Abdelmoneim Saleh

Gamma irradiation presents a significant challenge for chemically labile pharmaceuticals due to the risk of degradation and reduced efficacy. This study introduces a novel dual-index framework to quantitatively assess the gamma sterilization risk of three ACE inhibitors (benazepril, quinapril and cilazapril) by integrating chromatographic degradation data with Monte Carlo-based radiation interaction metrics. Forced degradation experiments were conducted under acidic, basic, oxidative, photolytic, and thermal conditions, and degradation behavior was evaluated using reverse-phase liquid chromatography (RPLC). Based on normalized degradation profiles a compound-specific Chemical Fragility Index (CFI) was determined with cilazapril showing the highest fragility (CFI = 0.572), followed by quinapril (0.539) and benazepril (0.081).Monte Carlo simulations (MCNPX v2.7.0) were used to compute key gamma interaction parameters (kerma, dose rate, effective atomic number, and energy absorption buildup factor) at 1.25 MeV, leading to the development of the Physics Energy Deposition Index (PEDI). Benazepril exhibited the highest energy deposition potential, while cilazapril showed minimal interaction. By combining CFI and PEDI a unified Radiosterilization Risk Score (RRS) was derived, identifying quinapril as the most vulnerable compound, followed by benazepril and cilazapril.This integrated methodology is the first to quantitatively link chromatographic degradation behavior with radiation physics, offering a predictive and transferable tool for early-stage sterilization compatibility screening across pharmaceutical classes. The CFI–PEDI–RRS framework supports rational sterilization strategy development while reducing reliance on destructive testing.

The current study investigates the presence ²²²Rn in tap water, natural spring water, and well water from various locations in Er-Rachidia, Morocco, to assess the potential radiological risks posed to the local community. Radon, a radioactive gas produced by the decay of uranium and thorium in rocks and soil, poses significant radiation hazards. Using a Nuclear Track Detector (LR-115), researchers investigated the presence of radon in water from wells, dams, and rivers. The highest radon concentrations are found in well water, with an average of 1.92 Bq/L. The concentration of river water is the lowest, coming in at 0.53 Bq/L, while the average concentration of dam water is 0.84 Bq/L. On average, the annual effective dosage for well water is 4.57 ms per year. The water dosages from dams range from 1.74 to 2.44 μSv/y, with 1.98 being the average. River water ranges from 0.51 to 1.69 mSv/y, averaging 1.24 µSv/y. The excess lifetime cancer risk varies significantly across water sources: 1.27 × 10−3 to 1.84 × 10−3 (average 1.60 × 10−3) for well water, 0.61 × 10−3 to 0.85 × 10−3 (average 0.69 × 10−3) for dam water, and 0.18 × 10−3 to 0.59 × 10−3 (average 0.43 × 10−3) for river water. The results dispel fears of significant radioactive dangers to the locals by suggesting that the measured radon concentrations are within the limits set by international organizations.