Optimization of a freeze-drying cycle of a viral vaccine based on changes in temperature, time and geometry of the vials.

The freeze-drying process is used in pharmaceutical industry, however in terms of process management, the process must be avoided at all cost because it has several disadvantages such as high equipment investment, high energy demand, a process that requires long times and products easily to moisturize and fragile and needs to be carefully packed and stored. This work aims at reducing the freeze-drying cycle time of a viral product and consider loading this product at subzero temperatures to increase productivity of this product. Experiments were carried out with freeze-drying cycles with less 15 and 20h in comparison to the original cycle. The experiments were performed with the same formulation of the commercial batch and using a pilot freeze dryer. Modifications were made in the physical properties of the current freeze-drying cycle (temperature, pressure and time) and the loading temperature of the product, without changing the formulation of the vaccine or primary loading. Samples of the lyophilized product trial were analyzed for their appearance, performance, residual moisture, strength and accelerated thermostability in the amount currently used by the company quality control. All the results were within the specifications of the company were close to or better when compared to commercial batches.

Batch and fixed-bed column biosorption of manganese ion by sargassum filipendula

This paper presents experimental data of the biosorption of manganese onto Sargassum filipendula in both batch and fixed-bed column systems. Batch equilibrium data were used for nonlinear fittings of the Langmuir and Freundlich isotherms. A mathematical model based on mass balances in the fluid and in the sorbent was applied to represent the experimental fixed-bed column data. The utilization of isotherm parameters from the batch experiments in the breakthrough model implied a significant mismatch in relation to the laboratory data. Alternatively, additional fixed-bed column data provided new parameters for the isotherm evaluation, and the corresponding simulated profile of the breakthrough curve reached better agreement to the experimental results.