1. Formulation and evaluation of thermoreversible, mucoadhesive in situ intranasal gel of rizatriptan benzoate
Amolkumar Kempwade • Ashok Taranalli. J Sol-Gel Sci Technol (2014) 72:43–48
Rizatriptan benzoate is a selective 5-hydroxytryptamine (5-HT) 1B/1D receptor agonist commonly prescribed for treatment of migraine. Theories on the etiology of migraine suggest that symptoms are due to local cranial vasodilatation and/or due to the release of vasoactive and pro-inﬂammatory peptides from sensory nerve ending in an activated trigeminal system. Rizatriptan benzoate has been shown to relieve migraine within 2 h in 70–80 % of patients. Oral bioavailability of rizatriptan benzoate is 40–45 %. Rizatriptan benzoate undergoes extensive hepatic metabolism by monoamine oxidase A isoenzyme (MAO-A) to an inactive indole acetic acid metabolite. Various approaches like orodispersible tablets, mucoadhesive buccal ﬁlms, elastic liposome based transdermal drug delivery system have been tried to overcome this problem. The intranasal route has been considered as a viable alternative for drugs which have extensive ﬁrst pass metabolism. This route is also having an added advantage of direct delivery of drug to brain via olfactory route when the site of action is in brain. In one study, drug was administered as nasal spray but the bioavailabilitywas found to be 43 ± 7 %. This ismainly due to clearance of drug from nasal cavity due to mucociliary clearance. There is need to develop such a formulationwhich will remain inside the nasal cavity for longer time. In order to remain the formulation inside the nasal cavity for longer time it should have sufﬁcient viscosity and mucoadhesive strength so that it cannot be easily drained off, at the same time it should be easily pourable to instill the required dose in nasal cavity.
2. A Comparative Study of Orally Delivered PBCA and ApoE Coupled BSA Nanoparticles for Brain Targeting of Sumatriptan Succinate in Therapeutic Management of Migraine
Priti Girotra & Shailendra Kumar Singh. Pharm Res.
A simple liquid-liquid extraction process was then followed for the extraction of drug from plasma and brain samples. To 200 μl each of plasma and brain samples in a test tube, 200 μl 2 M NaOH and 20 μl of rizatriptan benzoate (100 μg/ml) as an internal standard for HPLC testing were added. After vortexing it for 1 min, 2 ml ethyl acetate was added, with shaking for 2 min and then centrifuging at 8000 rpm for 15 min at 10°C. The extraction step was repeated twice to ensure complete extraction of the drug from the samples. The extracts were mixed followed by evaporation to dryness and reconstituted with 200 μlmobilephase used for HPLC analysis.