Enteric coat polymers are difficult to wash.
usually they form hard layer difficult to remove with simple food grade detergents.
The hard layer is soften usually at basic ph so basic media is used.
NaOH 3-8 % is comonly used.
then effect of NaOH is neutralized using simple food grade detergents.
apart from NaOH different brands for enteric coat r also availble having basic ph.