Design, Preparation, and Mechanical Property Study of Polylactic Acid/Ca2BO3Cl: Eu2+, Dy3+ Composite Material for 3D Printing.

To break through the simplification of three-dimensional printing (3DP) materials and realize the application of long-persistent phosphors in more fields, polylactic acid doped with Ca2BO3Cl: Eu2+, Dy3+ was prepared in this study. The structure of the mixtures was analyzed and determined by infrared spectroscopy. The luminescence properties of phosphors and the composites were studied by fluorescence spectra and afterglow decay curve measurements. The yellow light of the mixtures could be attributed to the 5d-4f energy level transition of Eu2+. After the excitation of 254 nm ultraviolet lamp, the luminance and duration of the composites could be clearly observed. The mechanical properties of the composite filaments were tested, including maximal force and elasticity modulus. In particular, the influence of humidity on mechanical properties was analyzed in detail. The prepared composite filaments were printed into hollow dodecahedrons and presented in this study. Therefore, the composites had great properties and might be expected to put into practical applications of 3DP technology.

[Continuous in situ monitoring of the dissolution rate of solid pharmaceutical preparations using a multiple channel fiber-optic chemical sensor].

AIM: To study the dissolution rate of solid pharmaceutical preparation on-line, a multiple channel fiber-optic chemical sensor based on fluorescence multiple quenching (FOCSMQ) without filtering and sampling was made. METHODS: Using the multiple channel FOCSMQ linked with computer, the dissolution rates of ofloxacin tablets, metronidazole tablets and nitrofurantoin tablets were monitored continuously on-line. The instrument can give the sample data, display the real time curve and calculate the T1/2 and td automatically. A computer was used to select the best function from five common fitting models to fit the dissolution curve. RESULTS: The average recoveries of the FOCSMQ method were 97.4%-104.4%, 97.4%-103.8% and 96.6%-102.1%. The RSDs (n = 6) of within-day and between-day were less than 5%. The parameters of the dissolution and all results of measurement using the instrument have no significant difference compared with the Chinese Pharmacopoeia (ChP) (2000) method and the United States Pharmacopoeia (USP) (23) method (P > 0.05). It does not need sampling and dilution, and never contaminate sample. It can shorten time of the experiment. CONCLUSION: The method is simple, rapid and reliable.