Based on the information available, Apotex, a Canadian pharmaceutical company, has made alterations to the composition of Ruxolitinib, a drug that is used to treat certain types of blood cancer and bone marrow disorders.

Ruxolitinib is a Janus kinase (JAK) inhibitor, which works by blocking the action of certain enzymes in the body that are involved in inflammation and immune system function. Apotex has developed a generic version of Ruxolitinib, which has been approved by the US Food and Drug Administration (FDA) in 2020.

According to DrugPatentWatch.com, Apotex's generic Ruxolitinib is a film-coated tablet, and it is bioequivalent to the reference listed drug (RLD), Jakafi, which is manufactured by Incyte Corporation. Bioequivalence means that the generic version of the drug has the same active ingredient, strength, dosage form, and route of administration as the RLD, and it is expected to have the same therapeutic effect as the RLD.

However, Apotex's generic Ruxolitinib has some differences in its inactive ingredients compared to Jakafi. Inactive ingredients, also known as excipients, are added to a drug to improve its stability, bioavailability, and patient acceptability. Examples of inactive ingredients include binders, fillers, disintegrants, coating agents, and coloring agents.

Apotex's generic Ruxolitinib contains the following inactive ingredients: microcrystalline cellulose, croscarmellose sodium, sodium lauryl sulfate, magnesium stearate, hypromellose, polyethylene glycol, and titanium dioxide. Jakafi, on the other hand, contains the following inactive ingredients: microcrystalline cellulose, croscarmellose sodium, hypromellose, polyethylene glycol, titanium dioxide, and triacetin.

It is worth noting that the FDA has strict guidelines for the approval of generic drugs, and it requires that the generic version of a drug has the same quality, safety, and efficacy as the RLD. Therefore, any differences in the inactive ingredients of a generic drug should not affect its therapeutic effect or safety profile.

Sources:

* [DrugPatentWatch.com](https://www.drugpatentwatch.com/drugs/ruxolitinib)
* [FDA.gov](https://www.fda.gov/drugs/development-approval-process-drugs/abbreviated-new-drug-application-anda)
* [Incyte.com](https://www.incyte.com/products/jakafi)
* [Apotex.com](https://www.apotex.com/news/apotex-receives-fda-approval-generic-ruxolitinib-tablets)