Thermoanalytical study of praziquantel-loaded PLGA nanoparticles

Abstract

Polymeric nanoparticles have received great attention as potential controlled drug delivery systems. Biodegradable polymers has been extensively used in the development of these drug carriers, and the polyesters such as polylactic acid, polyglycolic acid and their copolymers as poly-lactide-co-glycolide are the most used, considering its biocompatibility and biodegradability. Thermal analysis techniques have been used for pharmaceutical substances for more than 30 years and are routine methods for screening drugexcipient interactions. The aim of this work is to use thermal analysis to characterize PLGA nanoparticles containing a hydrophobic drug, praziquantel. The results show that the drug is in an amorphous INTRODUCTIONNanoparticles are considered one of the most promising dosage forms as potential formulations for sitespecific drug delivery system including drug targeting (Mainardes, Silva, 2004;Hans, Lowman, 2002). Colloidal polymeric particles used as drug carriers can be made of artificial or natural polymers, which must be biocompatible (Soppimath et al., 2001; Gorner et al., 1999). In the past two decades, many works have been carried out in order to apply biocompatible and/or biodegradable polymers in drug delivery systems (Jain, 2000).Nanoparticles are a collective name for nanospheres and nanocapsules. Nanospheres have a matrix type structure, where active compounds can be adsorbed on their surface, entrapped or dissolved into the matrix. Nanocapsules have a polymeric shell and an inner core. In this case, the active substances are usually dissolved in the core, but may also be adsorbed on their surface (Allemann et al., 1998;Panyam, Labhasetwar, 2003).Although a number of different polymers have been investigated for formulating biodegradable nanoparticles, polymers of poly(L-lactic-acid) (PLA) and their copolymers with glycolic acid (PLGA) have been extensively used in controlled drug delivery systems. The lactide/glycolide polymers chains are cleaved by hydrolysis to form natural metabolites (lactic and glycolic acids), which are eliminated from the body through the citric acid cycle. PLGA provides a wide range of degradation rates, from months to years, depending on its composition and molecular weight (Mainardes, Evangelista, 2005;Uhrich et al., 1999;Vert et al., 1998;Anderson, Shive, 1997;Burkersroda et al., 2002).Aliphatic polyesters are polymers of the poly(α-hidroxy) acids class, one of the polymers families more attractive and promising, because their members are biocompatible and bioresorbable and could be used in several applications in the medicinal area (Iannace et al., 1994). The presence of the ester linkage makes these polymers hydrolytically unstable, this means that they can be degraded when in contact with the corporal fluids, resulting in products that are reabsorbed by the organism, as part of the carbohydrates metabolism (Beiser, Kanat, 1990). In the last years, the biodegradable polymers have gained a growing importance in the medical area. They have been used in a wide number ...

Preparation and characterisation of Dextran-70 hydrogel for controlled release of praziquantel

“…The bands at 2929.87 cm -1 and 2852.72 cm -1 are CH vibrations of the symmetric and asymmetric CH 3 and CH 2 axial deformations, which have previously been observed in PZQ-loaded nanoparticles by Mainardes et al (2006). According to these authors, a band at 1630 cm -1 stems from carbonyl stretching, and is observed at 1649.14 cm -1 (Figure 2a) in this case.…”

“…According to these authors, a band at 1630 cm -1 stems from carbonyl stretching, and is observed at 1649.14 cm -1 (Figure 2a) in this case. Furthermore, several overlapping bands are seen between 1350 and 1000 cm -1 , indicating CN axial deformation (Mainardes et al, 2006). As noted by Stenekes et al (2001) and Pitarresi et al (2007), in the absorption spectrum of dextran (Figure 2b) there is a broad band at 3448 cm -1 , resulting from OH stretching in the polymer chain.…”

Evaluation of Surfactants-Assisted Folic Acid-Loaded Pectin Submicrospheres: Characterization and Hemocompatibility Assay

“…While evaluating the experiment, any interaction occurring between the folic acid and pectin polymer would produce altered vibrations of their atoms involved in the interaction. Normally, the change in the frequency and intensity of interacted molecules and uninterested (stand-alone) complexes were compared with their respective standard compounds in free form (here folic acid-alone and pectin-alone) [40]. Figure 3 exhibited FT-IR spectra of folic acid-alone (F) and formulations containing folic acid free-pectin submicrospheres with/without surfactants (PE1, PE3 and PE5) and formulations of folic acid-loaded pectin submicrospheres with/without surfactants (PE2, PE4 and PE6), respectively.…”

Nanotechnology-based drug delivery systems and herbal medicines: a review

“…Polymeric nanoparticles are a promising formulation used for drug delivery systems, because they can be targeted. 31,32 Polymeric nanoparticles are colloidal systems that work as vectors to control drug release, targeting it toward specific locations. Compared against conventional formulations, polymeric nanoparticles can increase the solubility of constituents, reduce the therapeutic dose, and improve absorption of the active components.…”