Thousand Oaks-based Amgen Inc. was among 24 pharmaceutical companies to participate in a blockchain project, titled MediLedger Network, which released its final report to the Food and Drug Administration on Friday. MediLedger is one of many pilot project proposals requested by the FDA to meet requirements of the Drug Supply Chain and Security Act, which is aimed at eliminating counterfeit pharmaceuticals. The blockchain network validates the authenticity of prescribed drugs through the supply chain, according to a statement from MediLedger, which has already been adopted by leaders in the industry for commercial use in tracking saleable drug returns. Starting this year, MediLedger will also provide services in contracting and chargeback processes in the pharmaceutical supply chain. Other companies that collaborated on the project include Walmart, Genentech, Pfizer, Sanofi and Eli Lilly.