(291f) Production of Biological Carriers by Electrospraying

The development of new therapies can be conditioned by the lack of suitable and effective ways to carry the biological molecules into the target inside the patient's body. The small amounts of the biomolecules are very difficult to quantify in the solid state and is not always possible to use a simple excipient. Very frequently, the size and density differences between the biomolecules and the excipient are so large that a uniform distribution of the therapeutic cannot be ensured, especially when they are not compacted in a tablet. This is the case for certain dry powder inhalers and powders to prepare suspensions. In addition, the properties of the excipient can improve the formulation by reducing the risk of local overdose and by giving an additional control over the farmacokinetics, as long as it is ensured that it does not separate from the biomolecule in the exact instant when it enters the patient's body. This feature has been used and widely described in literature through encapsulation processes of the biomolecule by the excipient. Although useful and with a wide range of applications, this approach is also limited concerning the type of excipients that can be used. In this work a new approach is proposed, where the biomolecule forms a covering layer on the surface of the particles of excipient. The covering step consists of the deposition of biomolecule particles on the surface of the tribocharged excipient by electrospraying. Using this approach, the binding between the biomolecule and the excipient is achieved using van der Waals forces. This avoids introducing chemical or biological changes in both substances. As model compounds, lactose was used as excipient and a protein (Bovine serum albumin) was used as biomolecule. The effect of the process parameters, like electrical field intensity, nozzle to target distance, concentration of protein in the suspension and time of exposition of excipient to the electrospray plume were analyzed. The determination of the percentage of covered surface was performed by Scanning Electronic Microscopy. The simplicity of the method, its reproducibility and its straightforward scale-up show that this method is suitable for commercial pharmaceutical applications.