The phrase "although it was initially" is correct and usable in written English.
You can use it to introduce a contrast or a change in situation that occurred after an initial state or condition.
Example: "Although it was initially difficult to adapt to the new software, I eventually found it quite user-friendly."
Alternatives: "even though it was first" or "despite being initially".
Nevertheless, although it was initially planned as a single centre study, initial recruitment data indicates that the response rate is lower than anticipated and further departments of neurophysiology within the UK will be included subject to local research governance approval.
Although it was initially used exclusively to combat malaria, its use quickly spread to agriculture.
Douglas was diagnosed with tongue cancer in 2010, although it was initially reported as throat cancer.
Although it was initially successful, this attempt failed and the troops were withdrawn a year later.
Although it was initially considered too radical, it is now seen as an iconic design.
Although it was initially feared that this might delay the schedule, everything is back on course now.
Although it was initially dismissed as a novelty, punk has survived for a quarter-century by stubbornly retaining its structure even as its meanings have been transformed.
Although it was initially one of five Japanese cities under consideration by US president Harry Truman and his advisers, there are compelling reasons why the Americans targeted Hiroshima.
Although it was initially driven by food, the rise in prices is now broad, and, as the RBI called it in today's statement, "stubborn".
The reason it's worse is that the solution he endorsed as governor of Massachusetts, the individual mandate, although it was initially a Republican idea, is no longer politically permissible in the Republican Party.
Although it was initially decried by critics as a brutal blood sport without rules, MMA gradually shed its no-holds-barred image and emerged as one of the world's fastest-growing spectator sports in the early 21st century.
