Spray-dried chitosan/ethylcellulose microspheres for nasal drug delivery: Swelling study and evaluation ofin vitrodrug release properties

Abstract

The aim of this study was to develop spray-dried chitosan-based microspheres, suitable for nasal delivery of loratadine, and to evaluate their potential of modifying loratadine release. The microspheres were composed with ethylcellulose (EC) and chitosan (CM) in two different weight ratios, 1:2 and 1:3. One-phase systems (dispersions) and two-phase systems (emulsions and suspensions) were subjected to spray-drying, resulting in conventional and composed microspheres, respectively. The microspheres were evaluated with respect to the yield, particle size, encapsulation efficiency, physical state of the drug in the polymer matrix, swelling properties and in vitro drug release profile. It was shown that particle size, swelling ability and loratadine release from spray-dried microspheres were significantly affected by the polymeric composition and feed concentration in spray-drying process. Emulsifying method to produce composed EC/CM microspheres resulted in improved loratadine entrapment and moderate swelling, when compared to conventional chitosan microspheres. It seems like better formation of EC cores and chitosan coating were obtained when higher feed concentration and ultrasonic homogenization were employed in the preparation of emulsion systems and when EC to CM weight ratio was 1:3.

Preliminary Studies on Solid Lipid Microparticles of Loratadine for the Treatment of Allergic Reactions via the Nasal Route

“…Topical application of LRT could be an alternative to oral administration. Thus, topical applications of LRT including nasal [3], ophthalmic [1] and skin [4] have been reported for the treatment of allergic rhinitis, asthma and various allergic illnesses in the last few years.…”

Synthesis and characterization of biodegradable microcapsules for the controlled delivery of calcium hydroxide

“…[22][23][24] EC has been used widely as a coating material for drugs. 25,26 Using SEM, the microparticles produced were seen to be smooth and spherical. EDS confirmed the presence of calcium hydroxide in all microparticles.…”

In vitro dissolution/release methods for mucosal delivery systems

“…Franz-diffusion cell was used to assess the drug release properties from numerous formulations aimed for nasal application, such as thermoresponsive soluble gels [55], ion activated in situ gels [56], microparticles [57], nanostructured lipid carriers [58], gel containing microspheres [59], lipidic emulsomes [60], in situ gelling microemulsions [61] and solid lipid nanoparticles [62]. This method is advantageous over other compendial and non-compendial membrane diffusion methods particularly in case of dry powders as it allows them to hydrate slowly, and gel eventually, in humid environment conditions designed to be similar to those encountered in the nasal cavity [63]. It has been also used in case of nano sized and gelling ophthalmic formulations [64,65] as well as for films [66], wafers [67] and tablets [68] aimed for oromucosal administration.…”