Didanosine-loaded poly(epsilon-caprolactone) microparticles by a electrospray technique

SEREMETA, KP; ABRAHAM, GA; SOSNIK, A

Lisboa

Encuentro; 9th World Meeting on Pharmaceutics, Biopharmaceutics and Pharmaceutical Technology; 2014

Lisbon Portugal-Research Pharm

Electrospray or Electrohydrodynamic atomization (EHDA) is a process based on the theory of charged droplets, where an electric field applied to a liquid droplet exiting a capillary is able to deform the interface of the droplet ) (see Figure 1A). The electric charge generates an electrostatic force inside the droplet which competes with the surface tension of the droplet, forming a cone (Taylor) (see Figure 1B). The excess of charge then needs to be dissipated, resulting in the formation of smaller (at the nano- and micro-scale) charged droplets that are ejected from the primary droplet. Due to Coulomb repulsion of the charges, the droplets are dispersed well and they do not coalesce during their flight toward the collector (1). Co-axial EHDA (CEHDA) is a variant of conventional EHDA. In this process, two concentric capillaries are used, and two different immiscible liquids can be pushed through these capillaries (2) (see Figure 1A). The objective of this technology is to protect the active core material from the external environment (3). Didanosine (ddI) is a first-line antiretroviral used in the cocktail against the Human Immunodeficiency Virus (HIV). Its oral bioavailability is reported to range from 20% to 40% owing to the hydrolysis in the acid gastric pH to its corresponding inactive purine derivative, hypoxanthine (4). In general, the free drug is administered in buffered tablets to prevent its deactivation when exposed to the low pH of the stomach (5). Therefore, the encapsulation of ddI within polymeric particles is a strategy to stabilize it. In this work, we encapsulated ddI within poly(epsilon-caprolactone) (PCL) (6) by means of EHDA and CEHDA and characterized the critical parameters of the process by a broad variety of techniques.