Disczrxsion: The frce-running SFDR of 84 dB/Hz'/' is thc highest rcported to date for frcc-running long wavelength VCSELs, which is further enhanced by injection locking. The rclatively high RlN valucs observed arc possibly due to reflections from the VCSEL-fibre coupling lenses [9], which is still under investigation. Rcducing the optical reflections is expected to reduce the RlN and further increase the SFDR.The enhancement in the fundamental power is attributed to the increase of photon density and possibly differcntial gain, which enhance the clectrical-optical modulation efficiency. Similarly, with the increase of photon density and differential gain, the rcsoiiaiicc frequency is increased. A larger offset bctwccii the modulation and resonance frequencies reduces thc nonlincar distortion enhanced by the carricr-photon interaction, which in turn rcduccs the third-harmonic , distortion. Concli~sion:We have demonstrated that iiijcction locking improves the analogue performance of long wavelength VCSELs. We have found that injection locking can improve the modulation bandwidth by a factor of two and reduce modulation nonlinearities. The gain of the VCSEL RF link was improved due to an increase in modulation efficiency. Finally, the third-harmonic spur-free dynamic range was improved by 9 ~B / H Z~/~ to be 93 dB/HzZi3. This is the highest rcported SFDR for a long wavelength VCSEL.

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Nanoparticles containing ibuprofen, indomethacin or propranolol were formed spontaneously after the addition of solutions of the drugs and acrylic polymers (Eudragit RS or RL 100) in the water-miscible solvents, acetone or ethanol, to water without sonication or microfluidization. The colloidal dispersions were stabilized by quaternary ammonium groups and did not require the addition of surfactants or polymeric stabilizers. The nanoparticles were compared to nanoparticles prepared either by a microfluidization-solvent evaporation method with a water-immiscible organic solvent, methylene chloride, or by a melt method with respect to particle size and redispersibility of freeze- or spray-dried samples. Nanoparticles prepared by microfluidization or the melt method were easily redispersed while Eudragit RS nanoparticles prepared by spontaneous emulsification were not redispersible. Flexible films were formed from the nanosuspensions after the addition of 15 per cent triethyl citrate, a water-soluble plasticizer. The release of propranolol from the films increased with increasing proportion of RL, but was independent of the order of mixing of the two polymers or nanosuspensions during film preparation. The drug release from indomethacin films was increased by adding water-soluble polymers to the nanosuspension.

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