Electrospun fixed dose formulations of amlodipine besylate and valsartan
Increasing numbers of elderly people require multi-drug therapies. One route to improve adherence rates is to prepare fixed dose combinations (FDCs), in which multiple active ingredients are loadedinto a single formulation. Here, we report the use of electrospinning to prepare fast-dissolving oral FDCs containing amlodipine besylate and valsartan, two drugs prescribed as FDCs for the treatmentof hypertension. Electrospun fibers were prepared loaded with one or both drugs, using polyvinylpyrrolidone as the polymer matrix. The fibers were cylindrical in morphology and comprise amorphoussolid dispersions except with the highest loadings of amlodipine besylate. HPLC demonstrated drug entrapment efficiencies of between 90 and 99% of the theoretical dose. The mats have foldingendurances and thicknesses suitable for use as oral films. The amlodipine besylate-loaded systems are fast-dissolving, with 100% release obtained within 120 s. In contrast, valsartan release from itssingle-drug formulations took longer, ranging from 360 s to 24 min. With the FDC formulations, rapid release within 360 s was achieved when the loading was 5% w/w of each drug, but again the releasetime increased with drug loading. Electrospun fibers therefore have significant promise as FDCs, but the target drug and its loading need to be carefully considered.