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The objectives of this study were to develop and evaluate a novel self-emulsifying floating drug delivery system (SEFDDS)
that resulted in improved solubility, dissolution, and controlled release of the poorly water-soluble tetrahydrocurcumin (THC).
The formulations of liquid self-emulsifying drug delivery system (SEDDS; mixtures of Labrasol, Cremophor EL, Capryol 90, Labrafac
PG) were optimized by solubility assay and pseudo-ternary phase diagram analysis. The liquid SEDDS was mixed with adsorbent
(silicon dioxide), glyceryl behenate, pregelatinized starch, sodium starch glycolate, and microcrystalline cellulose and transformed
into pellets by the extrusion/spheronization technique. The resulting pellets with 22% liquid SEDDS had a uniform size and
good self-emulsification property. The microemulsions in aqueous media of different self-emulsifying floating pellet formulations
were in a particle size range of 25.9–32.5 nm. Use of different weight proportions of glyceryl behenate and sodium starch
glycolate in pellet formulations had different effects on the floating abilities and in vitro drug release. The optimum formulation (F2) had a floating efficiency of 93% at 6 h and provided a controlled release of THC
over an 8-h period. The release rate and extent of release of THC liquid SEDDS (80% within 2 h) and self-emulsifying floating
pellet formulation (80% within 8 h) were significantly higher than that of unformulated THC (only 30% within 8 h). The pellet
formulation was stable under intermediate and accelerated storage conditions for up to 6 months. Controlled release from this
novel SEFDDS can be a useful alternative for the strategic development of oral solid lipid-based formulations. 相似文献
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Amornrat Chumthong Mana Kanjanamaneesathian Ashara Pengnoo Ruedeekorn Wiwattanapatapee 《World journal of microbiology & biotechnology》2008,24(11):2499-2507
Endospores of B. megaterium were formulated in granule formulations with sodium alginate, lactose and polyvinylpyrrolidone (PVP K-30) by the wet granulation
technique. The granule formulation exhibited good physical characteristics, such as high-water solubility and optimal viscosity,
that would be suitable for spray application. The bacteria remained viable in the dry granule formulation at 109 c.f.u./g after 24 months storage at room temperature. Under laboratory conditions, aqueous solutions of the formulation showed
high activity against mycelial growth of R. solani (99.64 ± 0.14% mycelial inhibition). High viability of the bacterial antagonist on leaf sheath and leaf blade at day 7 after
spraying with the formulation was observed (approximately 106 c.f.u./g of plant). Application of an equivalent number of un-formulated endospores resulted in much loss of the bacterial
endospores even 1 day after application. In a small pilot field study, an aqueous solution of the formulation (3%w/v) applied
by spraying at days 1, 5 and 10 after pathogen inoculation of the rice plants was more effective in suppressing rice sheath
blight disease than one application of a fungicide (Iprodione) at day 1. Additionally, rice plants sprayed with the aqueous
solution of the granule formulation had higher panicle and whole kernel weights than those of fungicide-treated and control
(untreated) plants. 相似文献
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Ashara Pengnoo Ruedeekorn Wiwattanapattapee Amornrat Chumthong Mana Kanjanamaneesathian 《World journal of microbiology & biotechnology》2006,22(1):9-14
Summay Soil samples were taken from 48 fields in the southern part of Thailand in which either bambara groundnut (Vigna subterranea) or groundnut (Arachis hypogeae) had been planted. Bacillus spp. were isolated using soil dilution plates and heat treatment to screen for endospore-producing bacteria. Among 342 Bacillus spp. isolates tested, 168 isolates were not antagonistic to Bradyrhizobium sp. strain NC-92 using dual culture technique. Further testing found 16 isolates of Bacillus spp. had the ability to inhibit mycelial growth of Rhizoctonia solani, a causal agent of leaf blight of bambara groundnut. Among these isolates, Bacillus spp. isolate TRV 9-5-2 had the greatest activity in anti-microbial tests against R. solani. This isolate was later identified as B. firmus. A powder formulation of B. firmus was developed by mixing bacterial endospores, talcum, sodium carboxymethylcellulose (SCMC) and polyvinylpyrolidone (PVP).
The formulations contained bacterial levels ranging from 108 to 1010 c.f.u./g and the viability of bacteria in all formulations remained high after 1 year storage at room temperature (26–32 °C).
All formulations showed satisfactory effectiveness in vitro in suppressing mycelial growth of R. solani using dual culture technique. The application of formulations as seed treatment showed that these formulations did not cause
abnormality of seedling shape and had no effect on the germination of bambara groundnut seeds. 相似文献
4.
Namfa Sermkaew Kamonthip Wiwattanawongsa Wichan Ketjinda Ruedeekorn Wiwattanapatapee 《AAPS PharmSciTech》2013,14(1):321-331
Novel self-microemulsifying floating tablets were developed to enhance the dissolution and oral absorption of the poorly water-soluble tetrahydrocurcumin (THC). Their physicochemical properties and THC permeability across Caco-2 cell monolayers were assessed. The self-microemulsifying liquid containing THC was adsorbed onto colloidal silicon dioxide, mixed with HPMC, gas-generating agents (sodium bicarbonate and tartaric acid), lactose and silicified-microcrystalline cellulose and transformed into tablets by direct compression. The use of different types/concentrations of HPMC and sodium bicarbonate in tablet formulations had different effects on the floating characteristics and in vitro THC release. The optimum tablet formulation (F2) provided a short floating lag time (∼23 s) together with a prolonged buoyancy (>12 h). About 72% of THC was released in 12 h with an emulsion droplet size in aqueous media of 33.9 ± 1.0 nm while that of a self-microemulsifying liquid was 29.9 ± 0.3 nm. The tablet formulation was stable under intermediate and accelerated storage conditions for up to 6 months. The THC released from the self-microemulsifying liquid and tablet formulations provided an approximately three- to fivefold greater permeability across the Caco-2 cell monolayers than the unformulated THC and indicated an enhanced absorption of THC by the formulations. The self-microemulsifying floating tablet could provide a dosage form with the potential to improve the oral bioavailability of THC and other hydrophobic compounds.KEY WORDS: Caco-2 cells, controlled release, permeability, self-microemulsifying floating tablets, tetrahydrocurcumin 相似文献
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R. Wiwattanapatapee A. Chumthong A. Pengnoo M. Kanjanamaneesathian 《World journal of microbiology & biotechnology》2013,29(8):1487-1497
Bacillus megaterium encapsulated in calcium alginate microcapsules was prepared and tested for its efficacy against sheath blight disease of rice. In laboratory conditions, the aqueous suspension (1:100, v/v in potato dextrose agar) of the bacterial microcapsules (1010 spores/ml) inhibited mycelial growth of Rhizoctonia solani (>99 %) after the microcapsules were produced and stored for 12 months at room temperature (28 ± 2 °C). The survival of the bacterium in the microcapsules in response to ultraviolet (u.v.) irradiation and high temperature was investigated. The survivability of the bacterium in the encapsulated form was greater than that of the fresh cells when it was subjected to u.v. (20-W General electric u.v. lamp from a 25 cm distance for 48 h) and a high temperature treatment (80 °C for 48 h). Cells of the bacterium were detected by scanning electron microscope on both the leaf sheath and the leaf blade (in pot tests in a greenhouse) after spraying encapsulated product. The number of bacteria on the surface of both rice tissues (5 Log. number/g of plant) after spraying with encapsulated product was not significantly different from that after spraying with fresh cells onto the rice seedlings. Spraying the encapsulated B. megaterium on rice plants in the greenhouse was as effective as spraying a chemical fungicide for suppressing rice sheath blight disease. 相似文献
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