ABSTRACT
There has been increasing interest in research and development of nanocrystals for the delivery of poorly water-soluble drugs that can be directly produced from solution. Compared with traditional carrier-based or encapsulation designs, drug nanocrystals circumvent possible side-effects due to carrier polymers and poor stability issues associated with encapsulation. The production of carrier-free nanocrystals requires careful control of nucleation and thus a thorough understanding of the relevant solution's metastable zone. A solution may stay supersaturated without forming any nuclei and become metastable. The maximal degree of supersaturation is known as the metastable zone width. When nucleation is triggered directly from the metastable zone, it helps to produce homogeneous nuclei leading to uniform nanocrystals. Herein, we report a study in which the solubility and metastable limit of paclitaxel (PTX) in ethanol aqueous solution were measured at 40 °C. A wide range of metastable compositions were studied to prepare carrier-free PTX nanocrystals with particle size smaller than 250 nm and PDI less than 0.25. Compared with the raw material, dissolution rate of PTX nanocrystals was significantly increased. The study enables production of high-quality drug nanocrystals for treating patients.
ABSTRACT
Objective To prepare methoxy polyethylene glycol (mPEG)-polycaprolactone (PCL) nanoparticles loading a water-quenching fluorescent probe and to evaluate its in vitro characteristics and stability.Methods PCL nanoparticles and mPEG-PCL nanoparticles with different mPEG chain lengths (mPEG5k,mPEG2k) loading the waterquenching fluorescent probe P2 were prepared by an emulsification/solvent evaporation method using PCL and mPEG-PCL as materials.In vitro characteristics such as morphology,particle size and distribution were evaluated.The P2 probe displayed fluorescent signals when encapsulated in the matrix of the nanoparticles,but quenched immediately when released into water.Based on this properties of P2 probe,the stability of various nanoparticles in different aqueous media was investigated.Results The prepared mPEG-PCL nanoparticles showed a particle size of about 200 nm,narrow size distribution,polydispersity index below 0.06 and near neutral surface potentials with spherical morphology and smooth surfaces.In buffers of different pHs and simulated bio-relevant media,all nanoparticles showed very good stability without significant change in particle size,polydispersity index and fluorescence intensity.Conclusion mPEG-PCL nanoparticles have promising in vitro characteristics and robust stability.It is fast and convenient to monitor the stability of nanoparticles by using the water-quenching probe.
ABSTRACT
The aerosol of biodegradable multi-function film was prepared by means of two-step methods, and its properties were investigated. The average loading capacity was 4.8603 g; the average leaking rate was 3.03% per year which was less than 5%. And the average ejecting rate was 0.7380 g/s. The results demonstrate that the aerosol of biodegradable multi-function film has met the principles governing the quality of the aerosols.
Subject(s)
Aerosols , Biocompatible Materials , Biodegradation, Environmental , Biomechanical Phenomena , Lactic Acid , Chemistry , Materials Testing , Membranes, Artificial , Polyesters , Polyglycolic Acid , Chemistry , Polymers , ChemistryABSTRACT
OBJECTIVE:To prepare nattokinase immunoliposomes and its lyophilized product and to evaluate its pharmaceutical quality. METHODS: Nattokinse liposomes were prepared by film dispersion method, then the immunoliposomes were prepared by carbodiimide method coupled anti-human fibrin D-dimer monoclone antibody SZ-63 and lyophilized and evaluated about its pharmaceutical quality. RESULTS: Lyophilized immunoliposomes were multilamellar vesicles with its mean diameter, Zeta potentials at 251.6 nm, —34.6 mV, respectively. The lyophilized product of nattokinase immunoliposomes exhibited good appearance and satisfactory redispersibility, with its loss on drying at 14.30% and critical relative humidity at 45.66%. CONCLUSION: Nattokinase immunoliposomes and its lyophilized product have been prepared successfully.