Background: Clonazepam is a benzodiazepine drug indicated in all clinical forms of epileptic seizures, various forms of myoclonic seizures, myoclonus and other abnormal movements. At present, it is classified as a hazardous drug requiring special precautions for personnel at reproductive risk, according to a technical document produced by the Spanish National Institute for Safety and Health at Work (INSST), in collaboration with the Spanish Society of Hospital Pharmacy (SEFH). The commercial solutions of clonazepam, for oral and parenteral administration, are supplied by laboratories in glass containers. Repacking in pre-filled polypropylene (PP) syringes, made in the pharmacy service, and in aseptic conditions, may facilitate its administration and reduce the risks to the health or safety of nursing personnel. Nevertheless, there is a lack of stability studies of clonazepam in pre-filled PP syringes. Objectives: To evaluate the physicochemical stability of commercial clonazepam 2.5 mg/mL oral solution and 1 mg/mL parenteral solution repackaged in pre-filled PP syringes under various storage conditions. Methods: A rapid, linear, precise and sensitive high-performance liquid chromatography (HPLC) method for chemical stability studies of Clonazepam 1 mg/mL (parenteral use) and 2.5 mg/mL (oral use) in solution was implemented after repackaging in pre-filled PP syringes. The studies were conducted by measuring concentrations of oral and parenteral clonazepam in pre-filled syringes, at various time points, over 30 days in several different storage conditions: oral clonazepam protected from light in refrigerator and at controlled room temperature exposed to ambient light; parenteral clonazepam protected from light in a refrigerator and at controlled room temperature protected or unprotected from light. Visual aspects and pH change as well as crystal formation were checked to determine physical stability. Results: The degradation of the active ingredient in all groups was less than 10% after 30 days. No evidence of crystal formation, pH and visual aspect changes were observed. Conclusions: Clonazepam 1 mg/mL parenteral solution and 2.5 mg/mL oral solution in pre-filled PP syringes are stable for up to 30 days in the tested conditions. The centralized repackaging of clonazepam in pre-filled PP syringes, connected to a closed safety system, in the pharmacy service, reduces drug manipulation by nursing staff decreasing the risk of occupational exposure.

Background/Objectives: Meropenem is a broad-spectrum carbapenem antibiotic with demonstrated efficacy against multidrug-resistant Gram-negative pathogens. Although its use as an ophthalmic formulation is off-label, growing clinical evidence supports its application in severe ocular infections such as keratitis and endophthalmitis. However, the intrinsic instability of meropenem in aqueous solutions and the absence of standardized ophthalmic preparations limit its routine use. Furthermore, no stability studies are currently available for meropenem 50 mg/mL eye drops stored in polypropylene (PP) dropper bottles under freezing and subsequent refrigerated conditions. The aim of this study was to evaluate the physicochemical and microbiological stability of a 50 mg/mL meropenem ophthalmic solution prepared in a hospital pharmacy using a commercial meropenem pharmaceutical product, and packaged in PP containers. Methods: Eye drops were aseptically prepared from a commercially available pharmaceutical product, containing 1g de meropenem and anhydrous sodium carbonate as an excipient. After preparation, the drops were stored at −20 ± 2 °C for up to 42 days, followed by refrigerated storage (5 ± 3 °C) after thawing for up to 7 days. Chemical stability was assessed using a validated stability-indicating HPLC method in accordance with ICH guidelines and was defined as 90–110% recovery of the initial concentration. Physical stability (appearance, pH, particulate matter) and microbiological stability were also evaluated under simulated in-use conditions. Results: The HPLC method demonstrated excellent linearity, precision, and accuracy. Meropenem concentrations remained within the predefined acceptance limits throughout the 42-day study period under freezing conditions, with no significant changes in pH, color, or particulate formation. After thawing, a progressive decrease in drug concentration was observed under refrigerated conditions, falling below 90% of the initial concentration within 24–48 h. A concomitant color change from colorless to yellow was also detected, consistent with β-lactam ring hydrolysis. Despite this degradation, no significant changes in physical parameters other than color were observed, and microbiological testing confirmed sterility for up to 7 days under refrigerated conditions. Conclusions: Meropenem drops 50 mg/mL in PP dropper bottles are physicochemically and microbiologically stable for 43 days (42 days under frozen conditions plus 1 day, in-use conditions, after opening and under refrigeration).

Background/ Objectives: Oseltamivir is a widely used antiviral agent indicated for the treatment of influenza and plays a central role in pandemic preparedness strategies. Although an extemporaneously prepared 15 mg/mL oral suspension is recognized in formularies, preparing large volumes during a pandemic requires extended storage options. However, no stability studies are currently available for an oseltamivir 15 mg/mL oral suspension stored under freezing and subsequent refrigerated conditions for the duration of a standard treatment. The aim of this study was to evaluate the physicochemical and microbiological stability of a 15 mg/mL oseltamivir oral suspension prepared from the active pharmaceutical ingredient (API) and packaged in amber glass containers. Methods: The oral suspension was formulated using oseltamivir phosphate API, sodium benzoate as a preservative, and purified water, and then packaged in 125 mL Type II amber glass bottles allowing for thermal expansion. The samples were stored at −20 ± 2 °C for up to 75 days, followed by refrigerated storage (5 ± 3 °C) after thawing for up to 10 days. Chemical stability was assessed using a validated HPLC method in accordance with ICH guidelines and was defined as 90–110% recovery of the initial concentration. Physical stability (color, pH, particulate matter, crystallization, and homogeneity) and microbiological stability were also evaluated. Results: The HPLC method demonstrated excellent linearity, precision, and accuracy. Oseltamivir concentrations remained within the predefined acceptance limits throughout the 75-day study period under freezing conditions, with no significant changes in pH, color, or particulate formation. After thawing, the drug concentration continued to remain fully stable and within the required limits for up to 10 days under refrigerated conditions. Despite the prolonged storage and phase changes, no significant changes in physical parameters were observed, and microbiological testing confirmed the absence of aerobic, anaerobic, and fungal microorganisms on the final day of the study. Conclusions: Oseltamivir 15 mg/mL oral suspension in amber glass bottles is physicochemically and microbiologically stable for up to 85 days (75 days under frozen conditions plus 10 days under refrigeration after thawing).

Background/ Objectives: Meropenem is a broad-spectrum carbapenem antibiotic with demonstrated efficacy against multidrug-resistant Gram-negative pathogens. Alt-hough its use as an ophthalmic formulation is off-label, growing clinical evidence sup-ports its application in severe ocular infections such as keratitis and endophthalmitis. However, the intrinsic instability of meropenem in aqueous solutions and the absence of standardized ophthalmic preparations limit its routine use. Furthermore, no stability studies are currently available for meropenem 50 mg/mL eye drops stored in polypro-pylene (PP) dropper bottles under freezing and subsequent refrigerated conditions. The aim of this study was to evaluate the physicochemical and microbiological stability of a 50 mg/mL meropenem ophthalmic solution prepared in hospital pharmacy and packaged in PP containers. Methods: Eye drops were aseptically prepared and stored at −20 ± 2 °C for up to 42 days, followed by refrigerated storage (5 ± 3 °C) after thawing for up to 7 days. Chemical stability was assessed using a validated stability-indicating HPLC method in accordance with ICH guidelines and was defined as 90–110% recovery of the initial concentration. Physical stability (appearance, pH, particulate matter) and micro-biological stability were also evaluated under simulated in-use conditions. Results: The HPLC method demonstrated excellent linearity, precision, and accuracy. Meropenem concentrations remained within the predefined acceptance limits throughout the 42-day study period under freezing conditions, with no significant changes in pH, color, or par-ticulate formation. After thawing, a progressive decrease in drug concentration was ob-served under refrigerated conditions, falling below 90% of the initial concentration within 24–48 hours. A concomitant color change from colorless to yellow was also detected, consistent with β-lactam ring hydrolysis. Despite this degradation, no significant changes in physical parameters other than color were observed, and microbiological testing con-firmed sterility for up to 7 days under refrigerated conditions. Conclusions: Meropenem drops 50 mg/mL in PP dropper bottles is physicochemically and microbiologically stable for 43 days (42 days under frozen conditions plus 1 day, in-use conditions, after opening and under refrigeration).

Background: Clonazepam is a benzodiazepine drug indicated in all clinical forms of epileptic seizures, various forms of myoclonic seizures, myoclonus and other abnormal movements. At present, it is classified as a hazardous drug requiring special precautions for personnel at reproductive risk, according to a technical document produced by the Spanish National Institute for Safety and Health at Work (INSST), in collaboration with the Spanish Society of Hospital Pharmacy (SEFH). The commercial solutions of clonazepam, for oral and parenteral administration, are supplied by laboratories in glass containers. Repacking in pre-filled polypropylene (PP) syringes, made in the pharmacy service, in aseptic conditions, may facilitate its administration and reduce the risks to the health or safety of nursing personnel. Nevertheless, there is a lack of stability studies of clonazepam in pre-filled PP syringes. Objectives: To evaluate the physicochemical stability of commercial clonazepam 2.5mg/mL oral solution and 1mg/mL parenteral solution repackaged in pre-filled PP syringes under various storage conditions. Methods: A rapid, linear, precise and sensitive high-performance liquid chromatography (HPLC) method for chemical stability studies of Clonazepam 1 mg/mL (parenteral use) and 2.5 mg/mL (oral use) in solution was implemented after repackaging in pre-filled PP syringes. The studies were conducted by measuring concentrations of oral and parenteral Clonazepam in pre-filled syringes, at various time points, over 30 days in several different storage conditions: oral clonazepam protected from light in refrigerator and at controlled room temperature exposed to ambient light; parenteral clonazepam protected from light in refrigerator and at controlled room temperature protected or unprotected from light. Visual aspects and pH change as well as crystal formation were checked to determine physical stability. Results: The degradation of the active ingredient in all groups was less than 10% after 30 days. No evidence of crystal formation, pH and visual aspect changes were observed. Conclusions: Clonazepam 1 mg/mL parenteral solution and 2.5 mg/mL oral solution in pre-filled PP syringes are stable for up to 30 days in the tested conditions. The centralized repackaging of clonazepam in pre-filled PP syringes, connected to a closed safety system, in the pharmacy service, reduces drug manipulation by nursing staff decreasing the risk of occupational exposure.

Background/Objectives: Oseltamivir is a widely used antiviral agent indicated for the treatment of influenza and plays a central role in pandemic preparedness strategies. Although an extemporaneously prepared 15 mg/mL oral solution is recognized in formularies, preparing large volumes during a pandemic requires extended storage options. However, no stability studies are currently available for an oseltamivir 15 mg/mL oral solution stored under freezing and subsequent refrigerated conditions for the duration of a standard treatment. The aim of this study was to evaluate the physicochemical and microbiological stability of a 15 mg/mL oseltamivir oral solution prepared from the active pharmaceutical ingredient (API) and packaged in amber glass containers. Methods: The oral solution was formulated using oseltamivir phosphate API, sodium benzoate as a preservative, and purified water and then packaged in 125 mL Type II amber glass bottles, allowing for thermal expansion. The samples were stored at −20 ± 2 °C for up to 75 days, followed by refrigerated storage (5 ± 3 °C) after thawing for up to 10 days. Chemical stability was assessed using a validated HPLC method in accordance with ICH guidelines and was defined as 90–110% recovery of the initial concentration. Physical stability (color, pH, particulate matter, crystallization, and homogeneity) and microbiological stability were also evaluated. Results: The HPLC method demonstrated excellent linearity, precision, and accuracy. Oseltamivir concentrations remained within the predefined acceptance limits throughout the 75-day study period under freezing conditions, with no significant changes in pH, color, or particulate formation. After thawing, the drug concentration continued to remain fully stable and within the required limits for up to 10 days under refrigerated conditions. Despite the prolonged storage and phase changes, no significant changes in physical parameters were observed, and microbiological testing confirmed the absence of aerobic, anaerobic, and fungal microorganisms on the final day of the study. Conclusions : Oseltamivir 15 mg/mL oral solution in amber glass bottles is physicochemically and microbiologically stable for up to 85 days (75 days under frozen conditions plus 10 days under refrigeration after thawing).