Brain-targeted glycyrrhizic-acid-loaded surface decorated nanoparticles for treatment of cerebral ischaemia and its toxicity assessment.

OBJECTIVE: Enhancement of CS-GA-PCL-NPs (Glycyrrhizic Acid-encapsulated-chitosan-coated-PCL-Nanoparticles) bioavailability in brain. METHODS: Double emulsification solvent evaporation method in order to develop CS-PCL-NPs (Chitosan-coated-PCL-Nanoparticles) followed by characterization of particle size and distribution, zeta potential, encapsulation efficiency and drug release (in vitro). To determine drug-uptake and its pharmacokinetic profile in brain as well as plasma, UHPLC (triple quadrupole Q-trap) MS/MS method was developed and optimized for CS-GA-PCL-NPs as well as to follow-up examined effective role of optimized NPs in reduction of all brain injury parameters after MCAO through the grip strength, locomotor activity, inflammatory cytokines levels, measurement of infarction volume and histopathological changes in neurons with safety/toxicity after i.n. in animals. RESULTS: The developed NPs showed an average particle size, entrapment efficiency with PDI (polydispersity index) of 201.3 ± 4.6 nm, 77.94 ± 5.01% and 0.253 ± 0.019, respectively. Higher mucoadhesive property for CS-GA-PCL-NPs as compared to conventional and homogenized nanoformulations was observed whereas an elution time of 0.37 min and m/z of 821.49/113.41 for GA along with an elution time of 1.94 min and m/z of 363.45/121.40 was observed for hydrocortisone i.e. Internal standard (IS). Similarly, %CV i.e. inter and intra assay i.e. 0.49-4.41%, linear dynamic range (10-2000 ng/mL) and % accuracy of 90.00-99.09% was also observed. AUC0-24 with augmented Cmax was noted (**p < .01), in Wistar rat brain as compared to i.v. treated group during pharmacokinetics studies. In MCA-occluded rats, enhanced neurobehavioral activity i.e. locomotor and grip strength along with a decrease in cytokines level (TNF-α and IL-1ß) was observed, following i.n. administration. CONCLUSIONS: CS-coated-GA-loaded-PCL-NPs when administered i.n. enhanced the bioavailability of the drug in rat brain as compared to i.v. administration. The observation from toxicity study concludes; the developed NPS are safe and free of any health associated risk.

Intranasal delivery of quercetin-loaded mucoadhesive nanoemulsion for treatment of cerebral ischaemia.

BACKGROUND: Quercetin (QUR), as an antioxidant flavonoid, exhibits potential role in the amelioration of cerebral ischaemia; however, poor solubility as well as oral absorption results low serum and tissue levels for this drug. PURPOSE OF THE STUDY: To enhance bioavailability, this study aims to prepare QUR nanoemulsions and administer via non-invasive nasal route in order to evaluate the drug targeting in brain. METHODS: Quercetin mucoadhesive nanoemulsion (QMNE) was prepared (ionic gelation method) and optimized using various parameters, that is, particle size, entrapment efficiency, zeta potential and ex vivo permeation study. RESULTS: The results observed for optimized QMNE were as follows: mean globule size (91.63 ± 4.36 nm), zeta potential (-17.26 ± 1.04 mV), drug content (99.84 ± 0.34%) and viscosity (121 ± 13 cp). To evaluate the extent of bioavailability for QMNE via post-intranasal (i.n.) administration, Ultra performance liquid chromatography-mass spectroscopy (UPLC-ESI-Q-TOF-MS/MS)-based bioanalytical method was developed and validated for pharmacokinetics, biodistribution, brain-targeting efficiency (9333.33 ± 39.39%) and brain drug-targeting potential (2181.83 ± 5.69%) which revealed enhanced QUR brain bioavailability as compared to intravenous administration (i.v.). Furthermore, improved neurobehavioral activity (locomotor and grip strength), histopathology and reduced infarction volume effects were observed in middle cerebral artery occlusion (MCAO)-induced cerebral ischemic rats model after i.n. administration of QMNE. CONCLUSION: This study supports a significant role for QMNE in terms of high brain-targeting potential and formulation efficiency due to ease of access and effective targeting in brain.

Enhancement of Quercetin Oral Bioavailability by Self-Nanoemulsifying Drug Delivery System and their Quantification Through Ultra High Performance Liquid Chromatography and Mass Spectrometry in Cerebral Ischemia.

Background Quercetin (Qur) and its major in vivo bioactive metabolites i. e., 3'-O-methyl quercetin, 4'-O-methyl quercetin and quercetin 7-O-ß-D-glucuronide, may be used to treat cerebral ischemia however the poor aqueous solubility and less intestinal absorption of Qur results low bioavailability. Purpose To improve Qur bioavailability through preparation of nanoformulation and to develop and validate a sensitive quantification method for Qur detection in brain homogenate. Methods Qur-containing self-nanoemulsifying drug delivery system (Qur-SNEDDS) was developed to form oil-in-water nanoemulsions in situ. Ultra-high performance liquid chromatography electrospray ionization-synapt mass spectrometric method (UHPLC/ESI-QTOF-MS/MS) was developed and validated for quantification whereas for optimal recovery of analyte, a liquid-liquid extraction method (LLE) was used. Results A droplet size of 94.63±3.17 nm and zeta potential of -17.91±1.02 mV for nanoemuslion, elution time for Qur and internal standard (IS) Rutin as 1.21 and 1.50 min alongwith a transition at m/z 301.04/151.03 and 609.21/299.21, were observed respectively. Similarly, linear dynamic range (1.00 ng/mL-2 000.0 ng/mL), intra and inter-assay i. e., %CV of 0.26-2.04, lower limit of detection (LOD) 0.08 ng/mL as well as lower limit of quantitation (LOQ) as 0.131 ng/mL were also observed. Conclusion The developed method have advantage over previous all methods i. e., less time consuming (<3.0), low consumption of solvents (flow rate 0.20 mL/min.) via small size column, more accuracy and specificity as well as use of acetonitrile as compared to hazardous solvents. This certainly adds advantages for green chromatography technique and supports application of current developed method for quantification and evaluation of Qur-SNEDDS.