Kuhnil Pharma Co., Ltd.

A new triglyceride-free propofol microemulsion for intravenous injection was formulated using nonionic surfactants, poloxamers and polyethylene glycol 660 hydroxystearate. The aim of this investigation was to evaluate the formulation for storage stability, antimicrobial activity, toxicity and preclinical efficacy. The results were compared to the characteristics obtained for the most commonly used formulation of propofol (Diprivan®). The mean particle diameter of the microemulsion was less than 100 nm so that it could be readily sterilized using a 0.22 μm membrane at room temperature. The microemulsion formulation demonstrated enhanced stability compared to the marketed macroemulsion formulation. In a stress storage condition, it was physicochemically stable for at least 40 months. This new formulation showed higher antimicrobial activity, lower risk of hyperlipidemia and better tolerability than Diprivan®. In preclinical studies, the efficacy and pharmacokinetic profile of the microemulsion were similar to those of Diprivan®. Nevertheless, the administration of the microemulsion caused considerably low histamine release compared to the macroemulsion. Based on these results, the newly developed microemulsion of propofol appeared to have several advantages and, thus, could be an alternative to the fat macroemulsions of propofol.

Docetaxel-loaded liposomes were prepared by emulsion-solvent evaporation method, then coated with chitosan at room temperature and lyophilized. This system was designed in order to improve solubility and stability of docetaxel in the GI tract for oral drug delivery. The solubilizing effect of some frequently used solubilizers and/or liposome was determined Among the results docetaxel-loaded liposomes prepared with 0.5% TPGS as a solubilizer showed 100-fold higher solubility than docetaxel. In a stability test, mean particle size of different liposome formulations was measured by a particle size analyzer in simulated gastric fluid (SGF) and in simulated intestinal fluid (SIF). The particle size of uncoated liposomes was significantly increased compared with that of chitosan-coated liposomes in SGF, however, there was no significant difference between coated and uncoated liposome in SIF. It is evident that chitosan-coated liposomes were more stable in GI conditions. The release characteristics of docetaxel-loaded liposomes were also investigated in three buffer solutions (pH 1.2, 4.0, 6.8). Docetaxel release did not occur in pH 1.2 for 4 h. However, in pH 4.0 and 6.8 conditions, docetaxel was gradually released over 24 h as a sustained release. It seems that aggregation and precipitation of particles by electrostatic interaction might protect docetaxel from being released. In Conclusion, the results from this study show that the chitosan-coated liposomes may be useful in enhancing solubility and GI stability of docetaxel.

A gastro-retentive(GR) dosage form of gabapentin was developed and its dissolution characteristics were evaluated. GR tablet consists of expandable core tablet matrix and semi-permeable membrane coating. Poloxamer 407 and sodium bicarbonate were used to prepare the core matrix. Polyvinyl acetate dispersion (Kollicoat SR30D) and polyvinyl alc.-polyethylene glycol copolymer (Kollicoat IR) were employed to form the semi-permeable membrane. The GR tablets significantly expanded up to fivefold in simulated gastrointestinal fluids with no apparent damage of the coating membrane over 12 h. Also, the swelling rate was controllable with the amount of sodium bicarbonate. The drug release was observed to be substantially sustained based on coating level. The release rate of gabapentin from the GR tablet was gradually slowed down as the coasting amount was increased. The gabapentin GR tablet with 8% coating level showed a pseudo-zero order release kinetics over 12 h. Thus, swellable GR tablet system having semi-permeable membrane coating can be applicable for hydrophilic drug substances like gabapentin.