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RISS 인기검색어
- 검색키워드
- 저자 : ( Roshan Pradhan ) (검색결과 24 건)
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Roshan Pradhan,Tuan Hiep Tran,최주연,최임순,최한곤,용철순,김종오 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.4
The purpose of this study was to improve thegastric solubility and bioavailability of rebamipide (RBM)by preparing the RBM solid dispersion tablet (RBM-SDT)from solid dispersion powder prepared by spray-dryingtechnique. For preparation of rebamipide solid dispersions(RBM-SDs), solubility study was performed in varioushydrophilic carriers and alkalizers, among which sodiumalginate and sodium carbonate were selected as thehydrophilic polymer and alkalizer, respectively. Differentcombinations of drug–polymer–alkalizer were dissolved inaqueous solution and spray-dried in order to obtain soliddispersions. Noticeable improvement in aqueous solubility(approximately 200 times) and in vitro dissolution rate wasobserved by RBM-SDs, compared to RBM powder. Theoptimized formulation of RBM-SD powder consisted ofRBM powder/sodium alginate/sodium carbonate at theweight ratio of 1/2/2. The transformation of crystallineRBM to amorphous RBM-SD powder was clearly demonstratedby powder X-ray diffraction, differential scanningcalorimetry (DSC) and scanning electron microscopy. The optimized RBM-SD was formulated in tablet dosageform, containing approximately 2 % sodium lauryl sulphateand poloxamer F68 as wetting agents. The RBMSDTexhibited enhanced dissolution in hydrochloric acidbuffer (pH 1.2) and distilled water. Moreover, pharmacokineticstudy in rats showed higher AUC and Cmax forRBM-SDT than those for RBM powder and commercialproduct. Thus, the developed RBM-SDT formulation canbe more efficacious for improving oral bioavailability ofRBM.
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Roshan Pradhan,Bijay Kumar Poudel,최주연,최임순,신범수,최한곤,용철순,김종오 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.5
In the present study, we developed the novel17-allyamino-17-demethoxygeldanamycin (17-AAG)-loadedpoly(lactic acid-co-glycolic acid) (PLGA) nanoparticles(NPs) using the combination of sodium lauryl sulfateand poloxamer 407 as the anionic and non-ionic surfactantfor stabilization. The PLGA NPs were prepared by emulsification/solvent evaporation method. Both the drug/polymer ratio and phase ratio were 1:10 (w/w). The optimizedformulation of 17-AAG-loaded PLGA NPs had aparticle size and polydispersity index of 151.6 ± 2.0 and0.152 ± 0.010 nm, respectively, which was further supportedby TEM image. The encapsulation efficiency anddrug loading capacity were 69.9 and 7.0 %, respectively. In vitro release study showed sustained release. Whenin vitro release data were fitted to Korsmeyer–Peppasmodel, the n value was 0.468, which suggested that thedrug was released by anomalous or non-Fickian diffusion. In addition, 17-AAG-loaded PLGA NPs in 72 h, displayedapproximately 60 % cell viability reduction at 10 lg/ml17-AAG concentration, in MCF-7 cell lines, indicatingsustained release from NPs. Therefore, our resultsdemonstrated that incorporation of 17-AAG into PLGANPs could provide a novel effective nanocarrier for thetreatment of cancer.
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Roshan Pradhan,이희현,김정옥,문성옥,최혜민,김정범,용철순,이화동,김종오 한국약제학회 2015 Journal of Pharmaceutical Investigation Vol.45 No.5
The aim of this study was to develop a hydrophilic matrix based controlled release gastroretentive drug delivery system (GRDDS) for Samchulkunbi-tang (ST), a traditional Korean herbal medicine widely used for treatment of chronic gastritis and gastric ulcers. Effervescent floating GRDDS of ST was prepared by non-aqueous wet granulation method. Hydroxypropyl methylcellulose 2208 (100,000 cps) was used as the hydrophilic polymer, while the combination of sodium bicarbonate (NaHCO3) and citric acid was used as the gas-generating agents. Formulation optimization was done by altering the amount of polymer and floating aid, keeping the tablet weight constant. Tablet properties including floating lag time (FLT), total floating time (TFT) and swelling index were measured to determine the optimized formulation. Scanning electron microscopy analysis revealed the surface morphology of the swollen tablet with concomitant gas bubbles. Optimized formulation showed satisfactory controlled in vitro drug release for more than 8 h with excellent buoyancy properties (FLT of 30 s, TFT >12 h). Therefore, the developed formulation of ST in the form of a floating tablet would provide effective gastroprotection and can be a promising approach to delivery of the drug in the upper gastrointestinal tract.
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Pradhan, Roshan,Kim, Yong-Il,Jeong, Jee-Heon,Choi, Han-Gon,Yong, Chul Soon,Kim, Jong Oh Pharmaceutical Society of Japan 2014 Chemical & pharmaceutical bulletin Vol. No.
<P>Doxorubicin (DOX)-loaded water-in-oil-in-water (W/O/W) microemulsions were produced using a shirasu-porous-glass (SPG) membrane emulsification technique. Soybean oil was used as the oil phase; polyglycerol polyricinoleate (PGPR) or tetraglycerol polyricinoleate (TGPR) was used as the surfactant to stabilize the feed W/O emulsions, while Tween 20 was used in the external water phase to stabilize oil droplets containing water droplets. Increasing the feed pressure from 50 to 90?kPa increased the particle size of W/O/W emulsions, whereas it was decreased by increasing the agitator speed. The smallest particle sizes of multiple emulsions were obtained at the feed pressure of 50?kPa and agitator speed of 350?rpm. Under this set of conditions, the increase in the concentration of PGPR or TGPR showed a decrease in the particle size of DOX-loaded W/O/W emulsions. The optimized formulation comprising of 5% w/v PGPR and 3% w/v Tween 20 in the oil phase and external water phase, respectively, with 0.5% w/v of DOX had a particle size of 0.4400.007??m and polydispersity index of 0.2200.087, which was supported by the transmission electron microscopy image. The formulations showed a sustained release profile in phosphate buffer solution (pH 7.4). The plasma concentrations of DOX after intravenous administration to rats were prolonged and gave approximately 17-fold higher area under the drug concentration-time curve (AUC) compared to free DOX solution. Thus, these results demonstrated that the SPG membrane emulsification technique could be used as a promising technique to prepare W/O/W microemulsions for delivering DOX with sustained release characteristics and better bioavailability.</P>
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Fabrication of a uniformly sized fenofibrate microemulsion by membrane emulsification
Pradhan, Roshan,Lee, Dong Won,Choi, Han-Gon,Yong, Chul Soon,Kim, Jong Oh Informa UK, Ltd. 2013 Journal of microencapsulation Vol.30 No.1
<P>Fenofibrate-loaded microemulsions composed of Labrafil M 1944 CS, Capryol PGMC and fenofibrate as the dispersed phase and Labrasol in demineralised water as the continuous phase were prepared by utilising a Shirasu-porous-glass (SPG) membrane emulsification technique. The process parameters were optimised by adjusting the feed pressure (15-45 kPa), agitator speed (250-800 rpm) and temperature of the continuous phase (25-45°C). As a result, narrowly distributed microemulsions were obtained via SPG membrane emulsification at an agitator speed of 250 rpm, a feed pressure of 30 kPa and a continuous phase temperature of 25°C. Furthermore, TEM images clearly showed that the microemulsion prepared by SPG membrane emulsification had a uniform, spherical morphology with a narrow size distribution. Our results indicated that the SPG membrane emulsification technique is highly efficient for the preparation of narrowly distributed microemulsions with relatively smaller particle sizes compared with the common stirring method.</P>
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( Roshan Pradhan ),( Yong Il Kim ),( Jee Heon Jeong ),( Han Gon Choi ),( Chul Soon Yong ),( Jong Oh Kim ) 영남대학교 약품개발연구소 2015 영남대학교 약품개발연구소 연구업적집 Vol.25 No.-
Doxorubicin (DOX)-loaded water-in-oil-in-water (W/O/W) microemulsions were produced using a shirasu.porous.glass (SPG) membrane emulsification technique. Soybean oil was used as the oil phase; polyglycerol polyricinoleate (PGPR) or tetraglycerol polyricinoleate (TGPR) was used as the surfactant to stabilize the feed W/O emulsions, while Tween 20 was used in the external water phase to stabilize oil droplets containing water droplets. Increasing the feed pressure from 50 to 90 kPa increased the particle size of W/O/W emulsions, whereas it was decreased by increasing the agitator speed. The smallest particle sizes of multiple emulsions were obtained at the feed pressure of 50 kPa and agitator speed of 350 rpm. Under this set of conditions, the increase in the concentration of PGPR or TGPR showed a decrease in the particle size of DOX-loaded W/O/W emulsions. The optimized formulation comprising of 5% w/v PGPR and 3% w/v Tween 20 in the oil phase and external water phase, respectively, with 0.5% w/v of DOX had a particle size of 0.440 0.007 μm and polydispersity index of 0.220 0.087, which was supported by the transmission electron microscopy image. The formulations showed a sustained release profile in phosphate buffer solution (pH 7.4). The plasma concentrations of DOX after intravenous administration to rats were prolonged and gave approximately 17-fold higher area under the drug concentration.time curve (AUC) compared to free DOX solution. Thus, these results demonstrated that the SPG membrane emulsification technique could be used as a promising technique to prepare W/O/W microemulsions for delivering DOX with sustained release characteristics and better bioavailability.
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Pradhan, Roshan,Poudel, Bijay Kumar,Ramasamy, Thiruganesh,Choi, Han-Gon,Yong, Chul Soon,Kim, Jong Oh American Scientific Publishers 2013 Journal of nanoscience and nanotechnology Vol.13 No.8
<P>In the present study, we developed novel docetaxel (DTX)-loaded polylactic acid-co-glycolic acid (PLGA) nanoparticles (NPs) using the combination of sodium lauryl sulfate (SLS) and poloxamer 407, the anionic and non-ionic surfactants respectively for stabilization. The NPs were prepared by emulsification/solvent evaporation method. The combination of these surfactants at weight ratio of 1:0.5 was able to produce uniformly distributed small sized NPs and demonstrated the better stability of NP dispersion with high encapsulation efficiency (85.9 +/- 0.6%). The drug/polymer ratio and phase ratio were 2:10 and 1:10, respectively. The optimized formulation of DTX-loaded PLGA NPs had a particle size and polydispersity index of 104.2 +/- 1.5 nm and 0.152 +/- 0.006, respectively, which was further supported by TEM image. In vitro release study was carried out with dialysis membrane and showed 32% drug release in 192 h. When in vitro release data were fitted to Korsmeyer-Peppas model, the n value was 0.481, which suggested the drug was released by anomalous or non-Fickian diffusion. In addition, DTX-loaded PLGA NPs in 72 h, displayed approximately 75% cell viability reduction at 10 microg/ml DTX concentration, in MCF-7 cell lines, indicating sustained release from NPs. Therefore, our results demonstrated that incorporation of DTX into PLGA NPs could provide a novel effective nanocarrier for the treatment of cancer.</P>
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( Roshan Pradhan ),( Bijay Kumar Poudel ),( Thiruganesh Ramasamy ),( Han Gon Choi ),( Chul Soon Yong ),( Jong Oh Kim ) 영남대학교 약품개발연구소 2013 영남대학교 약품개발연구소 연구업적집 Vol.23 No.0
In the present study, we developed novel docetaxel (DTX)-loaded polylactic acid-co-glycolic acid(PLGA) nanoparticles (NPs) using the combination of sodium lauryl sulfate (SLS) and poloxamer 407, the anionic and non-ionic surfactants respectively for stabilization. The NPs were prepared by emulsification/solvent evaporation method. The combination of these surfactants at weight ratio of 1:0.5 was able to produce uniformly distributed small sized NPs and demonstrated the better stability of NP dispersion with high encapsulation efficiency (85.9 +/- 0.6%). The drug/polymer ratio and phase ratio were 2:10 and 1:10, respectively. The optimized formulation of DTX-loaded PLGA NPs had a particle size and polydispersity index of 104.2 +/- 1.5 nm and 0.152 +/- 0.006, respectively, which was further supported by TEM image. In vitro release study was carried out with dialysis membrane and showed 32% drug release in 192 h. When in vitro release data were fitted to Korsmeyer-Peppas model, the n value was 0.481, which suggested the drug was released by anomalous or non-Fickian diffusion. In addition, DTX-loaded PLGA NPs in 72 h, displayed approximately 75% cell viability reduction at 10 microg/ml DTX concentration, in MCF-7 cell lines, indicating sustained release from NPs. Therefore, our results demonstrated that incorporation of DTX into PLGA NPs could provide a novel effective nanocarrier for the treatment of cancer.
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Fabrication of a uniformly sized fenofibrate microemulsion by membrane emulsification
( Roshan Pradhan ),( Dong Won Lee ),( Han Gon Choi ),( Chul Soon Yong ),( Jong Oh Kim ) 영남대학교 약품개발연구소 2013 영남대학교 약품개발연구소 연구업적집 Vol.23 No.0
Fenofibrate-loaded microemulsions composed of Labrafil M 1944 CS, Capryol PGMC and fenofibrate as the dispersed phase and Labrasol in demineralised water as the continuous phase were prepared by utilising a Shirasu-porous-glass (SPG) membrane emulsification technique. The process parameters were optimised by adjusting the feed pressure (15-45 kPa), agitator speed (250-800 rpm) and temperature of the continuous phase (25-45°C). As a result, narrowly distributed microemulsions were obtained via SPG membrane emulsification at an agitator speed of 250 rpm, a feed pressure of 30 kPa and a continuous phase temperature of 25°C. Furthermore, TEM images clearly showed that the microemulsionprepared by SPG membrane emulsification had a uniform, spherical morphology with a narrow size distribution. Our results indicated that the SPGmembrane emulsification technique is highly efficient for the preparation of narrowly distributed microemulsions with relatively smaller particle sizes compared with the common stirring method.
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