Quality assessment of nine paracetamol 500 mg tablet brands marketed in Saudi Arabia.

Objective: To evaluate in-vitro quality of paracetamol 500 mg tablet brands marketed in Saudi Arabia.

Results: Two reference (R1 and R2) and seven generic (G1-G7) brands were commercially available. Four brands were single-drug, containing paracetamol only (R1, G1-G3) and five contained additional active ingredients (R2, G4-G7).

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.

Eight enteric-coated 50 mg diclofenac sodium tablet formulations marketed in Saudi Arabia: in vitro quality evaluation.

Objective: To evaluate in vitro quality of enteric-coated 50 mg diclofenac sodium tablet formulations on Saudi market.

Results: A reference and seven generic (G1-7) formulations were commercially available in December 2019/January 2020 and were assessed within 25-75% of manufacture-expiration period. Weight variation (range as% difference from mean, n = 20), active substance content (ASC, mean (SD) as% difference from label, n = 20), hardness (mean (SD), n = 10), and friability (% weight loss, n = 20) were 97-103%, 102.

Generic-reference and generic-generic bioequivalence of forty-two, randomly-selected, on-market generic products of fourteen immediate-release oral drugs.

Background: The extents of generic-reference and generic-generic average bioequivalence and intra-subject variation of on-market drug products have not been prospectively studied on a large scale.

Methods: We assessed bioequivalence of 42 generic products of 14 immediate-release oral drugs with the highest number of generic products on the Saudi market. We conducted 14 four-sequence, randomized, crossover studies on the reference and three randomly-selected generic products of amlodipine, amoxicillin, atenolol, cephalexin, ciprofloxacin, clarithromycin, diclofenac, ibuprofen, fluconazole, metformin, metronidazole, paracetamol, omeprazole, and ranitidine.

Does the placebo effect modulate drug bioavailability? Randomized cross-over studies of three drugs.

Background: Medication effect is the sum of its drug, placebo, and drug*placebo interaction effects. It is conceivable that the interaction effect involves modulating drug bioavailability; it was previously observed that being aware of caffeine ingestion may prolong caffeine plasma half-life. This study was set to evaluate such concept using different drugs.

Drug*placebo interaction effect may bias clinical trials interpretation: hybrid balanced placebo and randomized placebo-controlled design.

Background: Conventional randomized placebo-controlled study design assumes the absence of drug*placebo interaction. We hypothesized the presence of such an interaction and that conventionally estimated drug effect might be biased. The objectives of the study were to determine the drug*placebo interaction effect (main) and compare conventionally estimated and interaction model-estimated drug effects (secondary).