3PC-003 Formulation of an oral paediatric suspension of amlodipine 1 mg/ml: adaptation to the national formulary and stability testing

<h3>Background and Importance</h3> Amlodipine is a calcium channel blocker used to treat high blood pressure. In paediatric patients it is administered in liquid formulations with a recommended dose of 2.5 mg to 5 mg daily single dose. At the hospital, the available formulation was an oral suspension that, when settling, formed a compact cake that was difficult to redisperse. Therefore, the paediatric department requested a new formulation that was more easily redispersible but with the same concentration. <h3>Aim and Objectives</h3> Formulate a readily redispersible oral suspension of amlodipine 1 mg/mL and assess its quality and stability. <h3>Material and Methods</h3> The original formulation was adapted according to the National Formulary (NF), replacing the methylcellulose with propylene glycol-free preservative water and reducing the simple syrup. The concentration was adjusted to 1 mg/mL (the formulation described in the NF is 0.5 mg/mL) using 10 mg amlodipine tablets, as the pure product was not available. The period of validity was determined according to the Guide to Good Practice in the Preparation of Medicines in Hospital Pharmacy Services. During validation, parameters such as redispersion time, colour, odour and pH were evaluated weekly. <h3>Results</h3> A shelf life of 30 days in a refrigerator (2–8°C) was assigned as it was considered an oral, non-sterile magistral formula, with physicochemical stability studies, with preservatives (nipagin, nipasol) but without microbiological stability studies. During the study period the formulation was maintained with an immediate redispersion time, easy redispersion was observed after gentle agitation, the colour of the formulation as well as the odour remained unchanged, and the pH was maintained at values between 5.5–6.5 as indicated by the NF. <h3>Conclusion and Relevance</h3> The formulation was successfully adapted to that indicated in the NF, maintaining the concentration of the original. It is evident that the formulation developed maintains its stability for 30 days, being effective and safe, improving redispersion and facilitating the work of the nursing staff. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest