Aim: This retrospective analysis aimed to comprehensively review the design and regulatory aspects of bioequivalence trials submitted to the Saudi Food and Drug Authority (SFDA) since 2017. Methods: This was a retrospective, comprehensive analysis study. The Data extracted from the SFDA bioequivalence assessment reports were analyzed for reviewing the overall design and regulatory aspects of the successful bioequivalence trials, exploring the impact of the coefficient of variation of within-subject variability (CVw) on some design aspects, and providing an in-depth assessment of bioequivalence trial submissions that were deemed insufficient in demonstrating bioequivalence. Results: A total of 590 bioequivalence trials were included of which 521 demonstrated bioequivalence (440 single active pharmaceutical ingredients [APIs] and 81 fixed combinations). The majority of the successful trials were for cardiovascular drugs (84 out of 521 [16.1%]), and the 2 x 2 crossover design was used in 455 (87.3%) trials. The sample size tended to increase with the increase in the CVw in trials of single APIs. Biopharmaceutics Classification System Class II and IV drugs accounted for the majority of highly variable drugs (58 out of 82 [70.7%]) in the study. Most of the 51 rejected trials were rejected due to concerns related to the study center (n=21 [41.2%]). Conclusion: This comprehensive analysis provides valuable insights into the regulatory and design aspects of bioequivalence trials, and can inform future research and assist in identifying opportunities for improvement in conducting bioequivalence trials in Saudi Arabia.

Aims: Studies suggested that drug pricing might be a risk factor for drug shortage; however, a few provided a quantitative assessment of this possible causal association. This study aimed to assess whether drug prices are associated with drug shortage incidents. Methods: This was a retrospective database analysis study. Drugs with shortage notifications (one drug per notification) that were sent to the Saudi Food and Drug Authority (SFDA) from Jan/2017 to Dec/2020 by different stakeholders were included in the study. For each drug, the foreign-to-Saudi-price ratio (FTSPR) was calculated (FTSPR= mean international price/Saudi price). Accordingly, drugs were split into three groups: Group 1 (FTSPR >1]), Group 2 (FTSPR =1]), and Group 3 (FTSPR <1]). The primary outcomes were the ratio of mean counts (mCR) between the three groups with Group 3 chosen as a control group. The study outcomes were analyzed using a negative binomial regression model adjusting for the measured confounders. All study analyses were conducted using RSudio Version 1.2.5033. Results: A total of 900 drugs were included (Group 1=348, Group 2=345, Group 3=209). The mean count of Group 1 higher was higher than Group 3 (mCR: 1.88; 95% confidence interval [CI] 1.24 to 2.83), while and mean counts of Group 2 vs. Group 3 were comparable (mCR: 1.39; 95%CI 0.92 to 2.09). Discussion: The results of our study showed that shortage was associated with drugs that are more expensive outside Saudi Arabia. Additional international studies are needed to explore this causal association.