Darvon is a brand-name prescription drug developed by the pharmaceutical company Eli Lilly and approved in 1957 by the FDA to manage the symptoms of mild to moderate acute pain. The active ingredient in Darvon is propoxyphene HCL, a centrally acting narcotic classified as an opioid, according to Drugs.com. RxList.com notes that Darvon is formulated as yellow oval tablets, and is only available in 65 mg dosages.
Propoxyphene HCL
Propoxyphene was initially introduced to the market as propoxyphene HCL, although after the patent expired, a “safer, weaker” version that could not be injected was approved in 1972 as propoxyphene napsylate, according to the "Dictionary of Pharmaceutical Medicine." The Darvon product that contains this variety is known as Darvon-N. DrugLib.com notes that propoxyphene HCL is a mild narcotic analgesic that interacts with opioid receptors, and is used primarily for pain control, but also as a local anesthetic and cough medicine.
Binding, Filling and Disintegrating Agents
According to DailyMed, Darvon contains corn starch and gelatin as binders and fillers. Binders act to hold the ingredients together such that tablets can be formed with the appropriate force. The corn starch also acts as a disintegrant which, according to the "Dictionary of Pharmaceutical Medicine," expands and dissolves when wet, causing the tablet to disintegrate in the lower gut and release propoxyphene HCL for absorption. The cellulose/gelatin compounds also act as fillers, which make the tablet larger, making it practical for manufacturing and convenient for users to handle. Fillers are chemically inert, compatible with other ingredients, water soluble, colorless and tasteless.
Lubricating, Stabilizing and Mixing Agents
Magnesium stearate is another inactive ingredient in Darvon, and acts as a lubricant and stabilizer in the compounding process of drug manufacturing. Magnesium stearate also has the ability to combine with the other ingredients and help mix them together evenly, according to the "Dictionary of Pharmaceutical Medicine." Silicon dioxide is a common food additive and also found in Darvon, and acts as a lubricant and absorber of water. According to the "Dictionary of Pharmaceutical Medicine," lubricants assist with the flow of powdered ingredients through production and help prevent them from sticking to the manufacturing equipment.
Coloring Agents and Coatings
According to DailyMed, Darvon 65 mg tablets contain FD & C red #33 and FD & C yellow #6 edible food dyes. Titanium dioxide is another ingredient added for coloring because of its ability to provide brightness, shine and opacity to pharmaceutical tablets and pills. Finally, the gelatin found in the tablets forms part of the covering and can aid in the process of swallowing.
References
- “Dictionary of Pharmaceutical Medicine”; G. Nahler, et al.; 2009
- Drugs.com: Darvon
- RxList.com: Darvon
- DrugLib.com: Darvon / propoxyphene
- DailyMed: Darvon Ingredients
