ABSTRACT
Melt viscosity is an essential property in pharmaceutical processes such as mixing, extrusion, fused deposition modeling, and melt coating. Measuring and modeling of the melt viscosity for drug/polymer mixtures is essential for optimization of the manufacturing process. In this work, the melt viscosity of nine formulations containing the drug substances acetaminophen, itraconazole, and griseofulvin, as well as the pharmaceutical polymers Eudragit EPO, Soluplus, and Plasdone S-630, were analyzed with a rotational and oscillatory rheometer. The shear rate, temperature, and drug fraction were varied systematically to investigate their influence on viscosity. The results for the pure polymers showed typical shear-thinning behavior and are fundamental for modeling with the Carreau and Arrhenius approaches. The investigations of the viscosity of the drug/polymer mixtures resulted in a plasticizing or a filler effect, depending on the type of drug and the phase behavior. A drug shift factor was proposed to model the change in viscosity as a function of the drug fraction. On this basis, a universal model to describe the melt viscosity of drug/polymer mixtures was developed, considering shear rate, temperature, and drug fraction.
ABSTRACT
Bacteriophage Librie was isolated from a soil sample from Clarksville, TN, using the bacterium Microbacterium foliorum. Librie has a 39,941 bp genome with 62 predicted protein-coding genes and 1 predicted gene for tRNA. Based on its gene content similarity to actinobacteriophages, Librie is grouped with phages in cluster EA5.
ABSTRACT
This paper reports the genome sequences of bacteriophages isolated from soil samples using Microbacterium foliorum Phages Danno and Otwor (cluster EE) have genomes of 17,452 bp and 17,454 bp, respectively, and 25 predicted genes. The phage Scumberland (cluster EC) has a genome of 53,276 bp with 92 predicted genes.
ABSTRACT
BACKGROUND: It is widely assumed that the amount of alcohol in the blood reflects the amount of alcohol consumed. However, several factors in addition to amount of alcohol consumed can influence blood alcohol concentration (BAC). This study examines the effect of alcohol dose, concentration, and volume on BAC in rats with a high-alcohol-drinking (HAD) phenotype. METHODS: Study 1 examined the relationship between the amount of alcohol consumed and BAC. Alcohol-naïve, male, HAD rats (N = 7) were given access to alcohol for 2 h/d for 9 consecutive days with food and water ad libitum. Alcohol intake and BAC were measured at 30, 60, and 90 minutes after onset of access. Study 2 examined the effects of altering alcohol dose, concentration, and volume on BAC (as measured by area under the curve). Alcohol-naïve, male, HAD rats (N = 39) were infused, via an intragastric cannulus, with 1.16, 2.44, or 3.38 g alcohol/kg body weight (BW), produced by varying alcohol volume while holding concentration constant or by holding volume constant while varying concentration. Other rats were infused with 10, 15, or 20% v/v alcohol solutions while holding dose constant. RESULTS: BAC was more strongly correlated with the ratio of alcohol intake (g/kg BW) to total fluid intake (mls) (R = 0.85 to 0.97, p < 0.05 to p < 0.001) than it was with the amount of alcohol consumed (g/kg BW) (R = 0.70 to 0.81, p < 0.05). No effect of alcohol dose was seen during the first hour following the onset of an alcohol infusion regardless of whether dose was achieved by altering alcohol volume or concentration. After 1 hour, higher alcohol doses were predictive of greater BACs. CONCLUSIONS: The fact that a 3-fold difference in alcohol dose did not result in significant differences in BACs during the first 30 minutes after ingestion of alcohol has potentially important implications for interpretation of studies that measure alcohol-sensitive end points during this time.
