Fixed dose combinations for cardiovascular treatment via coaxial electrospraying: Coated amorphous solid dispersion...

As a result of an aging population, the need for fixed dose combinations in the treatment of cardiovascular diseases, that are easy to swallow and administer, has been growing remarkably. In this work, the feasibility of coaxial electrospraying (CES) was investigated to manufacture in one single step, a powder of individually coated particles containing atenolol (ATE), lovastatin (LOV) and acetylsalicylic acid (ASA). To improve the dissolution rate of the poorly water soluble LOV, an amorphous solid dispersion (ASD) of LOV with Soluplus® (SOL) was formulated and Eudragit S100®, an enteric copolymer that only dissolves above pH 7, was applied as coating to avoid LOV hydrolysis in acidic medium. Furthermore, ATE was added to the inner ASD compartment and the acidic ASA was embedded in the coating layer. With regard to the uncoated ASD particles, which were prepared with single nozzle electrospraying, the rate and extent of the LOV dissolution was increased, even to an extent of 100% for the 1/1/6 (ATE/LOV/SOL) ratio. Hence, this ratio was selected and coated particles with proper release of the three APIs could be successfully produced via CES. However, a peculiar behaviour of the coating performance was observed. Regarding LOV, the enteric layer of the particles performed as expected in acidic medium and supersaturation was obtained after the switch to a neutral pH, but in contrast, over 50% of ATE was released after 90 min in acidic medium. Nonetheless, hardly any ATE was released under acidic circumstances from ATE tablets that were, as a benchmark, manually dip-coated with Eudragit S100®. Two different model APIs, namely paracetamol (well soluble) and fenofibrate (poorly soluble) were tested as well, revealing similar discrepancy in the coating performance. The coating layer formed during CES is most likely less dense as compared to the layer produced with tablet coating and consequently, more permeable for highly soluble APIs, but not for the poorly soluble compounds.