Isolation of the Active Ingredient in an Analgesic Drug

Isolation of the active ingredient in an Analgesic Drug from extraction, filtration and melting point.

Chm237

Abstract:

Acetaminaphen was crushed then extracted for the active ingredient by mixing it with methanol. Then separated from the binders by centrifugation and a filtration technique using a Pasteur pipet packed with alumina. The remaining solvent was then evaporated to yield the solid analgesic(.2295g, 45.9% yield) which was collected by filtration and tested for the purity of the drug by the melting point determination. The melting point was (135-142 C) compared to the literature melting point values for acetaminophen (169-171 C) the lower melting point show that their were still impurities in the isolated ingredient.

Procedure:

The acetaminophen (0.5395g) was crushed and added to a conical vial and was mixed with 2ml of methanol then shaken and let to sit till the undissolved particles settled to the bottom and transferred the liquid into a centrifuge tube using a filter-tip pipet. Repeating the process with an additional 2mL of methanol. The solvent was then centrifuged for 3 minutes until the mixture had settled into a supernatant liquid layer and a solid layer. Then in a prepared alumina column with 0.5 mL g of alumina 2mL of methanol was added to column and then the solution containing the drug. Followed by 1 mL of methanol through the top of the alumina. Half of the solution was then transferred into a small container. The remaining solvent was then evaporated in a preheated 50 C water bath and gentle air stream until 1 mL was left. The remaining solvent was then added and evaporated completely.

Then cooled to room temperature where crystals slowly formed. Then placed into an ice-bath where more white crystals started forming. After cooling for 10 min at 0 C the crystals were then scooped and placed onto a Hirsch funnel for 10 min. The dried sample was then weighed (.2295g, 45.9% yield) and compared to the value weight of the active ingredient. Afterwards the crystals were tested for the melting point (135-142 C)

Results and Calculations (10 points for section total)

Brand name of starting drug

Nonasprin pain reliever

Name of active ingredient (from now on called “drug”)

Acetaminophen

Literature melting point of “drug”

169-171 C

Melting point of isolated “drug”

133-145 C

135-142 C

Starting mass of “drug”

.5395 g

Final mass of isolated “drug”

.2295 g

Percent recovery

45.9 %

Show complete calculations for percent recovery (3 pts)

Discussion and Conclusions (10 points)

What does the melting point range of the isolated “drug” indicate about its purity and