Identifying critical process steps to protein stability during spray drying using a vibrating mesh or a two-fluid nozzle.

The aim of this study was to identify critical steps to protein stability during spray drying using two different nozzle types: a vibrating mesh nozzle and a standard two-fluid nozzle in a Büchi B-90 spray dryer. l-Lactic dehydrogenase was used as a model protein as it is a heat and shear stress sensitive protein. Trehalose was used as excipient because of its excellent stabilizing capacities.

The mechanism behind the biphasic pulsatile drug release from physically mixed poly(dl-lactic(-co-glycolic) acid)-based compacts.

Successful immunization often requires a primer, and after a certain lag time, a booster administration of the antigen. To improve the vaccinees' comfort and compliance, a single-injection vaccine formulation with a biphasic pulsatile release would be preferable. Previous work has shown that such a release profile can be obtained with compacts prepared from physical mixtures of various poly(dl-lactic(-co-glycolic) acid) types (Murakami et al.

Ovalbumin-containing core-shell implants suitable to obtain a delayed IgG1 antibody response in support of a biphasic pulsatile release profile in mice.

A single-injection vaccine formulation that provides for both a prime and a boost immunization would have various advantages over a multiple-injection regime. For such a vaccine formulation, it is essential that the booster dose is released after a certain, preferably adjustable, lag time. In this study we investigated whether a core-shell based implant, containing ovalbumin as core material and poly(DL-lactic-co-glycolic acid) of various monomer ratios as shell material can be used to obtain such a booster release.

Efficient production of solid dispersions by spray drying solutions of high solid content using a 3-fluid nozzle.

To evaluate the feasibility of producing solid dispersions with 3-fluid nozzle spray drying to improve the dissolution behavior of lipophilic drugs, 60 experiments were performed based on a Design of Experiment. Solid dispersions with mannitol as a hydrophilic matrix and diazepam as a model drug with a drug load of 20 wt-% were produced. The variables of the experiments were the water/organic solvent ratio, liquid feed flow, total solid content, atomizing airflow and type of organic solvent (ethanol or ethyl acetate).

Recent advances in the fundamental understanding of adhesive mixtures for inhalation.

Adhesive mixtures for inhalation are the most widely used type of formulation in dry powder inhalation products. Although they have been the subject of active research, the relationships between properties of the starting materials, the mixing and dispersion processes, and the dispersion performance of this type of formulation are generally poorly understood. Interactions between relevant variables have been mentioned as an important cause.

A user-friendly model for spray drying to aid pharmaceutical product development.

The aim of this study was to develop a user-friendly model for spray drying that can aid in the development of a pharmaceutical product, by shifting from a trial-and-error towards a quality-by-design approach. To achieve this, a spray dryer model was developed in commercial and open source spreadsheet software. The output of the model was first fitted to the experimental output of a Büchi B-290 spray dryer and subsequently validated.

Preparation of drug nanocrystals by controlled crystallization: application of a 3-way nozzle to prevent premature crystallization for large scale production.

In a previous study we have developed a novel process to produce drug nanocrystals. This process, "controlled crystallization during freeze-drying" has shown to be a successful method to increase the dissolution rate of poorly water-soluble drugs [de Waard, H., Hinrichs, W.