangon ChoiAbstract:The purpose of this study was to develop novel solid lipid nanoparticle (SLN)-loaded dual-reverse thermosensitive hydrogel (DRTH) for rectal administration of flurbiprofen with improved bioavailability and reduced initial burst effect. The flurbiprofen-loaded SLNs were prepared by hot homogenisation technique, after optimising the amounts of lipid mixture (tricaprin and triethanolamine in 8:2 weight ratio), drug and surfactant. The flurbiprofen-loaded thermosensitive SLN composed of drug, lipid mixture and surfactant at a weight ratio of 10/15/1.3 was a solid at room Temperature, and changed to liquid form at physiological Temperature due to its melting point of about 32°C. This SLN gave the mean particle size of about 190nm and entrapment efficiency of around 90%. The DRTHs were prepared by adding this flurbiprofen-loaded thermosensitive SLN in various poloxamer solutions. Their rheological characterisation, release and stability were investigated while a morphological and pharmacokinetic study was performed after its rectal administration to rats compared with the drug and hydrogel. Poloxamer 188 and SLN decreased the Gelation Temperature and Gelation time, but increased the viscosity at 25°C, gel strength and mucoadhesive force of DRTHs. In particular, the DRTH composed of [SLN/P 407/P 188 (10%/15%/25%)] with the Gelation Temperature of about 35°C existed as liquid at room Temperature, but gelled at 30-36°C, leading to opposite reversible property of SLN. Thus, it was easy to administer rectally, and it gelled rapidly inside the body. This DRTH gave a significantly increased dissolution rate of the drug as compared to the flurbiprofen, but significantly retarded as compared to the hydrogel, including the initial dissolution rate. Moreover, this DRTH gave significantly higher plasma concentration and 7.5-fold AUC values compared to the drug, and lower initial plasma concentration and Cmax value compared to the hydrogel due to reduced initial burst effect. No damage in rectal mucosa was observed after the application of DRTH. Thus, this DRTH system with improved bioavailability and reduced initial burst effect would be recommended as an alternative for the flurbiprofen-loaded rectal pharmaceutical products.
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preparation of ibuprofen loaded liquid suppository using eutectic mixture system with menthol
European Journal of Pharmaceutical Sciences, 2004Co-Authors: Chul Soon Yong, Jongdal Rhee, Chongkook Kim, Se Hyun Jung, Hodong Kim, Hangon ChoiAbstract:Abstract To prepare an ibuprofen-loaded liquid suppository using eutectic mixture with menthol, the effects of menthol and poloxamer 188 (P 188) on the aqueous solubility of ibuprofen were investigated. The physicochemical properties such as Gelation Temperature, gel strength and bioadhesive force of various formulations composed of ibuprofen, menthol and P 188 were investigated. Then, the pharmacokinetic study of ibuprofen delivered by the liquid suppositories composed of P 188 and menthol were then performed. In the absence of P 188, the solubility of ibuprofen increased until the ratio of menthol to ibuprofen increased from 0:10 to 4:6 followed by an abrupt decrease in solubility above the ratio of 4:6, indicating that four parts of ibuprofen formed eutectic mixture with six parts of menthol. In the presence of P 188, the solutions with the same ratio showed abrupt increase in the solubility of ibuprofen. Furthermore, the solution with ratio of 4:6 showed more than 2.5- and 6-fold increase in the solubility of ibuprofen compared with that without additives and that without menthol, respectively. The poloxamer gel with menthol/ibuprofen ratio of 1:9 and higher than 15% poloxamer 188 showed the maximum solubility of ibuprofen, 1.2 mg/ml. Ibuprofen increased the Gelation Temperature and weakened the gel strength and bioadhesive force of liquid suppositories. However, menthol did the opposite due to forming the eutectic mixture with ibuprofen. The ibuprofen-loaded liquid suppository [P 188/menthol/ibuprofen (15/0.25/2.5%)] with the maximum ibuprofen solubility of 1.2 mg/ml was administered easily to the anus and to remain at the administered site without leakage after the dose. Furthermore, it gave significantly higher initial plasma concentrations, C max and AUC of ibuprofen than did solid suppository, indicating that the drug from poloxamer gel could be more absorbed than that from solid one in rats. Thus, the liquid suppository system with P 188 and menthol, a more convenient and effective rectal dosage form for ibuprofen will be expected to enhance the rectal bioavailability of ibuprofen.
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effect of sodium chloride on the Gelation Temperature gel strength and bioadhesive force of poloxamer gels containing diclofenac sodium
International Journal of Pharmaceutics, 2001Co-Authors: Chul Soon Yong, Jin Suck Choi, Qizhe Quan, Jongdal Rhee, Philsoo Oh, Hangon ChoiAbstract:Liquid suppository systems composed of poloxamers and bioadhesive polymers were easy to administer to the anus and mucoadhesive to the rectal tissues without leakage after the dose. However, a liquid suppository system containing diclofenac sodium could not be developed using bioadhesive polymers, since the drug was precipitated in this preparation. To develop a liquid suppository system using sodium chloride instead of bioadhesive polymers, the physicochemical properties such as Gelation Temperature, gel strength and bioadhesive force of various formulations composed of diclofenac sodium, poloxamers and sodium chloride were investigated. The mixtures of P 407 (15%) and P 188 (15-20%) existed as a liquid at room Temperature, but gelled at physiological Temperature. Diclofenac sodium significantly increased the Gelation Temperature and weakened the gel strength and bioadhesive force, while sodium chloride did the opposite. Furthermore, the poloxamer gels with less than 1.0% of sodium chloride, in which the drug was not precipitated, were inserted into the rectum of rabbits without difficulty and leakage, and retained in the rectum of rats for at least 6 h. Our results suggested that a thermosensitive liquid suppository system with sodium chloride and poloxamers was a more physically stable and convenient rectal dosage form for diclofenac sodium.
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effect of additives on the physicochemical properties of liquid suppository bases
International Journal of Pharmaceutics, 1999Co-Authors: Hangon Choi, Mikyung Lee, Moonhee Kim, Chongkook KimAbstract:To investigate the effects of additives on the physicochemical properties of in situ gelling and mucoadhesive liquid suppository base, Gelation Temperature, gel strength and bioadhesive force of liquid suppository base, poloxamer 407 (P 407) and poloxamer 188 (P 188) (15/15%) were evaluated in the presence of following additives: solvent (ethanol, propylene glycol, glycerin), ionic strength-controlling agent (sodium chloride) and pH-controlling agent (hydrochloric acid, sodium monohydrogen phosphate, sodium dihydrogen phosphate). Among the additives studied, sodium chloride, sodium monohydrogen phosphate and sodium dihydrogen phosphate increased to a great extent the gel strength and the bioadhesive force of P 407/P 188 (15/15%) with a decrease in Gelation Temperature. Glycerin slightly decreased the Gelation Temperature and slightly increased the gel strength and bioadhesive force. However, the addition of 1% of sodium chloride, sodium monohydrogen phosphate or sodium dihydrogen phosphate caused a greater than 60-fold increase in gel strength and over a tenfold increase in bioadhesive force with 2-4 degrees C decrease of Gelation Temperature within optimal range, compared with P 407/P 188 (15/15%) alone. On the other hand, ethanol, propylene glycol and hydrochloric acid increased the Gelation Temperature and slightly decreased the gel strength and the bioadhesive force. Taken together, these findings indicate that the effect of additives on the physicochemical properties of liquid suppository bases depends on their bonding capacities, in that additives such as sodium chloride, sodium monohydrogen phosphate and sodium dihydrogen phosphate having strong cross-linking bonds with the components of liquid suppository base increase the strength and bioadhesive force of a gel compared to liquid suppository base alone, while additives such as ethanol, propylene glycol and hydrochloric acid having weaker hydrogen bonding result in a weaker response. Thus, sodium chloride and sodium phosphates appear to be promising additives for in situ gelling and mucoadhesive liquid suppository base, if used in adequate amounts.
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development of in situ gelling and mucoadhesive acetaminophen liquid suppository
International Journal of Pharmaceutics, 1998Co-Authors: Hangon Choi, Jaehee Jung, Jeiman Ryu, Sungjune Yoon, Chongkook KimAbstract:Abstract Conventional suppositories are solid forms which often cause discomfort during insertion. The leakage of suppositories from the rectum also gives uncomfortable feelings to the patients. In addition, when the solid suppositories without mucoadhesivity reach the end of the colon, the drugs can undergo the first-pass effect. To solve these problems, we developed a novel in situ-gelling and mucoadhesive acetaminophen liquid suppository with Gelation Temperature at 30–36°C and suitable gel strength and bioadhesive force. Poloxamer 407 (P407) or/and poloxamer 188 (P188) were used to confer the Temperature-sensitive Gelation property. The mixtures of P407 (15%) and P188 (15–20%) existed as a liquid at room Temperature, but gelled at 30–36°C. Acetaminophen, the active ingredient of the suppositories, slightly increased Gelation Temperature, but significantly decreased gel strength and bioadhesive force. To modulate the gel strength and the bioadhesive force of acetaminophen liquid suppositories, bioadhesive polymers such as polyvinylpyrrolidone (PVP), hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), carbopol and polycarbophil were studied. The bioadhesive polymers exerted various impacts on the physicochemical properties of liquid suppositories. The Gelation Temperature was not significantly affected by PVP, HPMC and HPC, but decreased by carbopol and polycarbophil. Of bioadhesive polymers, carbopol and polycarbophil most significantly enhanced both gel strength and bioadhesive force. The liquid suppositories with carbopol or polycarbophil were inserted into the rectum of rats without difficulty and leakage and retained in the rectum for at least 6 h. These results suggest that in situ-gelling and mucoadhesive liquid suppository for humans can be further developed as a more convenient and effective rectal dosage form.
Imtiaz Hussain - One of the best experts on this subject based on the ideXlab platform.
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effects of Gelation Temperature on mozzarella type curd made from buffalo and cows milk 1 rheology and microstructure
Food Chemistry, 2012Co-Authors: Imtiaz Hussain, Alistair S Grandison, Alan E BellAbstract:The rheology and microstructure of Mozzarella-type curds made from buffalo and cows’ milk were measured at Gelation Temperatures of 28, 34 and 39 °C after chymosin addition. The maximum curd strength (G′) was obtained at a Gelation Temperature of 34 °C in both types of bovine milk. The viscoelasticity (tan δ) of both curds was increased with increasing Gelation Temperature. The rennet coagulation time was reduced with increase of Gelation Temperature in both types of milk. Frequency sweep data (0.1–10Hz was recorded 90 min after chymosin addition, and both milk samples showed characteristics of weak viscoelastic gel systems. When both milk samples were subjected to shear stress to break the curd system at constant shear rate, 95 min after chymosin addition, the maximum yield stress was obtained at the Gelation Temperatures of 34 °C and 28 °C in buffalo and cows’ curd respectively. The cryo-SEM and CLSM techniques were used to observe the microstructure of Mozzarella-type curd. The porosity was measured using image J software. The cryo-SEM and CLSM micrographs showed that minimum porosity was observed at the Gelation Temperature of 34 °C in both types of milk. Buffalo curd showed minimum porosity at similar Gelation Temperature when compared to cows’ curd. This may be due to higher protein concentration in buffalo milk.
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Effects of Gelation Temperature on Mozzarella-type curd made from buffalo and cows' milk: 2. Curd yield, overall quality and casein fractions.
Food chemistry, 2012Co-Authors: Imtiaz Hussain, Alistair S Grandison, Jen Yan, Alan E BellAbstract:The overall quality of Mozzarella-type curds made from buffalo and cows' milks were measured at Gelation Temperatures of 28, 34 and 39°C, and cutting times of 45, 60, 75 and 90min after chymosin addition. The curd yield and moisture content decreased with increasing Gelation Temperature, while whey fat losses increased. The effect of higher Gelation Temperature (39°C) was more pronounced in cows' milk than buffalo milk. This results in more fat losses and lower yields in both milk samples at a Gelation Temperature of 39°C. The minimum losses of fat and protein in rennet whey occurred at a Gelation Temperature of 34°C in both milk samples. The curd yield was higher in buffalo milk as compared to cows' milk. This is due to difference in total solids (fat and protein contents) of the two types of bovine milk. The different cutting times had a small effect on the yield and overall quality of curds made from both milk types. Curd moisture and loss tangent have a strong relationship with respect to effects of Gelation Temperature. Two different curd drainage methods (centrifugation and Buchner funnel filtration) were used to compare the final overall quality of Mozzarella-type curds made from both milk types. The α(s1) and β casein fractions were found to be in different proportions in the two milk types. The total- and casein bound-calcium were higher in buffalo milk than cows' milk. The total protein, casein and fat were also found to be higher in buffalo milk than cows' milk.
Dipankar Chattopadhyay - One of the best experts on this subject based on the ideXlab platform.
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effect of carrageenan and potassium chloride on an in situ gelling ophthalmic drug delivery system based on methylcellulose
RSC Advances, 2015Co-Authors: Biplab Bhowmick, Manas Bhowmik, Gunjan Sarkar, Dipak Rana, Nayan Ranjan Saha, Sushmita Ghosh, Dipankar ChattopadhyayAbstract:Our research is devoted to developing a methylcellulose (MC) based in situ gelling ophthalmic formulation using pilocarpine hydrochloride as a model drug, containing different proportions of i (iota)-carrageenan and potassium chloride. This study will evaluate the utility of the proposed formulation to be a substitute for traditional eye drops. Use of both i-carrageenan and potassium chloride of definite wt% effectively reduces the gel Temperature of the virgin MC solution from 60 °C to 33.5 °C which is below physiological Temperature. The conventional methods like test tube tilting, and viscosity measurements are used to determine the Gelation Temperature while the gels are subjected to swelling as well as a gel dissolution study. Subsequently, the outcome from in vitro and in vivo studies confirms that the present system may be a better alternative compared to conventional eye drops.
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effect of methyl cellulose on Gelation behavior and drug release from poloxamer based ophthalmic formulations
International Journal of Biological Macromolecules, 2015Co-Authors: Mitali Dewan, Mrinal Kanti Bain, Manas Bhowmik, Biplab Bhowmick, Gunjan Sarkar, Dipak Rana, Dipankar ChattopadhyayAbstract:Abstract The effect of weight average molecular weight ( M w ) of methyl cellulose (MC) on the Gelation behavior of Poloxamer 407 (PM) and in vitro release of Ketorolac Tromethamine (KT) from different ophthalmic formulations based on PM is examined. A drop of Gelation Temperature of PM is observed using MC of various M w by test tube tilting method, UV–vis spectroscopy, viscometry and rheometry. It is also observed that the viscosity and gel strength of all the formulations are increased with the increase in M w of MC. PM with highest M w of MC provides best drug release property among all the formulations. It is evident from this investigation that there is a distinct effect of M w of MC on the Gelation behavior of PM as well as on the drug release profile of KT from PM–MC based ophthalmic formulations.
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effect of peg salt mixture on the Gelation Temperature and morphology of mc gel for sustained delivery of drug
Carbohydrate Polymers, 2013Co-Authors: Mrinal Kanti Bain, Manas Bhowmik, Dipanwita Maity, Biplab Bhowmick, Gunjan Sarkar, Dipak Rana, Dibyendu Mondal, Md Masud Rahaman Mollick, Dipankar ChattopadhyayAbstract:Abstract Gelation Temperature of MC was reduced from 59 °C to 54 °C with the addition of 10% PEG. Sodium tartrate (NaT) and sodium citrate (NaC) were added to the MC–PEG solution to further reduce the Gelation Temperature close to physiological Temperature. Different techniques were used to measure the Gelation Temperature of all formulations. It was observed that NaC was more effective in reducing the Gelation Temperature of MC–PEG combination than NaT. Environmental scanning electron microscopy (ESEM) images of hydrogels containing NaC and NaT showed that NaC containing hydrogel having an interconnected microporous structure instead of the hollow rod like structure as in the case of NaT containing hydrogel. In vitro drug release studies showed that drug release time increased from 6 to 9 h by only changing the type of salt from NaT to NaC in MC–PEG combination.
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synergistic effect of salt mixture on the Gelation Temperature and morphology of methylcellulose hydrogel
International Journal of Biological Macromolecules, 2012Co-Authors: Mrinal Kanti Bain, Dipanwita Maity, Biplab Bhowmick, Dipak Rana, Dibyendu Mondal, Md Masud Rahaman Mollick, Dipankar ChattopadhyayAbstract:Gelation Temperature of methylcellulose (MC) can be altered by adding different additives. Pure MC showed sol-gel transition at 60°C. Sodium citrate and sodium tartrate were used alone and in combination to see the effect of individual salt and combination of salts on the Gelation Temperature of MC. The Gelation Temperature of all the binary and ternary combinations of MC and salts were measured with different methods such as test tube tilting method (TTM), UV-vis spectroscopy, viscometry, and by rheometer and also the morphology of gels were characterized with the help of environmental scanning electron microscopy (ESEM). It was observed that when 0.1 M sodium citrate (NaC) and 0.1 M sodium tartrate (NaT) were used separately, the Gelation Temperature of MC was reduced up to 44°C and 47°C respectively but when mixture of NaC and NaT (0.1 (M) NaC and 0.1 (M) (NaT)) were used the Gelation Temperature was further reduced to 36°C. It was clear from ESEM images that when NaC and NaT were used separately the formation of network was not distinguishable. But, well-connected network structure was observed when a mixture 0.1 M NaC and 0.1 M NaT was used.
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control of thermo reversible Gelation of methylcellulose using polyethylene glycol and sodium chloride for sustained delivery of ophthalmic drug
Journal of Applied Polymer Science, 2010Co-Authors: Mrinal Kanti Bain, Manas Bhowmik, Dipanwita Maity, Nirmal Kumar Bera, Santinath Ghosh, Dipankar ChattopadhyayAbstract:The effect of molecular weight of polyethyl- eneglycol (PEG) and sodium chloride (NaCl) on the gela- tion Temperature of methylcellulose (MC) was studied with the objective to develop a MC based formulation for sustained delivery of ophthalmic drug. The Gelation tem- perature of 1% MC was 60 6 0.40 � C. It was found that the Gelation Temperature of MC was reduced with the addi- tion of 10% PEG and extent of reduction of Gelation tem- perature was depended on the molecular weight of PEG at same PEG concentration of 10%. The Gelation tempera- ture of MC was reduced by 10.4 to 5.9 � C with the increas- ing molecular weight of PEG starting from 400 to 20,000 (Mn) depending on the method of determination of gela- tion Temperature. To reduce the Gelation Temperature of MC close to physiological Temperature (37 � C), 6% NaCl was added in the different MC-PEG combinations contain- ing different molecular weight of PEG. It was observed that the drug release time increased from 5 to 8 h with the increase in molecular weight of PEG from 400 to 20,000 (Mn) and this was due to the maximum viscosity and gel strength of MC-PEG20000-NaCl ternary combination. V C 2010