<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
Skip Navigation


Introduces structure and formation of lipid bilayers in cells.

Atoms Practice
Practice Phospholipids
Practice Now
Avoiding the Needle

Avoiding the Needle

Nobody enjoys getting a shot. The idea of having a needle stuck in you is unpleasant at best. Some people have such a fear of shots that they pass out before they are even injected. However, many drugs have to be injected because the digestive tract would destroy them before they got into the system. What if there was a way to get these drugs orally and not have the body destroy them before they reached the site where they were needed?

Amazing But True

  • The stomach produces HCl to aid in digestion of food. This acid freely releases protons to react with whatever it comes in contact with. When a person takes an aspirin, the parent compound (acetylsalicylic acid) is hydrolyzed by stomach acid to form salicylic acid (the active ingredient). The acid derivative is used because the salicylic acid itself was strongly irritating to the stomach. HCl is a strong acid and will inactivate a number of drugs.
  • The stomach may sometimes regurgitate acid and cause pain in the chest area. This is known as heartburn and is often associated with the consumption of highly acidic foods


  • One new approach to drug administration that is being exploredis the liposome. This system consists of a phospholipid bilayer membrane which has the water-soluble phosphate group on the outside and inside of the bilayer. The water-insoluble fatty acid portion is in the interior of the bilayer. The empty interior can have a water-soluble drug incorporated into it. Lipid-soluble materials can be inserted into the fatty acid segment of the liposome.
  • Although these techniques have not yet been adapted for human use, animal studies look very promising. A variety of techniques are being explored for oral administration, inhalation, and transdermal (across the skin) absorption. The different approaches all avoid drug contact with the harsh stomach acid and with the various digestive enzymes in the small intestine.
  • Watch a video about liposomes at the link below: http://www.youtube.com/watch?v=04SP8Tw3htE

Explore More

Use the links below to learn more about liposomes. Then answer the following questions.

  1. Are liposomes natural or artificially made?
  2. Who first developed the liposome and when?
  3. What is the hydrophobic part of a liposome?
  4. What is one use for liposomes?

Image Attributions

Explore More

Sign in to explore more, including practice questions and solutions for Arrhenius Acids.


Please wait...
Please wait...

Original text