Evaluation of a Three Compartment In Vitro Gastrointestinal Simulator Dissolution Apparatus to Predict In Vivo Dissolution

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109359/1/jps24112.pd

In Vivo Predictive Dissolution: Comparing the Effect of Bicarbonate and Phosphate Buffer on the Dissolution of Weak Acids and Weak Bases

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113173/1/jps24460.pd

CONVERSION OF WOODY BIOMASS TO ENERGY, CHEMICALS AND MATERIALS

Conversion of renewable biomass to chemicals and energy is imperative to sustain our way of life as known to today. Fossil fuels have become the predominant energy source today. However, fossil deposits are limited and not renewable. Biomass is a reliable source of chemicals and energy that can be replenished at the rate of our needs. The biorefinery is a concept for the collection of processes used to convert biomass to chemicals and energy. The Biorefinery is a “catch and release” way of using carbon that is beneficial to the environment and the economy. Discussions are made for the elements of the wood-based biorefinery as proposed at SUNY ESF (College of Environmental Science and Forestry): hot-water extraction, hydrolysis, membrane separation / concentration, pulping, and biological conversion of sugars to biofuels, chemical, and biopolymers, conversion of residual woody biomass to reconstituted wood products. Hemicelluloses are the most easily separable main component of woody biomass and thus form the bulk of the extracts obtained in hot-water extraction of wood. Hydrolysis of hemicelluloses produces 5-carbon sugars (mainly xylose), 6-carbon sugars (mainly glucose and mannose), and acetic acid. Fermentation of wood extract hydrolysate can produce biofuel: ethanol and butanol. Brief discussions will also be presented on the utilization of the residual woodchips: pulp and paper, reconstituted wood products, wood pellets, and burning / gasification for energy. Hemicellulose contributes to the weight but not much to the strength of the material and thus hemicellulose-extracted woody biomass might produce lighter stronger particle board products

The solubility–permeability interplay in using cyclodextrins as pharmaceutical solubilizers: Mechanistic modeling and application to progesterone

A quasi-equilibrium mass transport analysis has been developed to quantitatively explain the solubility–permeability interplay that exists when using cyclodextrins as pharmaceutical solubilizers. The model considers the effects of cyclodextrins on the membrane permeability ( P m ) as well as the unstirred water layer (UWL) permeability ( P aq ), to predict the overall effective permeability ( P eff ) dependence on cyclodextrin concentration ( C CD ). The analysis reveals that: (1) UWL permeability markedly increases with increasing C CD since the effective UWL thickness quickly decreases with increasing C CD ; (2) membrane permeability decreases with increasing C CD , as a result of the decrease in the free fraction of drug; and (3) since P aq increases and P m decreases with increasing C CD , the UWL is effectively eliminated and the overall P eff tends toward membrane control, that is, P eff  ≈  P m above a critical C CD . Application of this transport model enabled excellent quantitative prediction of progesterone P eff as a function of HPΒCD concentrations in PAMPA assay, Caco-2 transepithelial studies, and in situ rat jejunal-perfusion model. This work demonstrates that when using cyclodextrins as pharmaceutical solubilizers, a trade-off exists between solubility increase and permeability decrease that must not be overlooked; the transport model presented here can aid in striking the appropriate solubility–permeability balance in order to achieve optimal overall absorption. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 2739–2749, 2010Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71376/1/22033_ftp.pd

The development of an earth resources information system using aerial photographs and digital computers

Analytical photogrammetry demonstrated that automatic three dimensional mapping of forest terrain was technically feasible. The examples were black and white photography at scales of 1:10,000 and 1:24,000. The major improvement in terrain modelling was the addition of the capability of joining small quadrangles together to form one large model about equal to the effective area of the pair of photographs. Improvements of somewhat lesser importance include: (1) the use of up to 16 grey levels; (2) the elimination of several coordinate transformations; and (3) the annotation of three-tone hysocline maps with elevations

ETHANOL PRODUCTION FROM A MEMBRANE PURIFIED HEMICELLULOSIC HYDROLYSATE DERIVED FROM SUGAR MAPLE BY PICHIA STIPITIS NRRL Y-7124

In an effort to devise inexpensive and sustainable production of ethanol fuel, experiments were conducted to establish conditions for Pichia stipitis NRRL Y-7124 to ferment a membrane treated wood hydrolysate derived from sugar maple to produce ethanol. The degree of aeration required to effectively utilize xylose, produce ethanol, and minimize xylitol formation as well as the optimal hydrolysate concentration were the conditions examined. P. stipitis produced the highest concentrations of ethanol in shake flasks at 150 rpm (14.3 g/L in 71 h), and 50% hydrolysate maximized ethanol yield (12.4 g/L in 51.5 h). In the 50% hydrolysate cultures, P. stipitis produced ethanol at a rate of 0.24 g/Lh with a yield of 0.41 g ethanol/g wood-derived carbohydrate

Magnetic resonance imaging quantification of fasted state colonic liquid pockets in healthy humans

The rate and extent of drug dissolution and absorption from solid oral dosage forms is highly dependent on the volume of liquid in the gastrointestinal tract (GIT). However, little is known about the time course of GIT liquid volumes after drinking a glass of water (8 oz), particularly in the colon, which is a targeted site for both locally and systemically acting drug products. Previous magnetic resonance imaging (MRI) studies offered novel insights on GIT liquid distribution in fasted humans in the stomach and small intestine, and showed that freely mobile liquid in the intestine collects in fairly distinct regions or “pockets”. Based on this previous pilot data, we hypothesized that (1) it is possible to quantify the time course of the volume and number of liquid pockets in the undisturbed colon of fasted healthy humans following ingestion of 240 mL, using noninvasive MRI methods; (2) the amount of freely mobile water in the fasted human colon is of the order of only a few milliliters. Twelve healthy volunteers fasted overnight and underwent fasted abdominal MRI scans before drinking 240 mL (∼8 fluid ounces) of water. After ingesting the water they were scanned at frequent intervals for 2 h. The images were processed to quantify freely mobile water in the total and regional colon: ascending, transverse, and descending. The fasted colon contained (mean ± SEM) 11 ± 5 pockets of resting liquid with a total volume of 2 ± 1 mL (average). The colonic fluid peaked at 7 ± 4 mL 30 min after the water drink. This peak fluid was distributed in 17 ± 7 separate liquid pockets in the colon. The regional analysis showed that pockets of free fluid were found primarily in the ascending colon. The interindividual variability was very high; the subjects showed a range of number of colonic fluid pockets from 0 to 89 and total colonic freely mobile fluid volume from 0 to 49 mL. This is the first study measuring the time course of the number, regional location, and volume of pockets of freely mobile liquid in the undisturbed colon of fasted humans after ingestion of a glass of water. Novel insights into the colonic fluid environment will be particularly relevant to improve our understanding and design of the in vivo performance of controlled release formulations targeted to the colon. The in vivo quantitative information presented here can be input into physiologically based mechanistic models of dissolution and absorption, and can be used in the design and set up of novel in vitro performance tools predictive of the in vivo environment

Mechanistic Oral Absorption Modeling and Simulation for Formulation Development and Bioequivalence Evaluation: Report of an FDA Public Workshop

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138394/1/psp412204.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138394/2/psp412204_am.pd

Face and tone of voice in the communication of deception

The contributions of face and tone of voice (filtered speech) to the communication of honest and deceptive messages were examined. In general, tone of voice was a better source of deception and leakage than the face. In addition, raters' judgments of the combined audiovisual channel were better predicted from their judgments of tone of voice when the message was deceptive and from their judgments of the face when the message was honest. The relative importance of face and tone of voice was also affected by the availability of verbal contentwhen content was available the face became less important. Thus, judges obtained more information from facial cues that were added to filtered speech (a comparison between filtered speech and face plus filtered speech) than from facial cues that were added to the full voice (a comparison between the voice and face plus voice). In addition, judgments of the audiovisual channel without content (face plus filtered speech) were better predicted from judgments of the face, whereas judgments of the audiovisual channel with content (face plus full voice) were better predicted from judgments of filtered speech. Finally, the relative importance of face and tone of voice was also determined by the affect that was communicated. Tone of voice was a better source of information about dominance and submission; the face revealed more information and was more highly correlated with the combined audiovisual channel for communications of liking and disliking

Biowaiver monographs for immediate release solid oral dosage forms: acetaminophen (paracetamol).

Literature data are reviewed on the properties of acetaminophen (paracetamol) related to the biopharmaceutics classification system (BCS). According to the current BCS criteria, acetaminophen is BCS Class III compound. Differences in composition seldom, if ever, have an effect on the extent of absorption. However, some studies show differences in rate of absorption between brands and formulations. In particular, sodium bicarbonate, present in some drug products, was reported to give an increase in the rate of absorption, probably caused by an effect on gastric emptying. In view of Marketing Authorizations (MAs) given in a number of countries to acetaminophen drug products with rapid onset of action, it is concluded that differences in rate of absorption were considered therapeutically not relevant by the Health Authorities. Moreover, in view of its therapeutic use, its wide therapeutic index and its uncomplicated pharmacokinetic properties, in vitro dissolution data collected according to the relevant Guidances can be safely used for declaring bioequivalence (BE) of two acetaminophen formulations. Therefore, accepting a biowaiver for immediate release (IR) acetaminophen solid oral drug products is considered scientifically justified, if the test product contains only those excipients reported in this paper in their usual amounts and the test product is rapidly dissolving, as well as the test product fulfils the criterion of similarity of dissolution profiles to the reference product