Optimization of the fabrication, stability, and performance of food grade nanoemulsions with low and high energy methods

There is interest in the production of emulsions by low-energy methods because no expensive equipment is required thus making emulsion formation inexpensive and simple to implement. The goal of this research is to establish the major factors that affect emulsion formation using low-energy methods and possible applications of the emulsions and nanoemulsions formed by this method. Lastly, the use of natural emulsifiers with low- and high-energy methods was investigated. Initially, formation of nanoemulsions using isothermal low energy methods was investigated with a model system (hexadecane, Brij 30). Preliminary experiments showed that nanoemulsions could only be formed when the surfactant was initially mixed in with the oil phase. The major factors that affected particle size included order of addition, surfactant concentration, and storage temperature, while addition rate and stirring speed had minimal effects. The optimal formulation conditions were determined to be at a surfactant-to-oil ratio (SOR) of 0.375, an addition time of 5 minutes, and a stir speed of 700 rpm for both spontaneous emulsification and emulsion phase inversion methods. Additionally, emulsions could be stored for up to a month at temperatures less than 25°C without showing any instability. Experiments were then carried out to establish which factors affect nanoemulsion formation when using food grade ingredients and the spontaneous emulsification method. Droplet size decreased with increasing SOR and was smallest when the non-ionic surfactant Tween 80 was utilized. In order for spontaneous emulsification to occur, the surfactant had to be initially dissolved in the organic phase rather than the aqueous phase. Oil composition affected particle size with medium chain triglycerides (MCT) forming the smallest droplets followed by flavor oils and then long chain triglycerides forming the largest droplets. However, no physiochemical correlation could be made between oil characteristics and particle size. The results obtained using spontaneous emulsification were then compared to those obtained using emulsion phase inversion and similarities were found, implying a common underlying mechanism for the two methods. Next, the formation of nanoemulsions using the spontaneous emulsification method was demonstrated in a model food system: a gelatin-based dessert. The influence of preparation and storage conditions on nanoemulsion formation and stability were investigated. Droplet size decreased with increasing preparation temperature. Translucent filled hydrogels could be formed by incorporating nanoemulsions into the gelatin system. Optical and rheological properties remained unchanged with emulsion incorporation into a model gelatin gel and commercial gelatin dessert. The use of spontaneous emulsification to produce nanoemulsions may be helpful in the production of functional food gels. Finally, sunflower phospholipids were investigated as an emulsifier using spontaneous emulsification. Initial particle diameter was influenced by phospholipid composition, phospholipid concentration, initial phospholipid location, and storage time. Relatively large emulsion droplets (d \u3e 10 mm) could be formed which means it is possible to form emulsions using natural emulsifiers when fine droplets are not essential. However, often fine droplets are more desirable so the use of sunflower phospholipids with the high energy method of microfluidization was also investigated to see if an w-3 fatty acid nanoemulsion delivery system could be formed. Relatively small droplets (d \u3c 150 nm) could be formed by optimizing the phospholipid type and concentration. These results suggest that sunflower phospholipids are a viable emulsifier choice to form nanoemulsions and have added benefits due to their low allergenicity and non-genetically modified sources

Study of intragastric structuring ability of sodium alginate based o/w emulsions under in vitro physiological pre-absorptive digestion conditions

In the present work, the intragastric structuring ability of o/w emulsions either stabilised (1–4%, w/w of sodium alginate (SA)) or structured with sheared ionic gel (1–3%, w/w of SA crosslinked with Ca2+) in the absence (saliva and gastric phases constituted of deionised water) or presence of in vitro pre-absorptive conditions (physiological simulated saliva and gastric fluids) was investigated. Visualisation of the morphological aspects of the gastric chymes, in the absence of multivalent counterions, demonstrated that SA stabilised systems underwent a remarkable swelling in the pH range of 2–3, whilst at the same pH range, ionic SA gel structured systems maintained their major structure configuration. When the aforementioned systems were exposed to physiological intragastric fluids, a reduction of the length and the hydrodynamic volume of the alginate fibres was detected regardless the structuring approach. On their exposure to physiological intragastric conditions (pH = 2), SA stabilised emulsions underwent sol–gel transition achieving a ca. 3- to 4-order increase of storage modulus (at 1 Hz). In the case of ionic sheared gel structured emulsions, exposure to physiological intragastric fluids resulted in a 10-fold reduction ability of their acid structuring ability, most likely due to the dialysis of egg-box dimer conformations by monovalent cations and protons and the sterical hindering of hydrogen bonding of MM and GG sequences under acidic conditions. Using of non-physiological simulated intragastric fluids was associated with overestimated structuring performance of SA regardless its physical state

Use of opioids and other analgesics by older adults in the United States, 1999-2010.

Background and objectiveThere has been concern over rising use of prescription opioids in young and middle-aged adults. Much less is known about opioid prescribing in older adults, for whom clinical recommendations and the balance of risks and benefits differ from younger adults. We evaluated changes in use of opioids and other analgesics in a national sample of clinic visits made by older adults between 1999 and 2010.Design, setting, and subjectsObservational study of adults aged 65 and older from the 1999-2010 National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey, serial cross-sectional surveys of outpatient visits in the United States.MethodsMedication use was assessed at each study visit and included medications in use prior to the visit and medications newly prescribed at the visit. Results were adjusted for survey weights and design factors to provide nationally representative estimates.ResultsMean age was 75 ± 7 years, and 45% of visits occurred in primary care settings. Between 1999-2000 and 2009-2010, the percent of clinic visits at which an opioid was used rose from 4.1% to 9.0% (P < 0.001). Although use of all major opioid classes increased, the largest contributor to increased use was hydrocodone-containing combination opioids, which rose from 1.1% to 3.5% of visits over the study period (P < 0.001). Growth in opioid use was observed across a wide range of patient and clinic characteristics, including in visits for musculoskeletal problems (10.7% of visits in 1999-2000 to 17.0% in 2009-2010, P < 0.001) and in visits for other reasons (2.8% to 7.3%, P < 0.001).ConclusionsOpioid use by older adults visiting clinics more than doubled between 1999 and 2010, and occurred across a wide range of patient characteristics and clinic settings

Prescribing Quality in Older Veterans: A Multifocal Approach

Background and objectiveQuality prescribing for older adults involves multiple considerations. We evaluated multiple aspects of prescribing quality in older veterans to develop an integrated view of prescribing problems and to understand how the prevalence of these problems varies across clinically important subgroups of older adults.Design and participantsCross-sectional observational study of veterans age 65 years and older who received medications from Department of Veterans Affairs (VA) pharmacies in 2007.Main measuresUsing VA pharmacy data linked with encounter, laboratory and other data, we assessed five types of prescribing problems.Key resultsAmong 462,405 patients age 65 and older, mean age was 75 years, 98 % were male, and patients were prescribed a median of five medications. Half of patients (50 %) had one or more prescribing problems, including 12 % taking one or more medications at an inappropriately high dose, 30 % with drug-drug interactions, 3 % with drug-disease interactions, and 26 % taking one or more Beers criteria drugs. In addition, 16 % were taking a high-risk drug (warfarin, insulin, and/or digoxin). On multivariable analysis, age was not strongly associated with four of the five types of prescribing issues assessed (relative risk < 1.3 across age groups), and comorbid burden conferred substantially increased risk only for drug-disease interactions and use of high-risk drugs. In contrast, the number of drugs used was consistently the strongest predictor of prescribing problems. Patients in the highest quartile of medication use had 6.6-fold to12.5-fold greater risk of each type of prescribing problem compared to patients in the lowest quartile (P < 0.001 for each).ConclusionsThe number of medications used is by far the strongest risk factor for each of five types of prescribing problems. Efforts to improve prescribing should especially target patients taking multiple medications

Use of Opioids and Other Analgesics by Older Adults in the United States, 1999–2010

BACKGROUND & OBJECTIVE: There has been concern over rising use of prescription opioids in young and middle-aged adults. Much less is known about opioid prescribing in older adults, for whom clinical recommendations and the balance of risks and benefits differ from younger adults. We evaluated changes in use of opioids and other analgesics in a national sample of clinic visits made by older adults between 1999 to 2010. DESIGN, SETTING, SUBJECTS: Observational study of adults age 65 and older from the 1999–2010 National Ambulatory and National Hospital Ambulatory Medical Care Surveys, serial cross-sectional surveys of outpatient visits in the United States. METHODS: Medication use was assessed at each study visit and included medications in use prior to the visit and medications newly prescribed at the visit. Results were adjusted for survey weights and design factors to provide nationally representative estimates. RESULTS: Mean age was 75 +/−7 years, and 45% of visits occurred in primary care settings. Between 1999–2000 and 2009–10, the percent of clinic visits at which an opioid was used rose from 4.1% to 9.0% (P<.001). Although use of all major opioid classes increased, the largest contributor to increased use was hydrocodone-containing combination opioids, which rose from 1.1% to 3.5% of visits over the study period (P<.001). Growth in opioid use was observed across a wide range of patient and clinic characteristics, including in visits for musculoskeletal problems (10.7% of visits in 1999–00 to 17.0% in 2009–10, P<.001) and in visits for other reasons (2.8% to 7.3%, P<.001). CONCLUSIONS: Opioid use by older adults visiting clinics more than doubled between 1999–2010, and occurred across a wide range of patient characteristics and clinic settings

Should ultrasound guided percutaneous renal biopsy in children be done in a day care setting?

Percutaneous renal biopsy (PRB) is an important diagnostic tool in pediatric nephrology units. But controversy exists whether the procedure can be done in the day care setting. This study was done to document complications of PRB done with automated gun under continuous ultrasonographic guidance and to find whether the procedure can be undertaken as a day care procedure. Retrospective analysis of 67 PRBs is presented. A total of 44% (n = 30) minor and 12% (n = 8) major complications such as gross hematuria, perinephric hematoma, and hemodynamic instability were observed through the study period. All major and 90% of minor complications were detected within four hours in the current study. The procedure may be undertaken in the day care setting with strict pre and postprocedure monitoring up to eight hours in children with normal blood pressures, renal functions, hemoglobin concentrations, and coagulation parameters