See the DrugPatentWatch profile for lipitor

The difference in generic Lipitor strengths compared to brand Lipitor can be attributed to several factors, primarily related to the drug's patent, manufacturing, and regulatory approval processes.

Firstly, when a new drug is developed, the company that creates it is granted a patent, providing them with exclusive rights to produce and sell the drug for a certain period, typically 20 years [1]. During this time, the drug is sold under a brand name, and the company can set its price and determine the available strengths. Once the patent expires, other manufacturers can produce and sell generic versions of the drug.

In the case of Lipitor, the brand name for atorvastatin, the patent expired in 2011 in the United States [2]. After the patent expiration, generic manufacturers were allowed to produce and sell atorvastatin, which led to variations in the available strengths.

Generic manufacturers may choose to produce specific strengths based on market demand, manufacturing capabilities, and regulatory requirements [3]. The U.S. Food and Drug Administration (FDA) requires that generic drugs have the same active ingredient, strength, dosage form, and route of administration as the brand-name drug [4]. However, there can be minor differences in inactive ingredients, such as fillers, binders, and coloring agents, which may lead to slight variations in the size, shape, or color of the generic drug compared to the brand-name drug [5].

In summary, the differences in generic Lipitor strengths compared to brand Lipitor can be attributed to the patent expiration, market demand, manufacturing capabilities, and regulatory requirements for generic drugs.

Sources:

1. "Patents and Exclusivity." U.S. Food and Drug Administration. <https://www.fda.gov/drugs/development-approval-process-drugs/patents-and-exclusivity>.
2. "Lipitor (atorvastatin) Tablets." Pfizer. <https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/021088s063lbl.pdf>.
3. "Generic Drug Facts." U.S. Food and Drug Administration. <https://www.fda.gov/drugs/understanding-generic-drugs/generic-drug-facts>.
4. "Approved Drug Products with Therapeutic Equivalence Evaluations 31st Edition (Orange Book)." U.S. Food and Drug Administration. <https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book>.
5. "Generic Competition and Drug Prices." Congressional Research Service. <https://crsreports.congress.gov/product/pdf/R/R41458>.
6. "Lipitor (atorvastatin) Tablets." DrugPatentWatch. <https://www.drugpatentwatch.com/patent/lipitor-atorvastatin-tablets/>.