NMR cryoporometry characterisation studies of the relation between drug release profile and pore structural evolution of polymeric nanoparticles.
Bottom Line: PLGA/PLA polymeric nanoparticles could potentially enhance the effectiveness of convective delivery of drugs, such as carboplatin, to the brain, by enabling a more sustained dosage over a longer time than otherwise possible.For a core-coat nanoparticle formulation, the development of smaller nanopores, following an extended induction period with no structural change, was associated with the onset of substantial drug release.Hence, the specific reasons for the effectiveness of the synthesis route, for obtaining core-coat nanoparticles with delayed release, have been elucidated.
Affiliation: Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK.Show MeSH
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Mentions: Batch C was studied using ESEM, TEM and NMR cryoporometry. The ESEM and TEM images were obtained after dispersing the sample in water and then placing them on a grid. They clearly showed the presence of spherical nanoparticles, as seen in Fig. 5(b and c). These nanoparticles are of the order of ∼100 nm in size. The melting curves of aCSF solution containing nanoparticles from batch C, and the nanoparticle drug release profile are plotted in Fig. 6. The drug release profile shows a pulse release of ∼90% of the drug within the first half-day, and thereafter a long slight tail. The melting curves of the aCSF solution containing nanoparticles from batch C were obtained after ∼18 h and ∼2 days. As seen earlier for batch A and batch B, the melting curves were similar after ∼18 h and ∼2 days. However, unlike the smooth melting curves obtained for samples from batches B and A, the melting curves of sample C had the presence of a steeper melting step. The time points at which each melting profile was obtained can be seen in the drug release profile, indicated by each lone symbol corresponding to the appropriate melting profile. As evident from the drug release data, there is very little change in shape of the drug release profile during the time interval investigated. This also correlated with the little change in melting profiles of the aCSF solution in the same time period.
Affiliation: Department of Chemical and Environmental Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK.