Wang et. al. carried out the study on the estradiol(E2)-loaded chitosan nanoparticles (CS-NPs). The nanoparticles were prepared by ionic gelation method and had a mean size of (269.3 ?? 31.6) nm and zeta potential of +25.4 mV. Loading capacity of the E2 CS-NPs suspension and entrapment efficiency was found to be 1.9 mg/ml and 67% respectively. In vivo studies of the formulations were carried out on male Wister rats. E2-CS-NPs were given either intranasally or intravenously and when compared, it was found that the CSF concentrations achieved after intranasal administration were significantly higher than those after intravenous administration. This indicated that the E2-CS-NPs through intranasal route were very much effective in transporting the drug to CSF and thus this system can be used for brain targeting.
Fazil et.al prepared rivastigmine (RHT) loaded chitosan nanoparticles (CS-RHT NPs) by ionic gelation method for treatment of Alzheimer’s disease. The nanoparticles prepared were characterized for both in vitro and in vivo studies. The brain/blood ratio of RHT at 30 mins was highest for CS-RHT NPs as compared to other formulations; which indicates direct nose to brain transport of RHT bypassing the BBB. The brain concentration achieved from i.n. administration of CS-NPs was significantly higher than those achieved after i.v. administration of RHT solution and i.n. administration of RHT solution. The experiment showed promising results
Alam et. al. prepared Chitosan (CS) nanoparticles of thymoquinone (TQ), an active ingredient isolated from Nigella sativa and has been investigated for its anti-oxidant, anti-inflammatory and anticancer activities. The nanoparticles were prepared by the ionic gelation method. They were also subjected to characterization on the basis of in vitro or ex vivo release, surface morphology, X-ray diffractometry (XRD) and dynamic light scattering studies. XRD studies proved that TQ when dispersed in the nanoparticles changed its form from crystalline to amorphous. This finding was further confirmed by differential scanning calorimetry studies. The uptake of drug into the brain from the optimized nanoparticles was ascertained by scintigraphy imaging. Based on Cmax, tmax, AUC over 24 hours, and elimination rate constant, intranasal TQ-loaded nanoparticles (TQNP1) proved more effective in brain targeting compared to intravenous and intranasal TQ solution.
Bromocriptine (BRC) loaded chitosan nanoparticles (CS NPs) were prepared by Khan et. al. by ion gelation process for brain targeting of bromocriptine following intranasal (i.n.) administration. The NPs were of mean size (161.3 ?? 4. 7 nm) and zeta potential (+40.3 ?? 2.7 mV). In vivo studies were carried on mice after inducing Parkinson by oral administration of haloperidol (2mg/kg). Biodistribution of bromocriptine formulations in the blood and brain of mice following i.n. and i.v. administration was done by using technetium labeled (99mTclabeled) as a marker. The brain/blood ratio of BRC-CS-NPs (i.n.) was highest than other formulations and modes of administration which suggests direct nose to brain transport bypassing the blood brain barrier.
In another study, Gulati et. al. prepared sumatriptan succinate loaded chitosan nanoparticles by ionic gelation of chitosan with tripolyphosphate anions (TPP) and Tween 80 as surfactant. The CSNPs had a mean size of 306.8 ?? 3.9 nm, entrapment efficiency of 75.4 ?? 1.1% and zeta potential of +28.79 mV. The authors evaluated in vitro drug release of chitosan nanoparticles in phosphate buffer saline pH 5.5 using goat nasal mucosa. The release of the drug from the nanoparticles showed non-Fickian diffusion which indicates that drug release is controlled by a diffusion-controlled as well as a swelling-controlled release. This is because of the characteristics of chitosan which dissolves at lower pH, thus the nasal pH range supports it very well. The results suggested that sumatriptan succinate-loaded chitosan nanoparticles can have the potential to be a suitable mode of drug delivery.
Sharma et. al. prepared chitosan nanoparticles loaded with levodopa (CNL) and incorporated it in a thermoreversible gel prepared using Pluronic PF127 (CNLPgel). The gelling temperature, gelling time and mucoadhesive strength of CNLPgel were evaluated. The rheological behavior of plain pluronic gel from Newtonian system at 30 ??C was changed to pseudoplastic behavior at 35 ??C on incorporation of CNL. In vitro drug release studies from nanoparticles obeyed Higuchi kinetic model, whereas the drug release from gel followed the Hixson Crowell model.
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