Formulation of Natural Polymeric Nanoparticles to Overcome Barriers for the Treatment of Osteoporosis

Aims: The present paper focuses on natural polymeric nanoparticles (NPs), described in the literature as the most effective natural polymer that have been introduced in the last decades, We have recently developed an innovative approach to this aim: a new osteotropic biomaterial was prepared, based on the conjugation of natural polymer with the bisphosphonate drug alendronate sodium (ALS). Alendronate sodium causes oesophageal side effects as ulceration. Hence, preventing the free ALS from coming in direct contact with the GI mucosa thereby reducing the possibility of side effects.

Methodology: Nanoparticles were prepared by adding drop wise aqueous solution of drug to Chitosan (CS) solutions under stirring. Above solution added to aqueous solution containing stabilizer. Mannitol as bioprotectants were used to prevent particle aggregation and to reduce mechanical stress during freezing and drying processes.

Results: The prepared ALS-loaded NPs were investigated for their physicochemical, morphological and structural characteristics by dynamic light scattering, differential scanning calorimetry, Entrapment efficacy and actual drug content were assessed by UV spectrophotometric method at 565 nm. In vitro dissolution tests performed in simulated gastro-intestinal fluids and phosphate buffer solution pH 6.8 revealed a prolonged release of ALS of 48 h. Improvement of nanoparticle stability after lyophilisation was observed in the presence of bioprotectants.

Conclusion: The ionic gelation method with low-MW chitosan was effective in achieving reproducible nanoparticles with the desired physico-chemical and safety characteristics.