Chemical and microbiological stability studies of an aqueous solution of pravastatin sodium salt for drug therapy of the dysphagic patients

Objective This study is aimed to improve dysphagic patient compliance under therapy with cholesterollowering drugs. Patients suffering severe dysphagia, who do not feed independently, receive enteral nutrition through feeding tube and they need alternative oral route also for the administration of pharmacological therapy. This research deals with the development and stability (chemical and microbiological) of an aqueous solution of pravastatin sodium salt that will be administered orally directly in the feeding tube starting from commercial tablets. Tablets formulation is the only pharmaceutical dosage form available on the market for this type of drug. Methods Pravastatin sodium salt tablets are dissolved in a preserved sodium bicarbonate solution at the final concentration of 4 mg/mL. Samples are stored in two different conditions until 60 days. The samples are prepared for high-performance liquid chromatography analysis coupled to a diode array detector (HPLC-DAD), microbiological analysis and pH measurements. Results The chemical stability of the solution performed with HPLC-DAD analysis shows peaks' overlapping, which are characteristic of pravastatin, and correspondence of the concentration of the active ingredient in the solution. The detected values are analysed by one-way analysis of variance showing no statistically significant differences. Microbiological analyses proved that there is not microbial growth. By considering the dilution factor applied, it was possible to express the result as <10 CFU/mL in the two different culture media. Conclusion This study demonstrated the possibility to reformulate pravastatin tablets as liquid pharmaceutical formulation for enteral administration with the aim of improving drug therapy in dysphagic patients.