Pharmaceutical quality of seven brands of diclofenac tablet on the Saudi market

OBJECTIVE: We previously reported the pharmaceutical quality of eight brands of 50 mg enteric-coated diclofenac sodium tablet available on the Saudi market. Here, we assess the quality of reference (R1) and four generic (G1–G4) brands of 50 mg immediate-release diclofenac potassium tablet and of reference (R2) and generic (G5) brands of 100 mg sustained-release diclofenac sodium tablet. RESULTS: Weight variation (range as % difference from mean), active substance content (mean (SD) as % difference from label), breaking force [mean (SD)], and friability (as % weight loss) were 95–104% and 99–102%, 100.9% (3.4%) and 105.6 (4.2%), 12.2 (1.3) and 12.9 (1.8) kg, and 0.0014% and 0.0012%, for R1 and R2, respectively. For G1-G5, they were ≤ ± 2%, 98.8% (2.7%) to 109.2% (3.8%), 6.4 (0.6) to 13.3 (1.0) kg, and 0.0007% to 0.0261%, respectively. R1 and G1-G4 disintegrated within 04:50–17:20 min: seconds and released a mean of 89–100% of label active substance content by 60 min in buffer (pH 6.8). R2 and G5 did not disintegrate or dissolve in 0.1 N HCl for 2 h, disintegrated in buffer (pH 6.8) in 01:58–02:15 h: minutes, and fulfilled dissolution criteria (pH 7.5) for both United States Pharmacopoeia test-1 and test-2. Thus all seven brands met pre-specified quality criteria.