Non-degredation Nanonization Of Insoluble Drugs By High Repetition Femtosecond Laser

Femtosecond laser micromachining has been widely used in many fields, but thetraditional use of femtosecond laser micromachining mostly generated by the lowrepetition rate femtosecond Ti-sapphire light source, thus limiting its processingefficiency and speed. By means of various nano method, Class II (non-soluble drugbut can be absorbed)drugs’ biological activity can be improved. And it means suchdrugs can be used in actual clinical application. Among all methods, femtosecondlaser can produce stable and clean nano-drug particles. In this thesis, we use a highrepetition rate (50MHz) femtosecond laser to process:1, nanorization of insolubledrugs paclitaxel in aqueous, processing paclitaxel from micron particles intonanoscale,500nm average.2, nanorization of the insoluble drugs betamethasonedipropionate, from one hundred micrometers of betamethasone dipropionate intoparticles of1-10micron particles. The spectrum analysis after the experimentconfirmed the use of high repetition rate femtosecond laser generated no newsubstances in the process and shown hardly any degradation. This thesis for the firsttime proved that high repetition rate femtosecond laser with moderate pulse energyhave more advantages in nano-pharmaceutical field than conventional nanosecondlasers or high repetition rate femtosecond laser with low pulse energy, and for thefirst time introduce Non-thermal melting theory.Thesis is divided into the following sections:1, Describes the previous research progress and the general theory offemtosecond laser processing of high repetition rate femtosecond laser processing, aswell as drug nanonization common requirements methods, and the previous results ofthe water-based nano machining.2, Introduce the basic theory and experimental procedures used in photoniccrystalfiber laser, high performance liquid chromatography, scanning electronmicroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, massspectrometryanalysis and various testing instruments.3, Nanorization of paclitaxel and betamethasone dipropionate two kinds ofmedicines by the photonic crystal fiber femtosecond laser processing.4, Testing the purity and medical activity of the two drugs before and afterprocessing. Experiments confirmed the high repetition rate femtosecond lasers mayintroduce hardly any degradation to the medicines and maintain the molecular structure. Nano machining by laser without degradation is first discovered.5, Discuss the ultraviolet spectrum of two drugs by Gaussian linear regressionanalysis. Our high rate femtosecond laser machining thoety is different from plasma-wave theory which introduced by canadian years ago.Because four-photon absorptionopen molecular bonds led to electronic transition,which made the transfer of theelectron cloud. Finally the Non-thermal melting phenomenon brought about thegeneration of nano medicine particles.