Page1

Physical Appearance Determination of a Drug Substance Utilizing a Commercially Available Color Guide by Jennifer Alligood, Kimberly Lupo, Joe Cobb, Lauren McNeil, Ashley Dunning, Lauren Brock, Ken Jones, Credle Harris, Marjorie Misiura, David Nelson, Kym Rispress OBJECTIVE To develop a robust method to determine the physical color appearance of drug substance X that eliminates the subjective human bias for color selection. GENERAL BACKGROUND Physical appearance testing can be the most subjective but important tests performed on drug substances. The polymorphous form can provide information regarding the solid state of the material. The color can be an indication of purity and a means to identify contamination that occurred during the synthesis process. Typical testing involves viewing the material against a white background under specified lighting and reporting the color and form. Due to human bias observed during physical appearance testing of drug substance X, a commercially available color guide was utilized to develop a robust method to determine the physical appearance of said material. METHODOLOGY Materials Active Pharmaceutical Ingredient (API) X, Form A, Micronized, Supplied by Client Active Pharmaceutical Ingredient (API) X, Form B, Non-Micronized, Supplied by Client Active Pharmaceutical Ingredient (API) X, Form B, Micronized, Supplied by Client Pantone® Formula Guide, Solid Uncoated, Product Code GP1201 White Computer Paper Analytical Equipment Light Booth, Byko-Spectra, Part No. CG-6050 Olympus Model C2020Z Digital Camera Visual Method The following data were collected on several different lots and type of API X by three analysts using the visual method. The visual method consisted of viewing approximately 50 mg of API X placed on a white sheet of paper under laboratory lighting. The color of the API was recorded by each analyst without the knowledge of what the other analyst had recorded. There was some variability within each sample tested.

Page2

Table 1 – Visual Method Results

API X Lot API X Description Visual Method Results Precision

Analyst 1 Analyst 2 Analyst 3 Percentage

A Form B, Nonmicronized

Off-White Light Orange Off-white 67

B Form B, Micronized Light Orange Light Orange to Light Pink

Light Orange to Light Pink

67

C Form B, Micronized Light Brown Light Brown Light Orange 67

D Form A, Micronized Off-white w/ purple tint

Gray w/ purple tint

Off-white w/ purple tint

67

E Form A, Micronized Off-white w/ purple tint

Gray w/ purple tint

Off-white w/ purple tint

67

F Form B, Nonmicronized

Brown Dark Brown Brown 67

G Form B, Micronized Off-white Light Orange Off-white 67

Pantone Formula Guide The Pantone Formula Guide (Solid uncoated) is a commercially available compilation of color swatches. Each color swatch contains seven color shades represented by a numerical code (i.e. Color shade:4685U, Color swatch 55.5U). Refer to Figure 1 for a picture representation of the terms color shade and color shade. The color guide includes hundreds of color shades. Therefore, it was desirable to eliminate the color shades from the guide that was not needed for testing purposes but would give the analyst realistic color standards to compare the sample to.

Page3

Figure 1. Description of Terms Used

Color Shade Color Swatch

All of the samples that were tested per the visual method were compared to the all of color swatches contained in the Pantone® Formula Guide Solid Uncoated by two analysts. Two additional samples were also compared. The results shown below are reported as a color shade number followed by a color swatch code in parenthesis.

Page4

Table 2 – Initial Pantone® Method Results

API X Lot API X Description Pantone Initial Results

Analyst 1 Analyst 2 A Form B, Nonmicronized 4685U (55.5U) 4685U (55.5U)

B Form B, Micronized 489U (58U) 489U (58U)

C Form B, Micronized 4665U (55.5U) 4675U (55.5U)

D Form A, Micronized 434U (51U) 4755U (56.5U)

E Form A, Micronized 434U (51U) 4755U (56.5U)

F Form B, Nonmicronized 4645U (55.5U) 465U (55.5U)

G Form B, Micronized 4685U (55.5U) 4685U (55.5U)

H Form B, Micronized 4755U (56.5U) 4665U (55.5U)

I Form B, Micronized 465U (55U) 4645U (55.5U)

The color swatches that the analyst reported results from along with the color swatches that were in between the reported color swatches were cut into approximately 50 individual color shades. These shades were grouped into the following color categories by 6 analysts (3 that work with API X regularly and 3 that had never worked with API X): Off-White Pink Light Orange Light Purple Orange Light Brown Light Pink Brown Further Categorization Each analyst assigned the color shades to the corresponding color that they thought was the most representative of that shade. Each color category consisted of 7 to 10 shades. Due to practical use of the method, the number of shades in each category was decreased to no more than 5 shades. Each analyst categorized the 5 color shades to a corresponding color category. Using the Light Orange color category Figure 2 shows the progression of the color categorization.

Page5

Figure 2. Progression of Color Categorization for Light-Orange

Hundreds of Color Shades

Page6

The 3 color shades shown above are the 3 color shades that provide the widest range of the “Light Orange” color shades. The analyst will use these 3 color shades as a guide when determining if the reported color for API X is light orange. The following is a list of all of the color shades that were chosen for each color category. Each set of Pantone color shades are used as a guide to assist the analyst in determining the color of the API X. The Pantone Color Code is not reported. Table 3 – Pantone Color Categories as determined by Color Categorization Process

Color Category Pantone Code Orange 471U 473U 486U Light Orange 475U 488U 489U Brown 478U 4695U 464U 4645U Light Brown 4725U 467U 479U 465U Purple 490U 491U 4985U Light Purple 4995U 5005U 500U Pink 493U 494U 495U Light Pink 5035U 502U 496U Off White 4755U 481U 4685U

The same API X samples as in Table 1 were then compared to the above Pantone Color Categories to determine the reported color. As shown in Table 3, the results are much less subjective and show less variability than the visual method.

Page7

Table 4 – Pantone Appearance Results using the Color Categories

CONCLUSIONS The use of the developed Pantone Method for appearance testing of API X increased the precision of the method from 67% to 80 - 100%, and is thus considered to be more robust. The method variability decreased significantly.

API X Lot Pantone® Method Precision

Analyst 1 Analyst 2 Analyst 3 Analyst 4 Analyst 5 Percentage

A Off-white (4685U)

Off-white (4685U)

Off-white (4685U)

Light Brown (467U)

Light Orange (475U)

60

B Light Orange

(475U) Light Orange

(489U) Light Orange

(475U) Light Orange

(489U) Light Orange

(489U) 100

C Off-white (4685U)

Off-white (4685U)

Off-white (4685U)

Off-white (4685U)

Orange (473U)

80

D Off-white (4755U)

Off-white (4755U)

Off-white (4755U)

Off-white (481U)

Off-white (4755U)

100

E Off-white (4755U)

Off-white (4755U)

Off-white (4755U)

Off-white (4755U)

Off-white (4755U)

100

F Brown (465U)

Light Brown (464U)

Light Brown (465U)

Light Brown (465U)

Light Brown (465U)

80

G Off-white (4685U)

Off-white (4685U)

Off-white (4685U)

Light Brown (467U)

Off-white (4685U) 80