Selektivnost voltametrijske metode za istovremeno određivanje pimavanserina i levodope

master's thesis

• Title (english): Selectivity of the voltammetric method for the simulataneous determination of pimavanserin and levodopa
• Author: Petar Fuš
• Mentor: Biljana Nigović (mentor)
• Committee member: Biljana Nigović (predsjednik povjerenstva)
• Committee member: Miranda Sertić (član povjerenstva)
• Committee member: Sandra Jurić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmaceutical analysis); Zagreb
• Defense date and country: 2022-09-02, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Pimavanserin je antipsihotik s velikim potencijalom u liječenju deluzija i halucinacija u Parkinsonovoj bolesti, vrlo čestoj kroničnoj neurodegenerativnoj bolesti. Svrha ovog rada bila je ispitivanje selektivnosti voltametrijske metode prilikom istovremenog određivanja pimavanserina i levodope u kombinaciji s različitim lijekovima i tvarima. Za ispitivanje je odabrana pravokutnovalna voltametrijska tehnika, a mjerenja su napravljena na površini elektrode od staklastog ugljika koja je modificirana nanomaterjalima (smjesa grafenovih nanopločica i grafitiziranih višeslojnih ugljikovih nanocjevčica 1:1, koncentracije 1 mg/mL, u 0,3% Nafionu), uz prethodno pretkoncentriravanje analita tijekom 60 sekundi, pri frekvenciji 75 Hz, amplitudi pulsa od 20 mV i porastu potencijala 4 mV. Ispitivanjem je ustanovljeno kako pimavanserin i levodopa međusobno ne interferiraju pri mjerenju novom voltametrijskom metodom. Strujni vrh pimavanserina nalazio se pri vrijednosti potencijala od 1,07 V, a strujni vrh levodope pri 0,37 V. Utvrđena su i područja linearnosti za oba lijeka. Tvari koje se mogu pronaći u tjelesnim tekućinama, kao što su glukoza, natrijev klorid, kalijev klorid, karbonati, fosfati i mokraćna kiselina, ne smetaju prilikom istovremenog određivanja pimavanserina i levodope. Neki lijekovi kao što su kvetiapin i ropinirol smetaju u određivanju pimavanserina, budući da su im oksidacijski vrhovi preblizu oksidacijskom vrhu pimavanserina i s njime interferiraju. Oksidacijski pik dopamina opažen pri 0,37 V nije utjecao na mogućnost određivanja pimavanserina, ali jest na određivanje levodope pri koncentraciji većoj od 5x10-7 mol/dm3, što je značajno više od njegove očekivane koncentracije u serumu. Entakapon u mjerenjima nije utjecao na mogućnost određivanja pimavanserina i levodope, budući da njegov strujni vrh na potencijalu 0,54 V ne interferira ni sa strujnim vrhom pimavanserina niti sa strujnim vrhom levodope.

Abstract (english)

Pimavanserin is an antipsychotic with great potential in the treatment of delusions and hallucinations in Parkinson's disease, a very common chronic neurodegenerative disease. The aim of these thesis was examination of selectivity of votammetric method during simultaneous determination of pimavanserin and levodopa in combination with different drugs and substances. For examination was chosen square wave voltammetry technique, and the measurements were made on the surface of glassy carbon electrode, which was modified with nanomaterials (mixture of graphene nanoplates and graphitized multi-walled carbon nanotubes 1:1, concentration of 1 mg/mL, in 0,3% Nafion), with previous preconcentration of analyte for 60 seconds, at the frequency of 75 Hz, with pulse amplitude of 20 mV and increase of potential of 4mV. Determination have proven that pimavanserin and levodopa don't interfere with each other when they are measured with new voltammetric method. Pimavanserin shown current peak at potential of 1,07 V, and levodopa shown current peak at 0,37 V. Linearity ranges for both drugs were also determined. Substances that can be found in body liquids, such as glucose, sodium chloride, potassium chloride, carbonates, fosfates and uric acid, do not interfere in simultaneously determination with pimavanserin and levodopa. Some medications such as quetiapine and ropinirole interfere in determination of pimavanserin, because their oxidation peaks are too close to oxidation peak pimavanserin and with it they interfere. Oxidation peak of dopamine observed at 0,37 V din't affect on possibillity of determination of pimavanserin, but it interfere with possibillity of determination of levodopa at concentration higher than 5x10-7 mol/dm3 , what is significantly higher than expected serum concentration. In the measurements, entacapone did not affect the ability to determine pimavanserin and levodopa, since its current peak at a potential of 0.54 V doesn't interfere with the current peak of pimavanserina or the current peak of levodopa.

• Keywords: pimavanserin; levodopa; pravokutnovalna voltametrija; selektivnost; elektroda modificirana nanomaterjalima; stripping voltametrija
• Keywords (english): pimavanserin; levodopa; square wave voltammetry; selectivity; nanomaterial-modified electrode; stripping voltammetry
• Language: croatian
• URN:NBN: urn:nbn:hr:163:095747
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2024-09-02
• Created on: 2022-09-09 13:57:36