ABSTRACT
Objective To establish and validate a LC-MS/MS method for quantitative analysis of a new anti-stroke compound TID-101 in rat plasma and to study the pharmacokinetics and bioavailability of TID-101 self-(micro)emulsified drug delivery system (SMEDDS). Methods The plasma samples were treated with methanol for precipitating protein. The chromatographic separation was achieved with a acetonitrile-water mobile phase. Detection of TID-101 and the internal standard (IS) dexamethasone acetate was achieved by electrospray ionization(ESI)source in the negative ion mode at m/z 353.4→323.2 and m/z 433.4→353.4. The method was applied for pharmacokinetics study of TID-101 between SMEDDS in rats. Results The method was linear over TID-101 concen?tration range from 10-95 000 ng/ml with the correlation coefficients(r)of 0.9998. The intra-run and inter-run relative standard devia?tions(RSD)were less than 15%and the average absolute recovery values were 83.4-87.0%. The validated method was applied to a pharmacokinetic study in rats after intravenous administration of TID-101 fat emulsion injection and oral administration of TID-101 suspension and SMEDDS. The bioavailability of TID-101 API and SMEDDS was 2.8% and 14.9%,respectively. Conclusion The analysis method is simple,accurate,and sensitive for assaying the in vivo pharmacokinetic study of TID-101 in rats. SMEDDS could effectively enhance the oral bioavailability of TID-101.
ABSTRACT
Nowadays, nanotechnologies have shown wide application foreground in the biomedical field of medicine laboratory tests, drug delivery, gene therapy and bioremediation. However, in recent years, nanomaterials have been labeled poisonous, because of the disputes and misunderstandings of mainstream views on their safety. Besides, for the barriers of technical issues in preparation like: (1) low efficacy (poor PK & PD and low drug loading), (2) high cost (irreproducibility and difficulty in scale up), little of that research has been successfully translated into commercial products. Currently, along with the new theory of "physical damage is the origin of nanotoxicity", biodegradability and biocompatibility of nanomaterials are listed as the basic principle of safe application of nanomaterials. Combining scientific design based on molecular level with precision control of process engineering will provide a new strategy to overcome the core technical challenges. New turning point of translational medicine in nanotechnology may emerge.
ABSTRACT
Despite tre mendous research efforts have been devoted to the analysis of nanoparticles (NPs)biohazard,the potential mechanism for nanotoxicity has not yet been syste mati-cal y elucidated.This review intends to point out the confusions about nanotoxicity in the field and tries to look into the mecha-nism from a new perspective.Currently,there are three puzzles:① no relationship between dose and toxicity could be observed in nanotoxicity;②there is a theory for the″size effects″,however, it cannot explain some cases contrary to the doctrine;③ NPs made of different materials with various sizes could have the same toxic effects through sti mulating oxidative stress.In fact, human body is co mposed of various biological molecules,and the biological function of a living syste m is reflected by the inter-actions and conversions of those molecules.NPs,on the other hand,are the invader of human body which has no ability to transport or convert or digest the foreigner.Thus,NPs could cause celldamage due to the physical blockage of micro-circula-tion,celldestruction due to membrane rando m insertion,and celldysfunction due to physical contacting with big biological mole-cules.The physical damages caused by various NPs could be divided into three categories:adhesion lesion,card inlay and puncture.Above al ,by analyzing wide spectrum of NPs varying in co mposition,shape and size,the author draws a conclusion that physical damage is the origin of nanotoxicity.