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Oral SyringeProduct Stability & Print DurabilityComparisonThe Comar Oral Syringe dispenser de-sign has proven to be the most stable product for ease of use and legibility when exposed to a series of dishwash-ing cycles. Competitive designs with silicone rubber seals require greater force to move the plunger in the syringe after the samples were exposed to repeated automatic dishwasher cycles and gradua-tion lines became difficult to read.

Oral Syringe Product Stability & Print Durability Comparison

Summary

The Comar oral syringe design (1mL, 3mL, 5mL, and 10mL) has proven to be the most stable product for ease of use and leg-ibility when exposed to a series of dishwashing cycles, based on the consistency of force required to push the plunger into the barrel and the durability of the artwork. Generally, oral syringe designs (Company B & Company C) utilizing silicone rubber seals require greater force to move the plunger in the barrel after the product was exposed to repeated automatic dishwasher cycles. The artwork and graduation line adhesion was also compromised, making them difficult to read.

Two-part oral syringe designs, (Comar, Company D & Com-pany E) relied on interference between the dimensions of the plunger and barrel to seal and did not exhibit the trend requiring increased force to depress the plunger after re-peated dishwashing cycles, as noted with the silicon rubber seal products. Significant greater data variance for Com-pany D and Company E in comparison to the Comar data was a concern and may point to greater part distortion when exposed to the dishwasher’s elevated temperatures.

BackgroundA similar functionality study was conducted in 2006 in which 10mL oral syringes from (same) Company B were compared to Comar products. In this earlier study, the oral syringes were subject to multiple washing cycles in a household dishwasher utilizing the dishwasher’s normal cycle with the temperature boost option and Cascade® granular detergent. The push force was measured following each dishwashing cycle to determine if lubrication degradation occurred. After the 14th dishwash-ing cycle in this 2006 study, the push force required for the competitor’s oral syringes began to rise. The testing concluded after 21 dishwashing cycles. See graph “2006 Force Test Com-parison” for data of this study.

ScopeThe intent of this study is to replicate the 2006 study and also expand the database by including additional competitors and oral syringe sizes. Products from four companies (Company A, Company B, Company C, and Company D) will be evaluated and compared against Comar products. The oral syringe sizes will include the original study’s 10mL sample group but will also be expanded to include 1mL, 3mL, and 5mL sample sets.

Procedure

The push force test was conducted on the oral syringes upon delivery to establish a baseline of the maximum force required to compress the plunger within the barrel. Following the base-line evaluation, the plungers were removed from the barrels and washed in a household automatic dishwasher through a “normal” cycle using a popular automatic dishwasher detergent (Finish® Powerball tabs). Following the dishwasher cycle, the sy-ringes were allowed to dry for 24 hours before being reassem-bled and tested again to determine the maximum compressive force. This routine was repeated until the samples reached 25 dishwashing cycles.

Results / Data - Push Force Test Data

1mL Oral SyringesThe force required to push the plunger into the barrel increased as the dishwashing cycles contin-ued for Company B and D 1mL samples. Oral syringe designs utilizing plungers with compliant (silicone) seals required the in-creased force.

In comparison; the Comar, Com-pany D, and Company E samples did not trend in this nature. Co-mar, Company D, and Company E samples rely on interference between the dimensions of the plunger and barrel to seal instead of a compliant seal. The values for these sample sets were relative-ly constant as the dishwashing cycles mounted. However, it was noted that Company D data was less consistent (as determined by coefficient of variance) of the three.

3mL Oral SyringesSimilar to the 1mL oral syringe results, Company B and Compa-ny C samples sets required more force to move the plungers. In this particular size, Company B climb was not as great as Compa-ny C (as shown by the differences in the trend line slopes). The seal designs were very similar so in-terference dimensions between the seal and barrel may have played a role.

Comar, Company D, and Compa-ny E were again similar. On aver-age, the Comar samples required the least amount of force to move the plungers. Additionally, in this syringe size, Company E was found to be less consistent for the duration of the test.

5mL Oral Syringe5mL oral syringes followed the same trends as the previous 1mL and 3mL results.

� Required force to move the plunger increased as dish-washing cycles continued for Company B and C samples. The compliant seal design of Company B and C are nearly identical, which likely explains the similarities in the data.

� As with the 3mL evaluation, the Comar samples required less force to compress the plunger within the barrel.

� Comar, Company D, and Company E samples did not require increased force as the test continued. However in this size category, the variance in dishwashing cycle to cycle data was significantly greater for Company D and E samples when compared to Comar.

10mL Oral SyringesCompany B 10mL oral syringe was the only sample to require increased force to compress the plunger within the barrel as the dishwashing cycles increased.

� This relates to the Company B seal design being similar to their seal design for 10mL, 5mL, and 3mL syringes.

In this size category, the Company C sample had a unique approach in that it utilized a compliant O-ring as the plunger seal. This design reduces the surface area of the seal and possibly gives it an opportunity to roll along the bar-rel surface, producing more con-sistent results than experienced with their 1mL, 3mL, and 5mL. No increase in the force requirement was realized as the test continued.

The force required for the Comar samples were below the values of any other manufacturer in this size category.

� The variance in dishwashing cycle to cycle data is greatest for Company D and E samples. This may be due to greater distortion of the parts when exposed to the elevated temperatures within the dish-washer.

Artwork Durability Results

Comar: no loss of print

Company E: slight color fading and heavy loss of print

Company D: heavy loss of print

Company C: no loss of print

Company B: spotty loss of print detail

Comar: no loss of print

Company E: slight fading

Company D: no loss of print

Company C: no loss of print

Company B: slight color fading

Comar: no loss of print

Company E: slight fading of color and loss of print at lower calibration lines

Company D: no loss of print

Company B: slight fading of color and minor spotty loss of print

Company C: no loss of print

Comar: very minor spotty loss of print

Company E: heavy loss of print, primarily at lower calibration lines

Company D: no loss of print

Company B: slight fading of color and very minor spotty loss of print

Company C: very slight fading of color and very minor spotty loss of print

1mL Print Evaluation - after 25 dishwashing cycles 3mL Print Evaluation - after 25 dishwashing cycles

5mL Print Evaluation - after 25 dishwashing cycles 10mL Print Evaluation - after 25 dishwashing cycles

Note: Competitors names and logos have been omitted from this document

ConclusionIn general, Comar samples required less force to compress the plunger within the barrel. Comar samples also produced data sets with the least variance, indicating that the samples were more stable or the design is adaptable to distortion during the duration of the test process.

Oral syringes, from Companies B and C, utilizing compliant material seals as part of the plunger generally require greater force to compress the plunger within the barrel as the sample is dish washed repeatedly. The likely cause of this is that the lu-bricant within the porous rubber seal eventually is eliminated and the friction between the seal and barrel increases. In this test, the force increase required was not significant. A few of the plunger seals began to bind but this only began to occur after the parts were washed at least 20 times. The binding also caused the rubber seals to separate from the plunger when the plunger was being withdrawn to ready the syringe for the next dishwashing cycle.

As a group, the 2-part oral dispenser designs did not show a trend similar to the samples using silicone rubber seal designs. However, as noted in the Results section, significant data vari-ation occurs for Company D and Company E samples; possibly caused by greater part distortion when exposed to the dish-washer’s elevated temperatures.

In regard to artwork durability, overall Comar and Company C samples maintained the color depth and detail of the print better than Company B, Company D, and Company E samples.

� Overall, Company E samples had the largest problem maintaining the artwork appearance. A significant loss of the print was evident on the 1mL and 10mL samples.

� Company B artwork color faded slightly and also lost print detail in spots, suggesting the color was not uniformly bonded to the surface.

� Company D sample results were very good for the 3mL, 5mL, and 10mL. However, the 1mL samples lost a signif-icant amount of the print detail, suggesting that their process is not consistent across the entire range of syringe sizes.

Comparing this data to the original 2006 data set does show some similarities but also a marked difference:

� Oral syringes utilizing compliant rubber seals require greater force to compress the plunger into the barrel as the sample is dish washed repeatedly; whereas syringes relying on interference between the plunger and barrel do not.

� In this test, the severity of the force increase was not noted as it was in the 2006 study. This could be due to a number of factors, including: dishwasher detergent chem-istry, water chemistry/softness, water temperature, seal and lubricant chemistry, etc. These factors play a role in breakdown, sequestering, and removal of materials during the automatic dishwashing process.

AppendixForce Testing Procedure

Each part of the oral syringes within a volume category were marked so that the matched pair of barrel and plunger are linked for the duration of the study (i.e. 1 on the barrel and plunger would represent sample 1).

Oral syringe standards for each sample set have been created to set the top and bottom limit switches on the test stand. The intent of the standards is to speed the test setup when chang-ing from one sample set to the next and to also insure that the plungers are not completely compressed into the bottom of the barrel of the syringe.

Pull the plunger within the standard oral syringe until the black line shows above the barrel edge. With the oral syringe stan-dard in the appropriate fixture, raise or lower the force gauge until platen of the force gauge is just above the plunger top. Lock the top limit switch in this position.

Then, lower the force gauge until the red line on the standard oral syringe is just above the barrel edge. Lock the bottom limit switch at this position.

Place the plungers into the barrels for the sample sets. Push the plungers in until the plunger is at the volume indicator for the appropriate test set (i.e. 10mL indication line for 10mL sy-ringes). [Company E syringes may have greater volumes. Push plunger to sample set designation].

Next, place sample into the appropriate fixture being sure to seat the sample to the bottom of the fixture. (Special Note: 5mL syringes from Company B, Company C, Company D, and Com-pany E utilized the 10mL fixture with an O-ring placed around the syringe barrel to stabilize the syringe within the fixture.)

Check the force gauge to insure that the units of measure are in lbs. and that the maximum compressive force will be displayed during the test. (Refer to the force gauge manual for informa-tion on how to change these settings.)

Rotate the sample under the force gauge platen and reset the force gauge by pressing the RESET button, the force gauge dis-play should show “0.00”. Activate the test by pushing the test stand START/STOP toggle to the DOWN position. The test stand will move the force gauge down until the lower limit switch is contacted at which time the test stand will rise rapidly to the start position. The display will show the maximum force at-tained while pressing the plunger into the barrel. Record this value for the sample. Remove the sample and repeat these steps for the additional samples.

Addendum - Volumetric Evaluation

SummaryThe measurement of calibration line positions was conducted on new and dishwashed 1mL and 10mL oral syringes. This study was conducted to determine if the dishwashing environment distorted the oral syringe barrels enough to impact the volu-metric accuracy of the products. Comar product results were compared against results from the same brands as the original Product Stability & Print Durability Comparison study. The re-sults do not conclusively indicate that distortion occurred at a level that would impact the calibration line positions. How-ever, variation in line position for all competitive products was greater than that of the Comar products.

BackgroundDuring the Product Stability & Print Durability Comparison study, significant variation in the force was required to com-press the plunger into the barrel for the Company D and E sam-ples. Since this oral syringes are similar to the Comar design, in that the designs are 2-part construction (without a rubber seal), it was conjectured that the variation was due to part distortion instead of loss of lubrication associated with the rubber seal. If part distortion was occurring, there may also be an impact on the oral syringe’s ability to maintain volumetric accuracy.

ScopeThe intent of the addendum to the Oral Syringe Comparison Study was to determine the impact of the dishwasher cycles on the oral syringes’ capability to maintain volumetric accu-racy. The belief is that increased push force required to push the plunger into the barrel could be an indication that the oral syringe barrel has distorted to a point that increases the inter-ference between the barrel and plunger. Through the measure-ment of the calibration line positions, we are attempting to de-termine whether distortion of the parts occurred.

ProcedureThe push force test was conducted on the oral syringes upon delivery to establish a baseline of the maximum force required to compress the plunger within the barrel. Following the base-line evaluation, the plungers were removed from the barrels and washed in a household automatic dishwasher through a “normal” cycle using a popular automatic dishwasher detergent (Finish® Powerball tabs). Following the dishwasher cycle, the sy-ringes were allowed to dry for 24 hours before being reassem-bled and tested again to determine the maximum compressive force. This routine was repeated until the samples reached 25 dishwashing cycles.

10mL Oral Syringes

The calibration line proximity results for the 10mL oral syringes are similar to the 1mL results. Except for Company D sample groups, the lack of difference in position and range of position for the 1mL and 10mL calibration lines of the new and washed samples indicates that little distortion of the barrels has oc-curred. This data is illustrated in following Charts 3 and 4.

Company D products would indicate that exposure to the dish-washer environment altered the samples; however, another factor could play a role in this particular sample group. Ad-ditional Company D samples were ordered and evaluated to provide the New (unwashed) samples for this volumetric eval-uation. Therefore, the differences could indicate an issue with print registration control between production lots rather than actual impact from the dishwashing.

Results / Data1mL Oral Syringes

Evaluating the 1mL oral syringes, the calibration line proximity does not appear to have altered due to the dishwashing cycles. The fol-lowing charts (Chart 1 and Chart 2) illustrate the positions of the 0.1mL and 1mL calibration lines on the 1mL oral syringes for the new and washed sample groups. The position of the calibration lines and the range of the positions for each manufacturer are con-sistent between the new and washed samples for each manufac-turer.

It is evident within the charts that the Company C 1mL product has the largest variation (new or washed) whereas the Comar product has the least when you evaluate the variance of the calibration line positions. The variance values for these sample groups are noted on the charts.

Chart 1 Chart 2

Chart 3 Chart 4

The variances for all of sample groups were calculated. These values provide a reference to understand the scatter of the data points within each sample set; the greater the variance, the greater the scatter in the data. It shows that the position of the lines for the Comar oral syringes, whether new or washed, is more repeatable than for the other manufacturers.

Variance

New Oral Dispensers

1mL Product 10mL Product

0.1mL Line

1mL Line

1mL Line

10mL Line

Variance Total

Comar 3.2E-06 6.8E-06 4.4E-06 5.5E-06 2.0E-05

Company D 3.0E-05 1.4E-05 7.9E-06 1.1E-05 6.3E-05

Company B 3.2E-05 2.8E-05 6.7E-06 6.9E-06 7.3E-05

Company E 6.8E-06 1.4E-05 2.8E-05 3.7E-05 8.6E-05

Company C 4.1E-05 6.3E-05 7.3E-06 7.3E-06 1.2E-04

Washed Oral Dispensers

1mL Product 10mL Product

0.1mL Line

1mL Line

1mL Line

10mL Line

Variance Total

Comar 7.9E-06 1.0E-05 4.6E-06 2.2E-06 2.5E-05

Company C 1.1E-05 1.7E-05 9.1E-06 2.0E-05 5.6E-05

Company B 1.5E-05 1.8E-05 4.8E-05 4.0E-05 1.2E-04

Company E 8.4E-05 6.4E-05 1.1E-05 1.7E-05 1.8E-04

Company D 1.5E-05 1.5E-05 2.6E-04 1.6E-04 4.5E-04

Best to Worst ->

Best to Worst ->

ConclusionThis method of evaluation did not determine that the oral sy-ringes distorted to a degree severe enough to alter the relative positions of the calibration lines on the barrel. It is likely that the increased force required was due to loss of lubricity and possi-bly distortion; but the distortion being related to the circularity of the barrel. The barrels may have become more ovalized caus-ing the required increase in push force but not impacting the calibration line position.

However, the variation of the calibration line positions on new and washed samples for some of the manufacturers was sig-nificantly greater than the Comar product. This will impact the capability to maintain volumetric accuracy between the man-ufacturer’s samples.

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