Application of solvent evaporation technique for pure drug crystal spheres preparation

An innovative application ofthe solventevaporation technique was suggested.Solventevaporation tech nique is a technique for drug encapsulation and nanosphere preparation.The widely used technique is also facing the problem of low actual drug entrapment percent,which is not economic from the industrial view.The goal of this work is trying to use the advantage of this technique concerning the product sphericity and the ability to control particle size,to prepare a drug as pure crystals spheres.Ibuprofen is selected as a model drug.The spheres are formed by using Polyvinyl pyrrolidone(PVP)or Polyethylene glycol(PEG)as an anti-aggregating agent but not formed on using tween or span.Particle size and actual drug content depend on the concentrations the anti-aggregating agent used.Surfaces of the drug crystal spheres are porous with empty sphere internal structure on using PvP but spongy and rough on using PEG.The drug has its identity chemical form in the drug crystal spheres.IR scan of spheres prepared on using PEG showed a characteristic ether peak.DSC showed melting endothermic peak of PEG,but X-ray showed minor change in the drug crystal patterns.Drug release profiles from crystal spheres prepared with the same anti-aggregating agent are close to each other.The drug release profiles from drug crystal spheres prepared by using PEG are more controlled than that prepared by using PVP.The drug release mechanism is diffusion.It was concluded that,the same technique could be suggested for preparation ofother biomedical material in pure crystals spheres with controlled particle size.These properties may encourage to prepare very small particles with spherical shape for inhalation or injection as an innovative particle technology application for the widely used technique.

Preparation and characterization of biomimetic adsorbent from poly-3-hydroxybutyrate

Biomimetic adsorbent named as PHBBMA was prepared from lipophilic poly-3-hydroxybutyrate （PHB） by a modified double emulsion solvent evaporation method. PHBBMA, characterized by using scanning electron microscope and nitrogen adsorption/desorption measurements, is porous spherical particles. The characterization with the thermal gravimetric analysis and differential scanning calorimetry, 1 H nuclear magnetic resonance and Fourier transform infrared spectroscopy showed that PHBBMA preparation was a physical process without chemical reaction. The adsorption of PHBBMA for o-nitrochlorobenzene （o-NCB） was fitted better by Langmuir model than by Freundlich model, while the pseudo second-order model fitting was better than the pseudo first-order model fitting. The maximal adsorption capacity of PHBBMA for o-NCB was 57.83 mg/g at 30°C, although its specific surface area （S BET ） was only 8.45 m 2 /g. PHBBMA is a safe and environmental friendly adsorbent with high adsorption capacity because its component is innocuous and biodegradable PHB produced reusing wastes and contaminants, no byproduct can produced, and its ester and hydrocarbyl groups have strong affinity with organochlorine compounds. The further work will focus on the modification and improvement of PHBBMA in order to increase its S BET and adsorption capacity.

Optimization of Jiawei Qing'e Oral Fast Disintegrating Tablets Based on Response Surface-Central Composite Design

Abstract: Objective To apply the response surface-central composite design to developing and optimizing the oral fastdisintegrating tablets (ODT) formulation for Jiawei Qing’e, a kind of prescription of Chinese herbal medicine.Methods The bitterness of Jiawei Qing’e was masked using Eudragit E-100 by solvent evaporation technique.Response surface approach was applied to investigating the interaction of formulation parameters in optimizing theformulation. The independent variables were Eudragit E-100/drug ratio (X1), amount of disintegrants (X2), and theamount of diluents (X3). The disintegration time (Y1), hardness (Y2), and weight variations of the tablets werecharacterized. Results The models predicted levels of X1= 4.63%, X2= 5.25%, and X3= 34.33%, for the optimalformulation having a hardness of 3.0 kg with the disintegration time of 30 s within experimental region. The observedresponse of Y1= 26.5 s and Y2= 3.14 kg reasonably agreed with the predicted response. Conclusion Responsesurface methodology shows the good predictability and reliability in optimizing the formulation. The optimized ODTof Jiawei Qing’e has acceptable taste, rapid disintegrating ability, and good mechanical strength.