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Page 1: Dissolution Rates of Multivitamin Supplements in Different pH Environments

Poster Presentations 299

questionable. Reasonable alterations in the structure of thelaboratory should be considered to maximize its educa-tional benefit in future years.

Poster 68

Emphasis Techniques in Presentations: Effectivenessand Recall

Adam M. Preston, B.S., John R. Hayes, Ph.D., Yu-Chi Tai,Ph.D., and James E. Sheedy, O.D., PhD, Pacific UniversityCollege of Optometry, Forest Grove, Oregon

Background: The use of computer presentation software,such as Microsoft PowerPoint or Apple’s Keynote, iswidespread across every discipline. When used effectively,well-designed computer presentations are excellent aids tolectures and presentations. When poorly designed, com-puter presentations have the potential to lessen the valueof the presentation. To date, little has been studied onthe effectiveness of various typographical emphasis tech-niques used in such presentations. The purpose of thisstudy was to compare the effectiveness of common chro-matic and achromatic typographical emphasis techniquesused in computer presentations in terms of response timeand recall.Method: In the first of 2 experiments, subjects were pre-sented with a series of computer presentation slides inwhich one of 49 words was emphasized in one of the fol-lowing ways: bold, italic, underline, all capital letters, red,yellow, green, or blue text. The subject was asked to lo-cate and speak the emphasized target word, and a com-puter recorded the subjects’ reaction times. Theseconditions were tested across 3 different backgroundscommon to computer presentations: white, black, anddark blue. In the second experiment, subjects were askedto judge which of 2 words (only one had been empha-sized, but both had appeared only once) had occurredmost frequently in the first study.Results: Generally, chromatic emphasis techniques re-sulted in significantly faster reaction times than achro-matic emphasis techniques. Underline and italicemphasis techniques were consistently the least effectivemeans of emphasizing text across all background condi-tions. Using all capital letters elicited nearly the same re-action time regardless of the background and was thequickest achromatic emphasis response time on the mostbackgrounds. There was no significant difference in recallwhen analyzed for emphasis technique, background color,or chromaticity.Conclusion: Chromatic emphasis techniques result in fasterreaction times than achromatic ones, and all-capitalizationhas the fastest reaction times among achromatic emphasistechniques. The recall measure used in this study showedno differences among emphasis techniques. Further re-search is needed to determine optimum text/backgroundcombinations and to evaluate emphasis effectiveness oncognition and learning.

Poster 69

Dissolution Rates of Multivitamin Supplements inDifferent pH Environments

Kimberly Reed, O.D., and Storm R. Berman, NovaSoutheastern University, Ft. Lauderdale, Florida

Background: More than half of U.S. adults take a dailymultivitamin. Speculation abounds as to the necessity ofsupplementation and the preferred formulation ofsupplements if they are taken. Many experts believe thatsome multivitamin pills may be passed through the gastro-intestinal track largely undigested. Liquid vitamin supple-ments are designed to eliminate this potential problem.Still other experts believe that the acidity of the stomachneutralizes many nutrients that are contained in multivita-min pills. Delayed-release or extended release formulationsare designed to remain intact in the acidic pH of the stom-ach and to rapidly dissolve when encountering the more al-kaline environment of the small intestine. A potentialadditional benefit of delayed release tablets is that theyare often associated with fewer side effects; however, disso-lution and absorption within the small intestine is more dif-ficult to predict.Method: For this pilot study, a modified protocol based onthe U.S. Pharmacopeia (USP) simplified disintegrationtechnique was performed on several multivitamin pills,some of which were ‘‘rapid release’’ and others ‘‘delayed re-lease.’’ Pills were submerged in liquids with pH of 4.0 (trial1, to simulate the acidity of a stomach with food and/ordrink) and 2.0 (to approximate the acidity of an empty stom-ach), and were allowed to remain undisturbed at room tem-perature for 4 hours. Pills that were not indicated to be‘‘delayed release’’ or ‘‘extended release’’ formulations thatwere not dissolved within 60 minutes were considered fail-ures. Delayed release pills that did not dissolve after 4 hourswere gently bathed in tap water and then submerged in a liq-uid with pH of 8.0. These pills that did not dissolve within60 minutes of exposure to an alkaline environment wereconsidered failures using this protocol.Results: Some supplements failed to meet the dissolutiontimeframes indicated by the study protocol.Conclusion: The findings of this pilot study suggest thatthere is wide variability in commonly available multivita-min supplements with respect to dissolution, potentiallyaffecting absorption of nutrients.

Poster 70

Loteprednol Etabonate 0.2% in the Possible Treatmentof Dry Eye Syndrome

Candace Acord, O.D., Amanda Gonzales, O.D., and AlanG. McKee, M.S., O.D., NSU Oklahoma College ofOptometry, Tahlequah, Oklahoma

Background: Dry eye syndrome (DES) is a multifactorialdisease, the etiology, diagnosis, and management of whichare controversial. Tear film instability is the most widely