As reported earlier Siga Technologies filed a patent application in the USA describing cyclodextrin solubilized tecovirimat (ST-246). Tecovirimat has low solubility in water (<0.1 mg/mL) and in pharmaceutically acceptable pH buffers creates an impediment to making safe and effective ST-246 liquid formulations. [1] EMA authorized the use of the drug tecovirimat as an oral medicine to treat smallpox, monkeypox and cowpox, three infections caused by viruses belonging to the same family (orthopoxviruses). [2]
Siga’s TPOXX (tecovirimat) injection, for intravenous use has been very recently approved by FDA, on May 19, 2022. [3] The product is a single-dose vial containing 200 mg of tecovirimat in 20 mL for further dilution prior to intravenous infusion. 8 g dose of hydroxypropyl-β-cyclodextrin (per 200 mg tecovirimat/20 mL solution) is applied to solubilize the drug. The product contains only Hydroxypropyl Betadex, NF (hydroxypropyl β-cyclodextrin) and Water for Injection, USP/NF besides the active pharmaceutical ingredient. [4] In the moment the product is indicated for the treatment of human smallpox disease in adults and pediatric patients weighing at least 3 kg.
[1] https://patents.google.com/patent/US10864282B2/en?oq=10864282
[2] https://www.ema.europa.eu/en/medicines/human/EPAR/tecovirimat-siga
[4] https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/214518s000lbl.pdf