A hydroxypropyl methylcellulose (HPMC K4M, HPMC K15M, and HPMC K100M) matrix tablet containing Indomethacin along with mannitol was formulated as a function of HPMC viscosity, and was compared with the commercial products. The release characteristics of the matrix tablet were investigated in the intestinal fluid, 6.8 pH phosphate buffer for 12 hours. The formulated products and two marketed products as reference sample were studied for its different physicochemical parameters and in vitro dissolution studies. It was found that the drug release profile decreases with increase in viscosity of polymer and, with increase polymer level in the formulations. Matrix tablets formulated employing Drug:HPMC K15M:mannitol::1:0.25:1 and Drug:HPMC K15M:mannitol::1:0.25:2 gave slow release of indomethacin spread over 12 hours and their dissolution profiles were compared with the Indian marketed product. The dissolution profiles of both the formulations were similar to the dissolution profile of the marketed product, the similarity factor being 74.59 and 68.04 respectively. The dissolution profiles of formulations containing same viscosity grade of HPMC in remarkably different concentrations and different viscosity grade of HPMC in same concentrations were different.

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A novel surface-attached, spray-dried solid dispersion containing poorly water-soluble carvedilol (CV) without any change in the crystallinity was prepared using water, polyvinylpyrrolidone (PVP K30) and Tween 80. The solid dispersion was optimized by investigating the effects of the weight ratios of Tween 80/PVP K30 and carrier/drug on the aqueous solubility of CV. The optimum solid dispersion consisted of a relatively low carrier to drug weight ratio: the weight ratio of CV/PVP K30/Tween 80 was 12/4/2. Unlike conventional methods of solid dispersion preparation, this method yielded CV-loaded solid dispersion with no change in the crystallinity of the drug as was evident from SEM, DSC and XRD. It was demonstrated that the solid dispersions prepared had hydrophilic carriers attached to the surface of the drug, thus changing it from a hydrophobic to a hydrophilic form without changing the crystalline form. The optimized solid dispersion improved the drug solubility and dissolution rate by about 11,500-fold and twofold, respectively. It was further suggested that this method of solid dispersion preparation is better than conventional methods in terms of environmental and industrial standpoints. Thus, it was concluded that CV-loaded solid dispersion prepared using this method would be of use for delivering poorly water-soluble CV with enhanced solubility and dissolution, but without crystalline changes.

A combined DoE approach enabled accurate optimization and successful preparation of IMT-NLC with enhanced in vivo pharmacokinetic and in vitro cytotoxicity characteristics.

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.

Please cite this article as: Roshan Pradhan, Sung Yub Kim, Chul Soon Yong, Jong Oh Kim, Preparation and characterization of spray-dried valsartan-loaded Eudragit ® E PO solid dispersion microparticles, Asian Journal of Pharmaceutical Sciences (2016), http://dx.doi.org/ ABSTRACTThe purpose of this study was to develop the immediate release stomach-specific spray-dried formulation of valsartan (VAL) using Eudragit ® E PO (EPO) as the carrier for the enhancing dissolution rate in a gastric environment. Enhanced solubility and dissolution in gastric pH was achieved by formulating the solid dispersion using a spray drying technique. Different combinations of drug-polymer-surfactant were dissolved in 10% ethanol solution and spraydried in order to obtain solid dispersion microparticles. Use of the VAL-EPO solid dispersion microparticles resulted in significant improvement of the dissolution rate of the drug at pH 1.2 and pH 4.0, compared to the free drug powder and the commercial product. A hard gelatin capsule was filled with the VAL-EPO solid dispersion powder prior to the dissolution test. The increased dissolution of VAL from solid dispersion microparticles in gastric pH was attributed to the effect of EPO and most importantly the transformation of crystalline drugs to amorphous solid dispersion powder, which was clearly shown by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and powder X-ray diffraction (P-XRD) studies. Thus, VAL, a potential antihypertensive drug in the form of a solid dispersion microparticulate powder can be effectively delivered in the immediate release dosage form for stomach-specific drug delivery.

The purpose of this study was to improve the gastric solubility and bioavailability of rebamipide (RBM) by preparing the RBM solid dispersion tablet (RBM-SDT) from solid dispersion powder prepared by spray-drying technique. For preparation of rebamipide solid dispersions (RBM-SDs), solubility study was performed in various hydrophilic carriers and alkalizers, among which sodium alginate and sodium carbonate were selected as the hydrophilic polymer and alkalizer, respectively. Different combinations of drug-polymer-alkalizer were dissolved in aqueous solution and spray-dried in order to obtain solid dispersions. Noticeable improvement in aqueous solubility (approximately 200 times) and in vitro dissolution rate was observed by RBM-SDs, compared to RBM powder. The optimized formulation of RBM-SD powder consisted of RBM powder/sodium alginate/sodium carbonate at the weight ratio of 1/2/2. The transformation of crystalline RBM to amorphous RBM-SD powder was clearly demonstrated by powder X-ray diffraction, differential scanning calorimetry (DSC) and scanning electron microscopy. The optimized RBM-SD was formulated in tablet dosage form, containing approximately 2 % sodium lauryl sulphate and poloxamer F68 as wetting agents. The RBM-SDT exhibited enhanced dissolution in hydrochloric acid buffer (pH 1.2) and distilled water. Moreover, pharmacokinetic study in rats showed higher AUC and Cmax for RBM-SDT than those for RBM powder and commercial product. Thus, the developed RBM-SDT formulation can be more efficacious for improving oral bioavailability of RBM.

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.