Parenteral N-acetylcysteine has a wide variety of clinical applications, but its use can be limited by a poor chemical stability. We managed to control parenteral N-acetylcysteine stability, and to study the influence of additives on the decrease of N-acetylcysteine degradation. First, an HPLC-UV dosing method of N-acetylcysteine and its main degradation product, a dimer, was validated and the stability without additive was studied. Then, the influence of several additives (ascorbic acid, sodium edetate, tocopherol and zinc) and of temperature on N-acetylcysteine dimerization was evaluated. Finally, the influence of zinc gluconate at different concentrations (administrable to patients) was investigated. Zinc gluconate at 62.5 µg·mL⁻¹ allows the stabilization of 25 mg·mL⁻¹ N-acetylcysteine solution for at least 8 days when stored at 5 ± 3 °C.

Background/Objective: Little information is available on the stability and quality controls of compounded 40% dextrose gel required to ensure its safe use in the treatment and prevention of neonatal hypoglycemia. Whether its efficacy relies on buccal absorption also remains uncertain. This study investigates the stability, microbiological safety, rheological properties and dextrose diffusion of a compounded 40% oral dextrose gel, ensuring it can be widely compounded and stored for clinical use. Methods: A 40% dextrose gel compounded with anhydrous dextrose, carboxymethylcellulose, citric acid, sorbic acid and sterile water was subjected to quality control measures including a dextrose content assay, degradation product analysis, microbiological testing and preservative efficacy. Stability studies were conducted at refrigerated (4–8 °C) and ambient temperatures for 7 days and 3 months, respectively. Rheological properties were assessed, and dextrose permeation was measured through an artificial membrane model that mimics a biological membrane. Results: The compounded gel demonstrated stability for up to 7 days at ambient temperature and 90 days when refrigerated. The dextrose content remained within the acceptable range (90–110%) and microbiological tests confirmed compliance with safety standards. The gel exhibited the consistent rheological properties and shear-thinning behavior appropriate for oral mucosal administration. In vitro permeation studies showed no evidence of dextrose diffusion with a long lag time followed by a low steady-state permeation flux. Conclusions: This study validates the compounding process of a stable 40% oral dextrose gel formulation for neonatal hypoglycemia management, which meets quality control criteria and can be safely administered in clinical practice, offering a cost-effective and safe alternative for neonatal care.

Background Carbidopa is a drug mainly used to treat Parkinson’s disease. Associations with levodopa or with levodopa/entacapone are commercialized, but there is no oral formulation of carbidopa alone available in Europe. As carbidopa can also be used as premedication of adult patients for insulinoma diagnosis, it must be compounded as single dose mg capsules. The single dose administration of a magistral preparation implies the compounding of only one capsule, or the loss of consequent quantities of active pharmaceutical ingredient. As an alternative solution, carbidopa capsules could be compounded as batches of hospital preparation. Method With this objective, a stability-indicating dosing method for 200 mg carbidopa capsules was developed. Then, the compounding process was assessed according to the European Pharmacopeia requirements. Finally, the stability of carbidopa capsules stored protected from light at room temperature was studied for one year. Results 200 mg carbidopa capsules compounding process was validated on three independent batches. The beyond use date was fixed at one year. Conclusion Our work confirms that carbidopa 200 mg capsules can be realized in hospital pharmacy and its stability allows the compounding of large batches.