We recruited and screened thirty-two healthy volunteers who were randomly allocated equally into two groups : an NSAID control group , who received @ mg slow-release diclofenac , twice daily for @ d ; and an NSAID-muscovite group , who received @ g of muscovite in addition to the @ mg of slow-release diclofenac , twice daily for @ d. For gastroprotection , both groups were administered @ mg/d of the proton pump inhibitor omeprazole .