A Comparison of the Physical Properties of Some Commercial Aspirin Tablets Elaine Armstrong STEP

Objective Compare physical properties of commercially available aspirin tablets

Methods

Testing of Aspirin Tablets Friability Hardness Thickness Disintegration Weight Variation Dissolution

Friability Testing USP test to determine how well tablets will stand up to coating, packaging, shipping, and other processing conditions –Ten tablets were dusted and weighed on the analytical balance –The tablets were placed in the section 1 of the drum of the friability tester and rotated 100 times –The tablets were re-dusted and re-weighed –According to USP, the tablets should not lose more than 1% of their total weight

Friability Testing

Hardness Determine the crushing strength of the tablets –Using forceps, the 10 tablets were individually placed between the platens of the hardness tester –The test button was pushed and the instrument gave a visual reading of tablet hardness

Thickness Determines the tablet thickness –Ten tablets were dusted and using forceps were individually placed between the calipers of the thickness tester –The instrument gave a visual reading of tablet thickness

Hardness/Thickness Testing

Weight Variation Shows the uniformity of tablet weights –Ten tablets were dusted and weighed using the analytical balance –The mean tablet weight and standard deviation was calculated –According to the USP, the requirements for uniformity are met if each individual tablet is within 85% to 115% of the mean

Weight Variation Testing

Disintegration USP test to determine the time required for tablets to disintegrate –A 900 mL beaker was filled with 37±2º C water –Six tablets were placed into the basket-rack assembly and connected to the disintegration apparatus –The apparatus and the timer were started simultaneously and the time required for the last tablet to disintegrate was recorded

Disintegration Testing

Dissolution The purpose of dissolution testing is to see how much of the tablet goes into solution after a given time period

Preparing the 0.05M Acetate Buffer Sodium Acetate Trihydrate was weighed and placed into a 2000 mL volumetric flask Glacial Acetic Acid was then pipeted into the flask The flask was filled with water up to the mark The resulting solution was thoroughly mixed and the pH was determined using the pH meter 500 mL of buffer was measured three times and added into three round bottom dissolution vessels

Dissolution Testing The vessels were added to a circulating water bath maintained at 37ºC and allowed to equilibrate Once the desired temperature was obtained, the tablets were added to the mesh cylindrical baskets and the baskets were lowered into the vessels and rotated at 50 rpm for 30 minutes.

Dissolution Testing

Dissolution Analysis A sample was removed from each vessel using a syringe and then filtered with a 0.45  m nylon filter The sample was diluted with buffer and the concentration was determined by measuring the absorption at 265 nm using an Ultrospec 3300 pro UV/Visible Spectrophotometer and comparing to a Standard Curve

Standard Curve

Dissolution Analysis

Results

Lite Coat Aspirin(Coats Pharmacy) Distributed by Quality Choice NOVI Michigan Cost: $4.19 Expires:9-04 Lot #: P25814

Lite Coat Tablet Results Friability (percent loss)0.34% Weighing Variation (average/st. dev.) 0.98±0.18 g Hardness (average/st. dev.) 13.56±1.3 SC Thickness (average/st. dev.) 0.169±0.002 in Disintegration (time)21 sec Dissolution (average/st. dev.) 247.5±21 mg

Equate (Wal-Mart Brand) Aspirin Tablets Manufactured by Perrigo Co. Alegan, MI Cost: $0.97 Expires: Lot #: 20E0033

Equate Tablet Results Friability (percent loss)-0.14% Weight Variation (average/st. dev.) 0.94±0.02 g Hardness (average/st. dev.) 10.12±1.04 SC Thickness (average/st. dev.) 0.17±0.001 in Disintegration (time)17 sec Dissolution312.1±14.8 mg

CVS Brand Aspirin Distributed by CVS Pharmacy, Inc. Woonsocket,RI Cost: $1.99 Expires: 1-04 Lot #: 2DE0280

CVS Brand Tablet Results Friability (percent loss)0.42% Weight Variation (average/st. dev.) 0.94±.02 g Hardness (average/st. dev.) 9.5±1.01 SC Thickness (average/st. dev.) 0.17±0.001 in Disintegration (time)17 sec Dissolution263.7±2.4 mg

Medical Center (Bookstore) Aspirin Distributed by Diamond Products Seffner,FL Cost: $1.09 Expires: 4-02 Lot #: 1639

Medical Center Tablet Results Friablility (percent loss)0.9% Weight Variation (average/st. dev.) 0.92±0.01 g Hardness (average/st. dev.) 14.14±2.96 SC Thickness (average/st. dev.) 0.17±0.03 in Disintegration (time)8 min 55 sec Dissolution (average/st. dev.) ±16.6 mg

Kroger Brand Aspirin Distributed by the Kroger Co. Cincinnati,Ohio Cost: $1.99 Expires: 8-03 Lot #: 1LE0732

Kroger Brand Tablets Results Friablility (percent loss)0.01% Weight Variation (average/st. dev.) 0.94±0.01 g Hardness (average/st. dev.) 11.18±1.15 SC Thickness (average/st. dev.) 0.171±0.002 in Disintegration (time)18 sec Dissolution (average/st. dev.) 259.9±2.8 mg

Target Brand Aspirin Distributed by the Target Corporation Minneapolis,MN Cost: $2.64 Expires: 1-04 Lot #: 2CE0334

Target Brand Tablets Results Friablility (percent loss)0.12% Weight Variation (average/st. dev.) 0.94±0.01 g Hardness (average/st. dev.) 8.68±1.06 SC Thickness (average/st. dev.) 0.172±0.002 in Disintegration (time)19 sec Dissolution (average/st. dev.) 251.4±6.4 mg

American Fare (Kmart) Brand Aspirin Made for Kmart Corporation Troy, Michigan Cost: $1.99 Expires: 8-04 Lot #: P25463

American Fare Tablets Results Friablility (percent loss)0.39% Weight Variation (average/st. dev.) 0.93±0.01 g Hardness (average/st. dev.) 13.81±1.9 SC Thickness (average/st. dev.) 0.171±0.001 in Disintegration (time)26 sec Dissolution (average/st. dev.) 270±5.6 mg

Bayer Aspirin Distributed by the Bayer Corporation Morristown,NJ Cost:$3.99 Expires: 1-04 Lot #: B

Bayer Tablets Results Friability (percent loss) 0.01% Weight Variation (average/st. dev.) 0.95±0.01 g Hardness (average/st. dev.) 9.83±0.91 SC Thickness (average/st. dev.) 0.174±0.001 in Disintegration (time)18 sec Dissolution (average/st. dev.) 254.1±6 mg

Pharmacy School Aspirin Packaged by Paddock Laboratories Inc. Minneapolis,MN Expired:12-97 Lot #: 5G6529

Pharmacy School Tablets Results Friability (percent loss)0.93% Weight Variation (average/st. dev.) 0.93±0.01 g Hardness (average/st. dev.) 16.15±1.41 SC Thickness (average/st. dev.) 0.171±0.002 in Disintegration (time)19 sec Dissolution (average/st. dev.) 280.1±18.1 mg

Overall Results Friability (% Loss) Weight Variation (g) Hardness (SC) Thickness (in) Disintegration (sec) Disso- lution (mg) Lite Coat Equate CVS Bookstore Kroger Target K-Mart Bayer Pharmacy School

Conclusions

Summary The tablets all met USP standards for friability The tablets displayed uniformity in terms of hardness, thickness, and weight variation With the exception of the tablets obtained from the bookstore, all tablets disintegrated within 30 seconds Five of the nine lots tested passed USP standards for dissolution