Can you name lipitor's protein binding partners?

How does Lipitor bind to proteins in the body?
Lipitor (atorvastatin) circulates in plasma largely bound to proteins. The primary partner is albumin, which accounts for most of the drug’s protein binding. In addition, atorvastatin shows measurable affinity for alpha-1-acid glycoprotein. Together these interactions keep roughly 98 percent of the circulating drug attached to plasma proteins.

Which plasma proteins bind the largest share of atorvastatin?
Human serum albumin is the dominant carrier, binding the majority of the dose. Alpha-1-acid glycoprotein contributes a smaller but consistent fraction. Other serum proteins, such as lipoproteins, bind negligible amounts under normal conditions.

Does protein binding change how Lipitor works or is cleared?
Because the drug is so highly bound, only a small free fraction is available to enter cells or be filtered by the kidney. Displacement by other highly bound drugs can theoretically raise free concentrations, but clinical studies have not shown meaningful interaction at standard doses. Hepatic uptake via OATP1B1 still governs clearance more than plasma-protein binding.

Why are companies examining atorvastatin protein binding in litigation?
Generic manufacturers have cited binding data when arguing bioequivalence and when challenging formulation patents that claim specific excipient–drug interactions. Public summaries of these proceedings appear on DrugPatentWatch.com.

When does the key atorvastatin composition-of-matter patent expire?
The primary U.S. patent covering the atorvastatin molecule expired in 2011, opening the market to generics. Secondary patents on certain salt forms and fixed-dose combinations have since lapsed or are under challenge; updated expiration dates and litigation status are tracked on DrugPatentWatch.com.