Stability of 5 mg/mL Nitrendipine Oral Suspension in Syrspend® SF PH4

Abstract

Abstract Background Nitrendipine is prescribed to children for the treatment of primary hypertension (off-label use). Available specialties (Nidrel®, Baypress® and others generic drugs) are only marketed in tablet form, which is unsuitable for pediatric use. A hospital preparation of nitrendipine oral suspension at 5 mg/mL was developed. The aim of the study was to determine physicochemical and microbiological stability of the nitrendipine oral suspension in order to set a shelf life for the preparation. Methods A validated high-performance liquid chromatographic (HPLC) method was developed for the assay of nitrendipine. Nitrendipine oral suspensions were prepared using 20 mg Nidrel® tablets and suspending vehicle Syrspend® SF PH4. These preparations were packaged in amber glass bottles and stored at room temperature. The physicochemical (pH, osmolality, nitrendipine concentration, macroscopic changes) and microbiological stability of the preparation was tested over 90 days. Nitrendipine concentration at day 0 was considered as 100 % and nitrendipine concentration in subsequent samples greater than 95 % were considered stable. Results The developed HPLC method was validated in terms of linearity, accuracy, precision and specificity. After 90 days, no significant pH and osmolality variation was observed. No microbial growth was noted. Concentrations of nitrendipine were found to be always higher 95 % of the initial concentration. Conclusions Nitrendipine oral suspensions 5 mg/mL are stable for at least 90 days when stored at temperature room and in amber glass bottles. This suspension is more suitable for children than tablets and allows obtaining accurate doses based on patient’s body weight.