Freeze-drying of ampicillin solid lipid nanoparticles using mannitol as cryoprotectant

Faezeh Alihosseini,Solmaz Ghaffari,Setareh Haghighat,Ali Reza Dabirsiaghi

doi:10.1590/s1984-82502015000400005

Faezeh Alihosseini, Solmaz Ghaffari + Show 2 more

Open Access

https://doi.org/10.1590/s1984-82502015000400005

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Abstract

abstract Solid lipid nanoparticles (SLNs) are interesting colloidal drug-delivery systems, since they have all the advantages of the lipid and polymeric nanoparticles. Freeze-drying is a widely used process for improving the stability of SLNs. Cryoprotectants have been used to decrease SLN aggregations during freeze-drying. In this study Ampicillin was chosen to be loaded in a cholesterol carrier with nano size range. To support the stability of SLNs, freeze-drying was done using mannitol. Particle size, drug release profile and antibacterial effects were studied after freeze-drying in comparison with primary SLNs. Preparations with 5% mannitol showed the least particle size enlargement. The average particle size was 150 and 187 nm before and after freeze-drying, respectively. Freeze-drying did not affect the release profile of drug loaded nanopartilces. Also our study showed that lyophilization did not change the antimicrobial effect of ampicillin SLNs. DSC analysis showed probability of chemical interaction between ampicillin and cholesterol.

Highlights

Preparation of ampicillin SLNsSolid lipid nanoparticles (SLNs) as colloidal carrier systems have the advantages of traditional systems but avoid some of their major disadvantages (Mehnert, Mader, 2001; Hu et al, 2004)
In this study we studied the effect of mannitol in different percentages as cryoprtecant in freeze-drying process on particle size, morphology, drug release profile and antibacterial efficacy of ampicillin SLNs
The evaluation of particles using Malvern zeta sizer (ZEN3600) showed a normal distribution of particle size before and after freeze-drying when the percentage of cryoprotectant was equal to 5%

Summary

INTRODUCTION

Solid lipid nanoparticles (SLNs) as colloidal carrier systems have the advantages of traditional systems but avoid some of their major disadvantages (Mehnert, Mader, 2001; Hu et al, 2004). The enhancement of antibacterial efficacy of antibiotics using SLNs as a carrier was reported as one of the advantages of these colloidal systems (Varshosaz et al, 2010; Alihoseyni et al, 2014). Freeze-drying may generate many stresses that could destabilize colloidal suspension of nanoparticles before turning them to dried particles (Abdelwahed et al, 2006). In this study we studied the effect of mannitol in different percentages as cryoprtecant in freeze-drying process on particle size, morphology, drug release profile and antibacterial efficacy of ampicillin SLNs. Our goal was to prepare freeze-dried ampicillin SLNs and optimize lyophilization process to have minimum impact on their physicochemical and antimicrobial properties. The drug concentration in the supernatant was analyzed using spectrophotometer (Shimadzu, Japan) at 208 nm and the drug-loading efficiency was calculated by using the following equation. (Kimberly, Tabrizian 2005; Ghaffari et al 2012; Alihoseyni et al 2014) The results reported as mean of three analyses with standard deviation

MATERIAL AND METHODS

RESULTS AND DISCUSSION

CONCLUSION