Mucoadhesive chitosan microspheres of carvedilol for nasal administration

Abstract

The aim of the present study was to develop and characterize chitosan mucoadhesive microspheres of carvedilol (CRV) for nasal delivery to improve bioavailability for treatment of hypertension and angina pectoris. The microspheres were prepared by emulsification-cross-linking method and evaluated for size, shape, entrapment efficiency (EE), in vitro mucoadhesion, in vitro drug release, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The mucoadhesive properties were also evaluated by Freundlich and Langmuir adsorption isotherms. In vivo tests were carried out in rabbits. The microspheres were spherical with size of 20-50 microm, which is favorable for intranasal absorption. The EE was observed from 42% to 68% while percentage mucoadhesion was from 74% to 88%. A strong interaction between mucin and chitosan microspheres was detected explaining adsorption with electrostatic interaction. The microspheres released around 75% of drug in 8 h. DSC and XRD studies revealed that CRV was molecularly dispersed. The absorption rate was rapid and the absolute bioavailability was high, 72.29%. The gamma scintigraphy indicated that the microspheres cleared slowly from the nasal cavity. It was concluded that chitosan microspheres could be used to deliver CRV following nasal administration for improving the bioavailability.

Comparative study between simple and optimized liposomal dispersion of quetiapine fumarate for diffusion through nasal route

“…This obviously exhibits significant radioactivity aggregation in the brain after intranasal administration for a desired period and these results were in great concurrence with the past discoveries (Patil et al, 2010). Results of gamma scintigraphy study revealed that liposomal dispersion shows more accumulated 99m Tc into the brain in comparison with simple dispersion.…”

Enhanced targeting efficiency of PLGA microspheres loaded with Lornoxicam for intra-articular administration

“…Recently, the use of polymeric carriers in formulations of therapeutic drug delivery systems, such as gelatin (TabataIkada 1989;Tabata et al 1999;Sakakibara et al 2002), chitosan (Guo et al 2010;Patil et al 2010), Poly(lactide-co-glycolide) (PLGA) (TsungBurgess 2001) and poly(lactic acid) (PLA) (ShiveAnderson 1997), has gained widespread application, due to their advantage of being biodegradable and biocompatible (Tuncay et al 2000). Among the various polymeric carrier systems, PLGA microspheres have been shown to be very suitable…”

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“…After 24 h, the filtrate was diluted with phosphate buffer pH 6.4 and final solution was assayed spectrophotometrically at 232 nm for drug content. [16,17,18] Estimated drug content % Entrapment efficiency = ×100 Theoretical drug content…”

“…At predetermined time interval of 0, 1, 2, 3, 4, 5, 6, 7, and 8 h, 1ml of sample was withdrawn, diluted, filtered, and analyzed by UV Visible spectrophotometer at 232 nm. [11,24,26,29,30] Fourier transforms infrared spectroscopy…”