ABSTRACT
The present study deals with characterization of dispersions of a poorly water-soluble drug, celecoxib [CLX] in polyvinyl caprolactame-polyvinyl acetate-polyethylene glycol graft copolymer [Soluplus[R] [SOL]] prepared by different techniques. Dispersions of CLX in SOL at different ratios [2:1, 1:1, 1:2, 1:4 and 1:6] were prepared by spray drying, conventional solvent evaporation and melting methods. The solid states of samples were characterized using particle size measurements, optical and scanning electron microscopy, XRPD, DSC and FT-IR. The Gordon-Taylor equation was used to predict the T[g] of samples and the possibility of interaction between CLX and SOL. The solubility and dissolution rate of all samples were determined. Stability of samples was studied at ambient conditions for a period of 12 months. DSC and XRPD analyses confirmed amorphous state of drug in samples. Surprisingly dispersions of CLX:SOL with the ratio of 2:1 and 1:1 showed slower dissolution rate than CLX while other samples showed higher dissolution rate. At 1:2 ratio the spray dried samples exhibited higher dissolution rate than corresponding samples prepared by other methods. However at higher SOL content [1:4 and 1:6], samples prepared by different methods showed similar dissolution profiles. The stability studies showed that there were no remarkable changes in the dissolution profiles and solid state of the drug after 12 months storage at ambient conditions. It was concluded that SOL was a proper carrier to enhance the dissolution rate of CLX. At high SOL ratios the method of preparation of dispersed samples had no effect on dissolution rate, whilst at low SOL content spray drying was more efficient method
Subject(s)
Sulfonamides , Polyethylene Glycols , PolyvinylsABSTRACT
To evaluate the influences of aqueous extracts of plant parts [stem, leaves, and root] of Portulaca oleracea L. on bioformation of silver nanoparticles [AgNPs]. Synthesis of silver nanoparticles by different plant part extracts of Portulaca oleracea L. was carried out and formation of nanoparticles were confirmed and evaluated using UV-Visible spectroscopy and AFM. The plant extracts exposed with silver nitrate showed gradual change in color of the extract from yellow to dark brown. Different silver nanoperticles were formed using extracts of different plant parts. It seems that the plant parts differ in their ability to act as a reducing and capping agent
Subject(s)
Silver , Nanoparticles , Plant ExtractsABSTRACT
Myeloperoxidase [MPO] and paraoxonase-1 [PON1] are inflammatory and anti-inflammatory enzymes, respectively that have been involved in the pathogenesis of coronary artery disease [CAD]. In this study we sought to evaluate the relations of MPO and PON1 with high density lipoprotein [HDL] mean size in patients with acute coronary syndrome [ACS]. Collectively, 50 control subjects and 50 patients with ACS were participated in this study. MPO level and PON1 activity was determined using immunoassay and colorimetric methods, respectively. HDL mean size was determined by a dynamic light scattering methodology. Other clinical risk factors were also determined by standard methods. The MPO/PON1 ratio amount was significantly higher in patients with ACS [1.49 +/- 1.10] than in control subjects [0.21 +/- 0.14] [P<0.01]. There was a significant correlation between MPO/PON1 ratio and HDL mean size in patients with ACS. Amount of the enzymes and their relations to HDL particle size in patients with ACS may play a part in the pathogenesis of ACS. Also, MPO/PON1 ratio may be a robust predictor of ACS
ABSTRACT
The main objective of this study was to prepare colon-specific pellets of budesonide, using pectin as film coating. Pellet cores of budesonide were prepared by extrusion / spheronization technique. Pectin, in different ratios was combined with Eudragit RS30D, Eudragit NE30D or Surelease to produce film coating. The dissolution profiles of pectin coated pellets were investigated in pH of 1.2 [2 h], pH of 7.4 [4 h] and pH of 6.8 in the absence as well as presence of rat cecal contents [18 h]. Finally the selected formulation was evaluated on trinitrobenzenesulfonic acid [TNBS] induced ulcerative colitis in rat model, in comparison with conventional UC treatments. The dissolution profiles of pectin coated pellets showed that the release of budesonide in presence of rat cecal content depended on adjuvant polymer, the ratio of pectin to polymer and film thickness. Coated pellets, prepared out of pectin and Surelease at a ratio of 1:3 at coating level of 35% [w/w], could increase budesonide release statistically in presence of rat cecal content, while they released no drug in pH of 1.2 and 7.4. Animal experiments revealed the therapeutic efficacy of pectin/Surelease-coated pellets of budesonide in alleviating the conditions of TNBS-induced colitis model as reflected by weight gain, as well as improvement of clinical, macroscopic and microscopic parameters of induced colitis. This confirmed the ability of the optimized formulation for targeted drug delivery of budesonide to colon