Potential mucoadhesive dosage form of lidocaine hydrochloride: II. In vitro and in vivo evaluation

The aim of this study was to develop a controlled release buccal mucoadhesive delivery system for systemic delivery of lidocaine hydrochloride as a model drug. In vitro release and buccal permeation as well as in vivo permeation of LDHCL patches were evaluated. The drug release and the permeability of the drug through porcine buccal mucosa were evaluated using Franz diffusion cell. In vivo evaluation of patches was carried out on rabbits as an animal model. Patches were designed in two fashions, bi-layer (BLP; LDHCL, carbopol, glycerin, pentration enhancer, and Tween 20 as the first layer; and EVA as the second layer) and triple layer (TLP; LDHCL, carbopol and glycerin as the first layer; carbopol, glycerin, pentration enhancer and pluronic F-127 as the middle layer; and EVA as the third layer) patches, respectively. Presence of oleic acid as PE in the formulation significantly enhanced the in vitro permeability of LDHCL (p<0.05), while propylene glycol monolaurate as PE suppressed it (p<0.05). The in vivo evaluation in rabbits showed that TLP had significantly higher Cmax and AUC0-8 (p<0.05) than BLP. Furthermore, TLP showed a well-controlled drug plasma concentration over 6 hr which was significantly longer than BLP (p<0.05). Patches were well adhered to buccal mucosa of the rabbits over the 8-hr study period. It was postulated that the hypothetical release mechanism of the drug and oleic acid from TLP was controlled by their diffusion through the swollen polymer network and micelled gel.     

Microbiological and chemical quality of ground beef treated with sodium lactate and sodium chloride during refrigerated storage

The effects of sodium lactate (NaL) and sodium chloride (NaCl), either alone (30 g/kg) or in combination (20+20 g/kg), on the microbiological and chemical quality of raw ground beef during vacuum-packaged storage at 2°C were investigated. The results showed that addition of NaL alone or in combination with NaCl significantly delayed the proliferation of aerobic plate counts, psychrotrophic counts, lactic acid bacteria and Enterobacteriaceae and extended the shelf life of the product up to 15 and 21 days, respectively, versus 8 days only for control. Over the storage time (21 days), NaL maintained the ground beef at almost constant pH, while the pH of control or NaCl-treated samples significantly decreased. Lipid oxidation (TBA value) was not affected by addition of NaL. At storage day 21 however, TBA values of both NaL-treated (0.309) and control (0.318) samples were significantly lower than those of samples treated with NaCl (0.463). The combination of NaCl with NaL significantly reduced the oxidative changes caused by NaCl (0.384 versus 0.463). Therefore, NaL alone or in combination with NaCl could be utilized successfully to reduce the microbial growth, maintain the chemical quality, and extend the shelf life of ground beef during refrigerated storage.     

Novel combination of anionic and cationic polymethacrylate polymers for sustained release tablet preparation

The objectives of this study were to prepare and evaluate a novel sustained release tablet formulation using a binary mixture of polymethacrylate polymers: Eudragit E-100 (EE) and Eudragit L-100 (EL) in their salt forms. Tablets prepared using EE-citrate and EL-Na showed the highest degree of swelling among other combinations of EE and EL. The drug release rates were independent of the pH of the dissolution medium as the release profiles exhibited a continuous release pattern with no burst effect when changing the pH of the medium. These results, along with other test results, indicated the presence of an ionic interaction between both polymers when combined in the salt forms.