The two men and two women are charged under the Misuse of Drugs Act in connection with the seizure of the prescribed drugs in Edinburgh.
On October 5 police found about 22,500 diazepam tablets in a flat in the city's Murrayburn Gardens. Around £2500 in cash was also found. A 42-year-old man was charged in connection with drug offences, along with a woman, 41. Both have appeared in court and the man was remanded in custody, police said.
Another search of a property in Broughton Road yesterday saw police seize a further 40,000 diazepam pills. A man, 42, and 26-year-old woman are set to appear at Edinburgh Sheriff Court in connection with the haul.
The total value of the diazepam from both raids is around £62,500, police said.