Looking at the long-term graph comparing the English Drug Tariff with the average UK market price it does look as if there has been a profit squeeze on this product, primarily affecting Pharmacies, but this has resulted in a series of price bounces and shortages.
The price increases and subsequent price declines are very noticeable as a series of steps. This looks very much as if the cost of manufacturer has been increasing particularly in the period after 2016.
Although this is a very commonly used product, it could be that our international contract manufacturing partners are finding manufacture and supply more difficult and expensive than they did in the past. Certainly the period up to 2016 looks relatively stable, although the prices were declining throughout.
Geopolitical factors could also play a role here. The first price hike may be linked with Brexit, the second with Covid and the third with the Iran – Israel – USA war.
But it does seem to me that manufacturing and supply is costing more and that is pushing manufacturers and UK suppliers into unprofitability more frequently.