Anesthesia was supplemented by topical proparacaine HCl

reagents were of analytical grade. Preparation of the inserts Monolayer DIZE loaded inserts were prepared by using solvent/casting technique, according to previous studies. First, a solution containing 4 mg/mL of DIZE and 15 L/mL of acetic acid was prepared. Then, chitosan was added at the concentration of 20 mg/mL to obtain a viscous dispersion, which was magnetically stirred overnight to ensure homogeneity of both drug and polymer. The dispersion was casted, at room temperature, in circular silicone-molded trays containing individual 5 mm 2 mm wells. After casting, inserts were gently removed from the SMT and stored in recipients protected from light and air humidity. Placebo inserts were produced similarly, but changing the solution containing DIZE and acetic acid to another containing only acetic acid. Characterization of the inserts Swelling studies. Swelling studies of the inserts were carried out in a phosphate buffer solution pH 7.4. Each PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19748118 insert was weighed and placed in PBS for predetermined periods of time, as described by. After immersion, the inserts were removed from the medium, the excess surface water was eliminated by using filter paper and the inserts were weighed. The degree of swelling was calculated by using the following equation: Swelling index =, where the weight of the swollen insert after predetermined period of time is represented by Wt and the original weight of the insert at zero time is represented by W0. This experiment was performed in triplicate. Attenuated total reflectance Fourier transformer infrared MedChemExpress Seliciclib spectroscopy analysis. Attenuated total reflectance Fourier transformer infrared spectroscopy spectra were taken to confirm the chemical stability of DIZE after preparation of the inserts. ATR-FTIR spectra of DIZE inserts, placebo inserts and powdery DIZE were recorded on a Perkin Elmer FTIR spectrometer, Model Spectrum One. Spectra form 4000 to 600 cm-1 was recorded. Differential scanning calorimetry analysis. Differential scanning calorimetry measurements were carried out in a Shimadzu DSC50. Samples were packed in an aluminum crucible and heated at a rate of 10C/min. Nitrogen, at the rate of 20 mL/min, was used as a purge gas during the role analysis. The specimens were heated from -50C to 200C. Afterward, the specimens were cooled to -50C at the same rate of 10C/min and then they were reheated to 400C at a rate of 10C/min. Scanning electron microscopy analysis. The morphology of the inserts was evaluated using a JEOL scanning electron microscope, model JSM6360LV, operating at 15 kV. The samples were prepared by freezing the inserts in liquid nitrogen. After freezing, the inserts were fractured. Next, the surface and sides of the inserts were analyzed. The devices were analyzed at suitable acceleration voltages using varying magnification for each sample. Representative electron micrographs were also taken. Quantification of DIZE in inserts. The amount of DIZE in the inserts was quantified by UV/Vis spectroscopy. A Shimadzu ultraviolet spectrometer was used at a wavelength of 425 nm. The method was validated in accordance with ICH guidelines. The DIZE concentration ranged from 4.0 to 20 g/mL in 10% NaOH . In vitro drug release. In vitro drug release was evaluated using the Franz cell system . A cellulose acetate membrane with 0.45 PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19748686 m pores was used to split the insert compartment from the receptor liquid compartment. PBS was used as a receptor liquid and the glass cells were incubated at 37 0.5C. At app