We studied the application of pulsed laser ablation (PLA) for particle size reduction in non-steroidal anti-inflammatory drugs (NSAIDs). Grinding of the poorly water-soluble NSAID crystallites can considerably increase their solubility and bioavailability, thereby the necessary doses can be reduced significantly. We used tablets of ibuprofen, niflumic acid and meloxicam as targets. Nanosecond laser pulses were applied at various wavelengths (KrF excimer laser, λ = 248 nm, FWHM = 18 ns and Nd:YAG laser, λ1 = 532 nm/λ2 = 1064 nm, FWHM = 6 ns) and at various fluences. FTIR and Raman spectra showed that the chemical compositions of the drugs had not changed during ablation at 532 nm and 1064 nm laser wavelengths. The size distribution of the ablated products was established using two types of particle size analyzers (SMPS and OPC) having complementary measuring ranges. The mean size of the drug crystallites decreased from the initial 30–80 µm to the submicron to nanometer range. For a better understanding of the ablation mechanism we made several investigations (SEM, Ellipsometry, Fast photography) and some model calculations. We have established that PLA offers a chemical-free and simple method for the size reduction of poorly water-soluble drugs and a possible new way for pharmaceutical drug preformulation for nasal administration.

Recently, the number of water insoluble and poorly soluble drug compounds has increased significantly. Therefore, growing interest has been witnessed in different particle size reduction techniques to improve the dissolution rates, transport characteristics and bioavailability of drugs. Laser ablation has proven to be an alternative method to the production of nano- and micrometre-sized drug particles without considerable chemical damage. We present the nanosecond laser ablation of drug pastilles in distilled water, targeting meloxicam, a poorly water soluble nonsteroidal anti-inflammatory drug, at different laser wavelengths (248 nm, 532 nm and 1064 nm). Besides chemical characterization, crystallinity, morphology and particle size studies, the mechanism of the particle generation process was examined. The applicability of ablated particles in drug formulation was investigated by solubility, cytotoxicity and anti-inflammatory effect measurements. We showed that laser ablation is a clean, efficient and chemically non-damaging method to reduce the size of meloxicam particles to the sub-micrometre–few micrometre size range, which is optimal for pulmonary drug delivery. Complemented by the excellent solubility (four to nine times higher) and anti-inflammatory (four to five times better) properties of the particles compared to the initial drug, laser ablation is predicted to have wider applications in the development of drug formulations.

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We investigated the application of pulsed laser ablation (PLA) for the production of magnetic nanoparticles (MNPs)/drug nanocomposites. Magnetic drug delivery vehicles can provide a multifunctional theranostic platform and allow for a combination of diagnostics, monitoring and therapeutics. We applied nanosecond laser pulses at two different wavelengths (Nd:YAG laser, λ 1 = 532 nm/λ 2 = 1064 nm, FWHM = 6 ns) for the ablation of target tablets consisting of a mixture of ibuprofen (as a model drug) and magnetite NPs in various mass ratios. Fourier-transform infrared and Raman spectroscopy investigations of the ablated particles revealed that PLA induced no chemical changes in the pharmaceutical compound. The size distributions of the composite particles were established using a particle size analyzer (scanning mobility particle sizer), and 100-150 nm mean particle size values were obtained. SEM, energy dispersive x-ray spectroscopy and fast photography studies provided morphological and compositional information about the ablated particles. We demonstrated that PLA offers a simple and chemical free method for producing MNPs/drug nanocomposites, and it can be applied for the future development of new theranostic nanosystems.

Nanoparticles of high purity can be produced from a variety of materials by pulsed laser ablation of solids in liquid. Composite nanoparticles are of great importance in various applications such as catalysis or biomedicine and the process of their formation is still a subject of intense research. In this work, gold/silver composite nanoparticles were synthesized in aqueous media by ns pulsed laser ablation of gold-silver multilayer targets with different absolute layer thicknesses and layer thickness ratios. The generated nanoparticles showed a log-normal distribution of sizes, with average diameter in the 20-40 nm range and standard deviation of 9-30 nm. By comparing the UV-VIS absorbance spectra of the nanoparticle colloids with two theoretical calculations (based on the Mie and the BEM model), it was found that there is a direct correlation between the average Au and Ag content of the nanoparticles and the composition of the films on the substrate. Assuming thermal ablation, our model calculations showed that there is a maximum thickness of the top layer up to which both layers can be ablated simultaneously and alloy nanoparticles can be produced.