Formulation development and toxicity assessment of triacetin mediated nanoemulsions as novel delivery systems for rapamycin

The aim of this investigation was to design and develop nanoemulsions [NEs] as novel delivery systems for rapamycin. Phase behavior of quaternary systems composed of Traicetin [as oil], various surfactants and co-surfactants and water at different surfactant/co-surfactant weight ratios was investigated by the construction of phase diagrams. Formulations were taken from the o/w NE region of the phase diagrams, depending upon the extent of NE domain. The spontaneous emulsification method was used to prepare various formulations containing 1 mg/mL of the drug. The NEs were characterized and subjected to stability tests at various temperatures over 9-12 months. Cumulative drug release from the selected formulations was determined for a period of 48 h using a dialysis sac. The assay of rapamycin was carried out using an HPLC technique. The effect of NEs on the viability of SKBR-3 cells was evaluated by MTT assay. The integrity of Caco-2 cell monolayers was measured by Transepithelial Electrical Resistance [TEER] and the transport of rapamycin-loaded NEs across Caco-2 cell monolayers was then assessed. The uptake of NEs by SKBR-3 cells was also investigated using florescence microscopy. Maximum drug release was observed in case of 4 formulations prepared with Tween 80 and Tween 20. MTT test results revealed different toxicity of NEs for SKBR-3 cell line and TEER demonstrated that formulations containing Tween 20 caused a more considerable decrease in cell integrity in comparison with those prepared with Tween 80. The results obtained from cellular uptake experiments were in consistent with those obtained from TEER and cytotoxicity experiments

Simultaneous determination of triacetin, acetic ether, butyl acetate and amorolfine hydrochloride in amorolfine liniment by HPLC

A simple, rapid, specific and precise reversed-phase high-performance liquid chromatographic method was developed for simultaneous estimation of triacetin, acetic ether, butyl acetate and amorolfine in marketed pharmaceutical liniment. Chromatographic separation was performed on a Shimadzu VP-ODS C18 column using the mixture of citric acid-hydrochloric acid-sodium hydrate buffer [pH 3.0], acetonitrile and methanol [32:30:38] as the mobile phase at a flow rate of 1.0 mL/min with UV-detection at 215 nm. The method separated the four components simultaneously in less than 10 min. The validation of the method was performed with respect to specificity, linearity, accuracy, and precision. The calibration curves were linear in the range of 35.1-81.9 micro g/mL for triacetin, 431.1-1005.9 micro g/mL for acetic ether, 167.0-389.7 micro g/mL for butyl acetate and 151.0-352.3 micro g/mL for amorolfine. The mean 100% spiked recovery for triacetin, acetic ether, butyl acetate and amorolfine is 99.43 +/- 0.42, 101.5 +/- 1.09, 101.4 +/- 1.02 and 100.8 +/- 0.69, respectively. The intra-day and inter-day relative standard deviation values were <2.0%. The limits of detection of these compounds ranged from 0.08 to 5.88 ng. The utility of the procedure was verified by its application to the commercial liniment

The mechanical properties and moisture permeability of eudragit L100/S100 free films affected by plasticizers and membrane materials ratio / 药学学报

The free membrane of Eudragit L100/S100 which is pH-sensitive, colon-specific was prepared by plane casting films. The film humidity, species and amount of plasticizers, the ratio of membrane material was investigated. The rate of membrane permeability and mechanical properties were used as indicators of orthogonal experiment, and its related properties were studied. The results show that the mechanical properties of the membrane and phragmoid capacity are the best when 30% TEC was used as plasticizer; the ratio of membrane material have little effect on the rate of membrane permeability and mechanical properties. By adjusting the species and amount of plasticizers, the ratio of Eudragit L100/S100, the free membrane which is colon-specific can be obtained.