Spray dried oleanolic acid powder for pulmonary delivery

Poster Presentation: no. 13PS51The abstract of the poster presentation is located at http://inhalationasia.org/index.php/poster-presentations/176-13ps51-shuangning-chenIntroduction: Oleanolic acid (OA), well known for its hepatoprotective effect, has been shown in vitro to be cytotoxic in A549 human non-small-cell lung cancer cell line. Thus it may be potentially useful for lung cancer treatment. Being a BCS Class IV drug, it has low oral bioavailability. Therefore, inhalation is the preferred route of administration for local delivery. The aim of this study is to develop an inhalable oleanolic acid dry powder formulation .....published_or_final_versio

Exposure to selective serotonin reuptake inhibitors during pregnancy and risk of autism spectrum disorder in children: A systematic review and meta-analysis of observational studies

postprin

Evidence for the existence of powder sub-populations in micronized materials : Aerodynamic size-fractions of aerosolized powders possess distinct physicochemical properties

This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Purpose: To investigate the agglomeration behaviour of the fine ( 12.8 µm) particle fractions of salmeterol xinafoate (SX) and fluticasone propionate (FP) by isolating aerodynamic size fractions and characterising their physicochemical and re-dispersal properties. Methods: Aerodynamic fractionation was conducted using the Next Generation Impactor (NGI). Re-crystallized control particles, unfractionated and fractionated materials were characterized for particle size, morphology, crystallinity and surface energy. Re-dispersal of the particles was assessed using dry dispersion laser diffraction and NGI analysis. Results: Aerosolized SX and FP particles deposited in the NGI as agglomerates of consistent particle/agglomerate morphology. SX particles depositing on Stages 3 and 5 had higher total surface energy than unfractionated SX, with Stage 5 particles showing the greatest surface energy heterogeneity. FP fractions had comparable surface energy distributions and bulk crystallinity but differences in surface chemistry. SX fractions demonstrated higher bulk disorder than unfractionated and re-crystallized particles. Upon aerosolization, the fractions differed in their intrinsic emission and dispersion into a fine particle fraction (< 5.0 µm). Conclusions: Micronized powders consisted of sub-populations of particles displaying distinct physicochemical and powder dispersal properties compared to the unfractionated bulk material. This may have implications for the efficiency of inhaled drug deliveryPeer reviewe

Spray dried oleanolic acid powder for pulmonary delivery

Conference Theme: Pharmaceutical Materials Science and Engineering - Characterization and Applicatio

Parameters affecting in-liquid drying microencapsulation and release rate of cefaclor

An in-liquid drying microencapsulation method for producing sustained release cefaclor (CF) microspheres has been developed. Sieved fractions of CF monohydrate particles together with polyvinylpyrrolidone (M-w similar to 40 000) were dispersed in a solvent mixture of dichloromethane with cyclohexane (40:60 v/v) containing dissolved ethylcellulose (EC; 48-49.5% ethoxy content). Encapsulation was effected by adding the dispersion to a stirred aqueous medium saturated with CF. The resulting microspheres (collected overnight and oven-dried at 40 degrees C) were examined for size and surface features by scanning electron microscopy, and for solid-state interactions and phase changes using differential scanning calorimetry (DSC), thermogravimetric analysis and powder X-ray diffractometry. The rate and extent of CF release in aqueous medium was measured at 37 degrees C using the USP rotating basket method at 100 rpm. The size, degree of sphericity, and rate of CF release of the microspheres were all shown to depend on the CF to EC mass ratio and the stirring speed employed in encapsulation. Higher EC to CF mass ratio and lower stirring speed afforded microspheres with slower release rate of CF. The rate of CF release from the microspheres fit the simplified Higuchi's planar model equation, and for the samples prepared at various EC:CF ratios, exhibited a strong correlation with drug loading (r =0.98; n=4 (mean values); p <0.05). DSC studies on the samples indicated an absence of molecular interactions between EC and CF in the microspheres. The results demonstrate that the in-liquid drying method, if appropriately optimized, could be used to produce sustained-release CF microspheres with the desired release pattern and physical properties. (C) 1998 Elsevier Science B.V. All rights reserved

Inhalable oleanolic acid-hypromellose particles for controlled release

Track 5. Micro/Nano devices for Life Sciences and their fabrication - Poster Presentation: abstract no. 820

Predicting the aerosol performance of dry powder inhalation formulations by interparticulate interaction analysis using inverse gas chromatography

Previous studies have demonstrated the utility of inverse gas chromatography (IGC) in discriminating the differences in surface energy between salmeterol xinafoate (SX) powders prepared by conventional sequential batch crystallization and micronization and by supercritical fluid crystallization. In the present study, solubility parameters derived from IGC analysis at infinite dilution (zero coverage) were further utilized to evaluate the influence of solid-solid interactions on the in vitro aerosol performance of these SX samples, with or without the inclusion of a lactose carrier. To this end, the strength of cohesive SX-SX interactions and that of adhesive SX-lactose interactions were computed for the samples from the corresponding solubility parameters, and their fine particle fractions determined using a multi-stage liquid impinger. It was found that the aerosol performance of SX could be substantially improved by the addition of lactose carrier only if the adhesive SX-lactose interactions were stronger than the cohesive SX-SX interactions. The difference in strength between these two forms of interactions also displayed a significant correlation with the increase in fine particle fraction after the addition of lactose carrier. These results suggest that IGC-based interparticulate interaction measurements may serve as a useful means for predicting the aerosol performance of dry powder inhalation formulations. (c) 2005 Wiley-Liss, Inc