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Studies on biodegradable polymeric nanoparticles of risperidone: in vitro and in vivo evaluation
Madaswamy S Muthu1, Sanjay Singh
1Institute of Medical Sciences, Department of Pharmacology, Banaras Hindu University, Varanasi - 221005, India. muthubits@rediffmail.com
Aim:
The aim of this work was to develop extended-release risperidone nanoparticles for parenteral delivery (intravenous) and to reduce the dose-dependent extrapyramidal side effects of risperidone.
Methods:
Polymeric nanoparticles containing risperidone made of poly (epsilon-caprolactone) were designed by the nanoprecipitation method using polymeric stabilizers (poloxamers). The in vivo efficacy of prepared formulations and the risperidone solution was studied by administering them intravenously to apomorphine-treated mice. Extrapyramidal side effects of the risperidone and its formulations were also studied.
Results:
The particle size of the prepared nanoparticles ranged between 99 and 304 nm. Approximately 78-85% drug-encapsulation efficiency was achieved when risperidone was loaded at 1.7-4.1% by weight of the polymer. During in vivo studies, prepared risperidone-containing formulations showed a significant prolonged antipsychotic effect than that of risperidone solution, also having less extrapyramidal side effects.
Conclusion:
The prolonged effect of risperidone was obtained from the nanoparticles of risperidone administered by the intravenous route and this may improve the treatment of psychotic disorders by dose reduction.
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