Powder Characteristics of Proteins Spray-Dried from Different Spray-Dryers

Combined effects of spray-drying conditions and postdrying storage time and temperature on Salmonella choleraesuis and Salmonella typhimurium survival when inoculated in liquid porcine plasma

The objective of this study was to determine the effectiveness of the spray-drying process on the inactivation of Salmonella choleraesuis and Salmonella typhimurium spiked in liquid porcine plasma and to test the additive effect of immediate postdrying storage. Commercial spray-dried porcine plasma was sterilized by irradiation and then reconstituted (1:9) with sterile water. Aliquots of reconstituted plasma were inoculated with either S. choleraesuis or S. typhimurium, subjected to spray-drying at an inlet temperature of 200°C and an outlet temperature of either 71 or 80°C, and each spray-drying temperature combinations were subjected to either 0, 30 or 60 s of residence time (RT) as a simulation of residence time typical of commercial dryers. Spray-dried samples were stored at either 4·0 ± 3·0°C or 23·0 ± 0·3°C for 15 days. Bacterial counts of each Salmonella spp., were completed for all samples. For both Salmonella spp., spray-drying at both outlet temperatures reduced bacterial counts about 3 logs at RT 0 s, while there was about a 5·5 log reduction at RT 60 s. Storage of all dried samples at either 4·0 ± 3·0°C or 23·0 ± 0·3°C for 15 days eliminate all detectable bacterial counts of both Salmonella spp.

SIGNIFICANCE AND IMPACT OF THE STUDY

Safety of raw materials from animal origin like spray-dried porcine plasma (SDPP) may be a concern for the swine industry. Spray-drying process and postdrying storage are good inactivation steps to reduce the bacterial load of Salmonella choleraesuis and Salmonella typhimurium. For both Salmonella spp., spray-drying at 71°C or 80°C outlet temperatures reduced bacterial counts about 3 log at residence time (RT) 0 s, while there was about a 5.5 log reduction at RT 60 s. Storage of all dried samples at either 4.0 ± 3.0°C or 23.0 ± 0.3°C for 15 days was effective for eliminating detectable bacterial counts of both Salmonella spp.

An Inhalable Powder Formulation Based on Micro- and Nanoparticles Containing 5-Fluorouracil for the Treatment of Metastatic Melanoma

Melanoma is the most aggressive and lethal type of skin cancer, with a poor prognosis because of the potential for metastatic spread. The aim was to develop innovative powder formulations for the treatment of metastatic melanoma based on micro- and nanocarriers containing 5-fluorouracil (5FU) for pulmonary administration, aiming at local and systemic action. Therefore, two innovative inhalable powder formulations were produced by spray-drying using chondroitin sulfate as a structuring polymer: (a) 5FU nanoparticles obtained by piezoelectric atomization (5FU-NS) and (b) 5FU microparticles of the mucoadhesive agent Methocel™ F4M for sustained release produced by conventional spray drying (5FU-MS). The physicochemical and aerodynamic were evaluated in vitro for both systems, proving to be attractive for pulmonary delivery. The theoretical aerodynamic diameters obtained were 0.322 ± 0.07 µm (5FU-NS) and 1.138 ± 0.54 µm (5FU-MS). The fraction of respirable particles (FR%) were 76.84 ± 0.07% (5FU-NS) and 55.01 ± 2.91% (5FU-MS). The in vitro mucoadhesive properties exhibited significant adhesion efficiency in the presence of Methocel™ F4M. 5FU-MS and 5FU-NS were tested for their cytotoxic action on melanoma cancer cells (A2058 and A375) and both showed a cytotoxic effect similar to 5FU pure at concentrations of 4.3 and 1.7-fold lower, respectively.

Formation, characterization, and fate of inhaled drug nanoparticles

Nanoparticles bring many benefits to pulmonary drug delivery applications, especially for systemic delivery and drugs with poor solubility. They have recently been explored in pressurized metered dose inhaler, nebulizer, and dry powder inhaler applications, mostly in polymeric forms. This article presents a review of processes that have been used to generate pure (non polymeric) drug nanoparticles, methods for characterizing the particles/formulations, their in-vitro and in-vivo performances, and the fate of inhaled nanoparticles.

Commercially produced spray-dried porcine plasma contains increased concentrations of porcine circovirus type 2 DNA but does not transmit porcine circovirus type 2 when fed to naive pigs

The porcine circovirus type 2 (PCV2) antibody and DNA status of porcine plasma products collected during the commercial spray-drying process were evaluated. Samples evaluated included 52 pooled liquid plasma (fresh) samples collected at 14 regional abattoirs before transport to 1 of 2 spray-drying facilities, 32 pooled liquid plasma (concentrated) samples collected after arrival at the spray-drying facilities at different stages before the spray-drying process, and 32 samples in powdered form (spray-dried) collected after spray drying. All 116 samples were positive for PCV2 antibody, with PCV2 ELISA sample-to-positive ratios ranging from 9.2 to 13.6 on a DM basis. Porcine circovirus type 2 DNA (4.5 to 7.9 log(10) PCV2 copies/mL, DM basis) was present in 82.7% (43/52) of the fresh plasma samples, 71.9% (23/32) of the concentrated plasma samples and 78.1% (25/32) of the spray-dried plasma samples, with a greater prevalence of PCV2b than PCV2a. To determine the infectivity of PCV2 DNA-positive commercial spray-dried plasma, nine 10-wk-old 68-kg PCV2-naïve pigs were randomly assigned to 1 of 3 treatment groups and rooms: 1) a negative control (no plasma in the feed, not inoculated with PCV2); 2) a positive control (no plasma in the feed, inoculated with PCV2); and 3) plasma-fed pigs (4% porcine plasma in the feed for 42 d, not inoculated with PCV2). All positive control pigs became viremic by 7 d postinoculation and seroconverted by 42 d postinoculation, whereas pigs in the negative control group and in the spray-dried plasma group were PCV2 PCR negative and did not seroconvert to PCV2 for the duration of the study. The results indicate that PCV2 DNA and antibodies are commonly found in commercial spray-dried plasma. However, no evidence of infectivity of the PCV2 DNA was found in naïve pigs when commercial spray-dried plasma was included in the diet under the conditions of this study.

Scaling up the spray drying process from pilot to production scale using an atomized droplet size criterion

PURPOSE

The purpose of this study was to investigate the possibility of producing identical powders in pilot and production scale spray drying equipment by matching the droplet size distributions produced by two differently sized atomizers.

METHODS

Particles were prepared by spray drying solutions of acetaminophen and polyvinylpyrrolidone K-30. The success of the up-scaling was evaluated by comparing the powders in terms of particle size distribution (laser diffraction), crystallinity (XPRD) and morphology (SEM). Furthermore, the influence of process parameters on other product characteristics such as stability and residual volatile content was also evaluated.

RESULTS

The spray drying experiments resulted in spherical, amorphous particles with volumetric median diameters of typically 4-10 microm for pilot scale and 4-30 microm for production scale. The results showed that particles with similar morphology and crystallinity could be produced in the two applied spray dryers. However, scale-up based purely on matching droplet size distributions was not feasible.

CONCLUSIONS

The scale-up criterion did not account for the differences between the droplet-drying gas mixing and residence time distribution within the two spray dryers. Therefore, production scale experiments are required in order to obtain similar product characteristics as in pilot scale.

Sodium pantoprazole-loaded enteric microparticles prepared by spray drying: Effect of the scale of production and process validation

Pantoprazole is a prodrug used in the treatment of acid related disorders and Helicobacter pylori infections. It is activated inside gastric parietal cells binding irreversibly to the H(+)/K(+)-ATPase. In this way, pantoprazole must be absorbed intact in the intestinal tract, which indicates that enteric drug delivery systems are required for its oral administration. The purpose of this study was to investigate the physical characteristics of enteric pantoprazole-loaded microparticles prepared by spray drying using a blend of Eudragit S100 and HPMC. The microparticles were produced in different spray dryers and operational conditions at laboratory and pilot scales. Microparticles produced with two fluid nozzle atomizer and air pressure of 196 kPa presented satisfactory encapsulation efficiency and gastro-resistance. Microparticles produced with the same atomizer but using 49 kPa of air pressure presented strings in the powder. The microparticles produced in mixed flow presented very high polydispersity and the ones produced with rotating disc atomizer presented drug crystals adsorbed on the particle surfaces. The microparticles produced with two fluid nozzle atomizer and 196 kPa were prepared in three consecutive days for the process validation. The powders showed reproducible diameter, polydispersity, densities, encapsulation efficiency and gastro-resistance profile.