Current Issue : April - June Volume : 2017 Issue Number : 2 Articles : 5 Articles
The aim of this study was to prepare a solid dispersion formulation of curcumin to\nenhance its solubility, dissolution rate, and oral bioavailability. The formulation was prepared with\nD-�±-tocopheryl polyethylene glycol 1000 succinate (TPGS) and mannitol using solvent evaporation\nand freeze-drying methods, which yielded a solid dispersion composed of curcumin, TPGS,\nand mannitol at a ratio of 1:10:15 (w/w/w). The solubility and dissolution rate of the curcumin solid\ndispersion markedly improved compared with those of curcumin powder and a physical mixture of\ncurcumin, TPGS, and mannitol. About 90% of the curcumin was released from the solid dispersion\nformulation within 10 min. After administering the formulation orally to rats, higher plasma\nconcentrations of curcumin were observed, with increases in the maximum plasma concentration\n(Cmax) and area under the plasma concentration-time curve (AUC) of 86- and 65-fold, respectively,\ncompared with those of curcumin powder. The solid dispersion formulation effectively increased\nintestinal permeability and inhibited P-gp function. These effects increased the anti-proliferative\neffect of curcumin in MDA-MB-231 breast cancer cells. Moreover, 2 h incubation with curcumin\npowder, solid dispersion formulation, and its physical mixture resulted in differential cytotoxic effect\nof paclitaxel in P-gp overexpressed LLC-PK1-P-gp and MDA-MB-231 cells through the inhibition\nof P-gp-mediated paclitaxel efflux. In conclusion, compared with curcumin, a solid dispersion\nformulation of curcumin with TPGS and mannitol could be a promising option for enhancing\nthe oral bioavailability and efficacy of curcumin through increased solubility, dissolution rate,\ncell permeability, and P-gp modulation....
Chitosan-based nanogels have been widely applied as drug delivery vehicles. Spray-drying\nof said nanogels allows for the preparation of dry powder nano-embedded microparticles.\nIn this work, chitosan-based nanogels composed of chitosan, alginate, and/or sodium tri-penta\nphosphate were investigated, particularly with respect to the impact of composition on the resulting\nphysicochemical properties. Different compositions were obtained as nanogels with sizes ranging\nfrom 203 to 561 nm. The addition of alginate and exclusion of sodium tri-penta phosphate led to an\nincrease in nanogel size. The nanogels were subsequently spray-dried to form nano-embedded\nmicroparticles with trehalose or mannitol as matrix excipient. The microparticles of different\ncomposition were mostly spherical with a smooth surface and a mass median aerodynamic diameter\nof 6ââ?¬â??10 Ã?¼m. Superior redispersibility was observed for microparticles containing amorphous trehalose.\nThis study demonstrates the potential of nano-embedded microparticles for stabilization and delivery\nof nanogel-based delivery systems....
The aim of the present study was to study the efficiency of different techniques used\nfor nanosizing liposomes. Further, the aim was also to evaluate the effect of process parameters\nof extrusion techniques used for nanosizing liposomes on the size and size distribution of the\nresultant liposomes. To compare the efficiency of different nanosizing techniques, the following\ntechniques were used to nanosize the liposomes: extrusion, ultrasonication, freeze-thaw sonication\n(FTS), sonication and homogenization. The extrusion technique was found to be the most efficient,\nfollowed by FTS, ultrasonication, sonication and homogenization. The extruder used in the present\nstudy was fabricated using readily available and relatively inexpensive apparatus. Process parameters\nwere varied in extrusion technique to study their effect on the size and size distribution of extruded\nliposomes. The results obtained indicated that increase in the flow rate of the extrusion process\ndecreased the size of extruded liposomes however the size homogeneity was negatively impacted.\nFurthermore, the liposome size and distribution was found to decline with decreasing membrane\npore size. It was found that by extruding through a filter with a pore size of 0.2 �¼m and above,\nthe liposomes produced were smaller than the pore size, whereas, when they were extruded\nthrough a filter with a pore size of less than 0.2 �¼m the resultant liposomes were slightly bigger\nthan the nominal pore size. Besides that, increment of extrusion temperature above transition\ntemperature of the pro-liposome had no effect on the size and size distribution of the extruded\nliposomes. In conclusion, the extrusion technique was reproducible and effective among all the\nmethods evaluated. Furthermore, processing parameters used in extrusion technique would affect\nthe size and size distribution of liposomes. Therefore, the process parameters need to be optimized to\nobtain a desirable size range and homogeneity, reproducible for various in vivo applications....
The process variables and formulation variables poly caprolactone (PCL), poloxamer and poly vinyl alcoho (PVA) were investigated in the formulation of levodopa loaded nanoparticles. Preformulation studies were UV Spectrophotometer, FTIR spectroscopy (Fourier Transform Infra Red) and DSC (Differential Scanning Calorimetry). The purity of levodopa and interaction of levodopa with polymer and other excipients were studied using FTIR and no interactions observed. DSC studies revealed the presence of levodopa in the nanoparticles in amorphous form. Design of experiment was employed to evaluate the effect of formulation variables on the characteristics of nanoparticles. Nanoprecipitation and homogenization techniques were compared in the preparation of PCL nanoparticles. Prepared formulations were evaluated for particle size, entrapment efficiency surface morphology, surface charge, in-vitro drug release and the data obtained from in-vitro release studies were fitted to various release kinetic models such as zero order, first order, Higuchi, hixson-crowell, korsemeyer–peppas, baker and lonsdalel and weibull. Homogenization technique yielded nanoparticles with size ranging from 97.25 to 132.14 nm and higher entrapment efficiency upto 63.4%w/w while nanoprecipitation technique yielded nanoparticles with size range of 101.33 to 129.74 nm and entrapment efficiency upto 29.3 %w/w. The drug release also increased with homogenization technique. PVA was found to be a better stabilizer than poloxamer 407. Levodopa release decreased with increasing PCL amount. Formulation FP 8 contained 1:2 drug polymer ratio was coated with polysorbate 80. Stability studies indicated that there was no degradation of the drug in the formulation after 60 days of preparation when stored in refrigerated condition....
Citronella oil (CO) can be an effective mosquito repellent, but due to its nature which having high volatility,\noils rapidly evaporates causing loss of efficacy and shorten the repellent effect. Therefore, microencapsulation\ntechnology was implemented to ensure the encapsulated material being protected from immediate contact with\nenvironment and offers controlled release. In this study, microencapsulation of CO was done by employing complex\ncoacervation using chitosan-gelatin (B) system and utilized proanthocyanidins as the crosslinker. Remarkably, nearly\nall material involved in this study are from natural sources which are safe to human and environment. In designing\noperating process condition for CO encapsulation process, we found that wall ratio of 1:35 and pH 5 was the best\noperating condition based on zeta potential and turbidity analysis. FT-IR analysis found that gelatin-B had coated the\nCO droplet during emulsification stage, chitosan started to interact with gelatin-B to form a polyelectrolyte complex\nin adjust pH stage, CO capsules solidified at cooling process and were hardened during crosslinking process. Final\nproduct of CO capsules after settling process was identified at the top layer. Surface morphology of CO capsules\nobtained in this study were described having diameter varies from 81.63 m to 156.74 m with almost spherical in\nshape....
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