Razvoj biorelevantne metode ispitivanja in vitro oslobađanja metaksalona iz tableta trenutnog oslobađanja

doctoral thesis

• Title (english): Biorelevant dissolution method development for metaxalone immediate release tablets
• Author: Lucija Vuletić
• Mentor: Biserka Cetina-Čižmek (mentor)
• Mentor: Jelena Filipović-Grčić (komentor)
• Mentor: Maja Lusina Kregar (komentor)
• Committee member: Jasmina Lovrić (predsjednik povjerenstva)
• Committee member: Mila Lovrić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmaceutical technology); Zagreb
• Defense date and country: 2019-07-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy
• Universal decimal classification (UDC): 615 - Pharmacology. Therapeutics. Toxicology

Abstract

Vrlo važan korak tijekom razvoja novog lijeka jest kreiranje klinički relevantne in vitro metode oslobađanja
lijeka. Tijekom razvoja lijeka studije bioraspoloživosti lijeka in vivo mogu zamijeniti ispitivanjem oslobađanja
lijeka in vitro ako je uspostavljen matematički model koji opisuje odnos između profila oslobađanja lijeka in
vitro i odgovora in vivo (koncentracija lijeka u plazmi ili frakcija apsorbiranog lijeka) koji se naziva in vitro – in
vivo korelacija (IVIVC).
Cilj je ovog rada klasificirati metaksalon prema biofarmaceutskoj klasifikaciji lijekova (BCS), razviti klinički
relevantnu in vitro metodu oslobađanja lijeka i uspostaviti IVIVC model.
Topljivost lijeka ispitivana je pri različitim pH vrijednostima medija, a permeabilnost je provedena na Caco-2
staničnome modelu. Testovi oslobađanja in vitro provedeni su s trima različitim formulacijama tableta s
trenutačnim oslobađanjem metaksalona uz primjenu aparature tipa 2. Iste su formulacije tableta i oralna otopina
metaksalona korištene u bioekvivalencijskoj studiji in vivo na zdravim ispitanicima u randomiziranom,
ukriženom pokusu. IVIVC je uspostavljen metodom utemeljenom na diferencijalnim jednadžbama.
Dobiveni su rezultati potvrdili da metaksalon prema klasifikaciji lijekova BSC pripada klasi 2. Provedena
bioekvivalencijska studija potvrdila je da je oslobađanje lijeka ključan korak koji utječe na bioraspoloživost i
jedna je ispitivana formulacija tableta imala značajno veću bioraspoloživost od referentne formulacije. Najviši
stupanj korelacije postignut je primjenom metode s acetatnim puferom pH 4,5 uz dodatak 0,5 % natrijeva klorida
i 0,2 % natrijeva laurilsulfata (USP aparatura 2, 50 okr./min) kao medijem za oslobađanje lijeka in vitro.
Validacijom modela utvrđena je njegova prihvatljiva pogreška, čime je potvrđena točnost predviđanja
razvijenoga IVIVC modela.
Ta spoznaja omogućuje optimizaciju formulacija tableta metaksalona i izbjegavanje nepotrebnih ispitivanja
neadekvatnih formulacija na zdravim dobrovoljcima. Identificirani in vitro medij može poslužiti za razvoj
generičkog lijeka drugih molekula sličnih fizikalno-kemijskih svojstava. U ovom je radu IVIVC model
uspostavljen izravnom metodom utemeljenom na diferencijalnim jednadžbama, koji se može primijeniti kao
alternativni model za uspostavu IVIVC-a lijekova BCS klase 2 s trenutačnim oslobađanjem.

Abstract (english)

An important step during drug development process is design of a clinically relevant in vitro drug release
dissolution method. In vitro testing may serve as a surrogate for in vivo bioavailability study if in vitro-in vivo
correlation (IVIVC), a predictive mathematical model describing the relationship between an in vitro property of
a dosage form and relevant in vivo response (plasma drug concentration or fraction of the absorbed drug) is
established.
The aim of the present work was to classify metaxalone according to the Biopharmaceutics Classification
System (BCS), to develop a clinically relevant dissolution method that can be used to predict the oral absorption
of metaxalone and to establish an in vitro-in vivo correlation (IVIVC).
Solubility of the drug was studied in different pH media and permeability studies were performed using a Caco-2
cell model. The in vitro dissolution and in vivo disposition of metaxalone from 3 different immediate release (IR)
tablet formulations were investigated using USP 2 apparatus and a single dose, four-way, crossover
bioequivalence study in healthy humans along with an oral solution of the drug, respectively. An IVIVC was
established by using a direct, differential based method.
Metaxalone has been confirmed as a Class 2 drug according to BCS. Bioavailability studies performed in
humans demonstrated that dissolution was the rate limiting step for bioavailability of the drug and one of the test
products had significantly improved bioavailability compared to the marketed product. A highest level of
correlation with in vivo data was established with the in vitro data obtained in pH 4.5 dissolution medium
containing 0.5% NaCl with 0.2% SLS (USP apparatus 2 at 50 rpm). An IVIVC model validation was performed
and demonstrated an acceptable internal predictability.
Based on these findings, it is possible to further optimize the development of metaxalone tablets and to avoid
unnecessary testing of inadequate formulations on healthy volunteers, the identified in vitro medium can serve in
the generic development of other molecules of similar physical-chemical characteristics. In this work the IVIVC
model based on the direct differential equation method can be used as an alternative IVIVC model for BCS class
2 drugs with immediate release.

• Keywords: metaksalon; topljivost; apsorpcija na Caco-2 staničnom modelu; in vitro metoda oslobađanja lijeka
• Keywords (english): metaxalone; solubility; Caco-2 cell absorption; dissolution method
• Language: croatian
• URN:NBN: urn:nbn:hr:163:667584
• Study programme: Title: Pharmacy and biochemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor znanosti (doktor znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-10-14 12:12:35