There are a number of drugs that bind to plasma proteins. The weak acids and neutral drugs tend to bind to albumin (the range of drugs binding is the widest) which is one of the most common proteins found in blood plasma. This binding to the plasma proteins can play a significant role in determining drug distribution. This binding also plays a role in drug dynamics in that only the unbound or free drugs interact with the receptors and penetrate the cell membranes. Albumin along with others (i.e. lipoproteins, al-acid-glycoprotein) help with the binding process. As a result of this process, the drug that is bound is maintained in the blood stream while the unbound components are excreted or metabolize which creates the biological active part.
