Comparative biologies of Oryzaephilus surinamensis and O. mercator (Coleoptera: Cucujidae) on dried fruits and nuts /

Issued Nov. 1974.

School lunch recipes using dried fruits /

"August 1948."

Freezing rain experiments, Project Freeze; final report. Contract no. Nonr-2250(00)

Mode of access: Internet.

Relating the stickiness property of foods undergoing drying and dried products to their surface energetics

Stickiness is a common problem encountered in food handling and processing, and also during consumption. Stickiness is observed as adhesion of the food to processing equipment surfaces or cohesion within the food particulate or mass. An important operation where this undesirable behavior of food is manifested is drying. This occurs particularly during drying of high-sugar and high-fat foods. To date, the stickiness of foods during drying or dried powder has been investigated in relation to their viscous and glass transition properties. The importance of contact surface energy of the equipment has been ignored in many analyses, despite the fact that some drying operations have reported using low-energy contact surfaces in drying equipment to avoid the problems caused by stickiness. This review discusses the fundamentals of adhesion and cohesion mechanisms and relates these phenomena to drying and dried products.

RP-HPLC detection of a sulphiting-induced artefact from paeoniflorin in dried roots of Paeonia lactiflora

Paeoniflorin is one of the bioactive ingredients of the roots of Paeonia lactiflora (Paeoniaceae). A comparative study of processed and non-processed commercial samples of dried roots of P. lactiflora indicated a very low level of paeoniflorin in the processed sample and the formation of a new more polar component, sodium paeoniflorin sulphonate, during treatment of the roots with sulphiting agents. Copyright (c) 2006 John Wiley & Sons, Ltd.

αα'-trehalose 6,6'-dibehenate in non-phospholipid-based liposomes enables direct interaction with trehalose, offering stability during freeze-drying

Trehalose is a well known protector of biostructures like liposomes and proteins during freeze-drying, but still today there is a big debate regarding its mechanism of action. In previous experiments we have shown that trehalose is able to protect a non-phospholipid-based liposomal adjuvant (designated CAF01) composed of the cationic dimethyldioctadecylammonium (DDA) and trehalose 6,6-dibehenate (TDB) during freeze-drying [D. Christensen, C. Foged, I. Rosenkrands, H.M. Nielsen, P. Andersen, E.M. Agger, Trehalose preserves DDA/TDB liposomes and their adjuvant effect during freeze-drying, Biochim. Biophys. Acta, Biomembr. 1768 (2007) 2120-2129]. Furthermore it was seen that TDB is required for the stabilizing effect of trehalose. Herein, we show using the Langmuir-Blodgett technique that a high concentration of TDB present at the water-lipid interface results in a surface pressure around 67 mN/m as compared to that of pure DDA which is approximately 47 mN/m in the compressed state. This indicates that the attractive forces between the trehalose head group of TDB and water are greater than those between the quaternary ammonium head group of DDA and water. Furthermore, addition of trehalose to a DDA monolayer containing small amounts of TDB also increases the surface pressure, which is not observed in the absence of TDB. This suggests that even small amounts of trehalose groups on TDB present at the water-lipid interface associate free trehalose to the liposome surface, presumably by hydrogen bonding between the trehalose head groups of TDB and the free trehalose molecules. Hence, for CAF01 the TDB component not only stabilizes the cationic liposomes and enhances the immune response but also facilitates the cryo-/lyoprotection by trehalose through direct interaction with the head group of TDB. Furthermore the results indicate that direct interaction with liposome surfaces is necessary for trehalose to enable protection during freeze-drying.

Carbomer-modified spray-dried respirable powders for pulmonary delivery of salbutamol sulphate

The present study investigates the feasibility of using two types of carbomer (971 and 974) to prepare inhalable dry powders that exhibit modified drug release properties. Powders were prepared by spray-drying formulations containing salbutamol sulphate, 20-50% w/w carbomer as a drug release modifier and leucine as an aerosolization enhancer. Following physical characterization of the powders, the aerosolization and dissolution properties of the powders were investigated using a Multi-Stage Liquid Impinger and a modified USP II dissolution apparatus, respectively. All carbomer 974-modified powders and the 20% carbomer 971 powder demonstrated high dispersibility, with emitted doses of at least 80% and fine particle fractions of approximately 40%. The release data indicated that all carbomer-modified powders displayed a sustained release profile, with carbomer 971-modified powders obeying first order kinetics, whereas carbomer 974-modified powders obeyed the Higuchi root time kinetic model; increasing the amount of carbomer 971 in the formulation did not extend the duration of drug release, whereas this was observed for the carbomer 974-modified powders. These powders would be anticipated to deposit predominately in the lower regions of the lung following inhalation and then undergo delayed rather than instantaneous drug release, offering the potential to reduce dosing frequency and improve patient compliance.

Sustained delivery by leucine-modified chitosan spray-dried respirable powders

The controlled co-delivery of multiple agents to the lung offers potential benefits to patients. This study investigated the preparation and characterisation of highly respirable spray-dried powders displaying the sustained release of two chemically distinct therapeutic agents. Spray-dried powders were produced from 30% (v/v) aqueous ethanol formulations that contained hydrophilic (terbutaline sulphate) and hydrophobic (beclometasone dipropionate) model drugs, chitosan (as a drug release modifier) and leucine (aerosolisation enhancer). The influence of chitosan molecular weight on spray-drying thermal efficiency, aerosol performance and drug release profile was investigated. Resultant powders were physically characterised: with in vitro aerosolisation performance and drug release profile investigated by the Multi-Stage Liquid Impinger and modified USP II dissolution apparatus, respectively. It was found that increased chitosan molecular weight gave increased spray-drying thermal efficiency. The powders generated were of a suitable size for inhalation—with emitted doses over 90% and fine particle fractions up to 72% of the loaded dose. Sustained drug release profiles were observed in dissolution tests for both agents: increased chitosan molecular weight associated with increased duration of drug release. The controlled co-delivery of hydrophilic and hydrophobic entities underlines the capability of spray drying to produce respirable particles with sustained release for delivery to the lung. (c) 2009 Elsevier B.V. All rights reserved.

Modified release of beclometasone dipropionate from chitosan-basedd spray-dried respirable powders

Dry powders for inhalation were prepared by spray drying a 30% v/v aqueous ethanol formulation containing beclometasone dipropionate (BDP), lactose, leucine and chitosan (low, medium or high molecular weight (MW), or combinations thereof). Following physical characterisation of the powders, the aerosolisation and dissolution properties of the powders were investigated using Multi-Stage Liquid Impinger and USP II dissolution apparatus, respectively. The powders were highly dispersible, with emitted doses in excess of 90% of loaded powder aerosolised from a Spinhaler dry powder inhaler. The fine particle fraction (FPF) was observed to decrease, whereas the time for 100% drug release increased, with increasing chitosan MW. For example, the low MW formulation exhibited an FPF of 64% and a 100% dissolution time of 2 h, whereas the high MW formulation demonstrated an FPF of 54% and a dissolution time of 12 h. These powders would be anticipated to deposit predominately in the lower regions of the lung following inhalation, and then undergo delayed rather than instantaneous drug release, offering the potential to reduce dosing frequency and improve patient compliance. (c) 2008 Elsevier B.V. All rights reserved.

Chitosan-based spray-dried respirable powders for sustained delivery of terbutaline sulfate

In this study, we describe the preparation of highly dispersible dry powders for pulmonary drug delivery that display sustained drug release characteristics. Powders were prepared by spray-drying 30% v/v aqueous ethanol formulations containing terbutaline sulfate as a model drug, chitosan as a drug release modifier and leucine as an aerosolisation enhancer. The influence of chitosan molecular weight on the drug release profile was investigated by using low, medium and high molecular weight chitosan or combinations thereof. Following spray-drying, resultant powders were characterised using scanning electron microscopy, laser diffraction, tapped density analysis, differential scanning calorimetry and thermogravitational analysis. The in vitro aerosolisation performance and drug release profile were investigated using Multi-Stage Liquid Impinger analysis and modified USP II dissolution apparatus, respectively. The powders generated were of a suitable aerodynamic size for inhalation, had low moisture content and were amorphous in nature. The powders were highly dispersible, with emitted doses of over 90% and fine particle fractions of up to 82% of the total loaded dose, and mass median aerodynamic diameters of less than 2.5microm. A sustained drug release profile was observed during dissolution testing; increasing the molecular weight of the chitosan in the formulation increased the duration of drug release. (c)2007 Elsevier B.V. All rights reserved.

Spray-dried powders for pulmonary drug delivery

Powders for inhalation are traditionally prepared using a destructive micronization process such as jet milling to reduce the particle size of the drug to 2-5 μm. The resultant particles are typically highly cohesive and display poor aerosolization properties, necessitating the addition of a coarse carrier particle to the micronized drug to improve powder flowability. Spray-drying technology offers an alternative, constructive particle production technique to the traditional destructive approach, which may be particularly useful when processing biotechnology products that could be adversely affected by high-energy micronization processes. Advantages of spray drying include the ability to incorporate a wide range of excipients into the spray-drying feedstock, which could modify the aerosolization and stability characterizations of the resultant powders, as well as modify the drug release and absorption profiles following inhalation. This review discusses some of the reasons why pulmonary drug delivery is becoming an increasingly popular route of administration and describes the various investigations that have been undertaken in the preparation of spray-dried powders for pulmonary drug delivery. © 2007 by Begell House, Inc.