Antimicrobial drug release study from delivery systems for local treatment of periodontal disease using a micro flow-through apparatus

Parodontalna bolezen velja za razširjeno kronično vnetno bolezen ljudi in se razvije zaradi več dejavnikov, zaradi česar je njeno zdravljenje zelo zahtevno. Razvoj novih lokalnih dostavnih sistemov lahko vodi k izboljšanju trenutnega zdravljenja. Za učinkovit razvoj takšnih dostavnih sistemov je dobrodošlo, da jih vrednotimo z metodami, ki čim bolje ponazarjajo pogoje na mestu aplikacije. Tako je bil namen magistrske naloge uporaba mikropretočne naprave, ki posnema pogoje v obzobnem žepu, za vrednotenje dveh lokalnih dostavnih sistemov s protimikrobno učinkovino in primerjava dobljenih profilov sproščanja s profili pridobljenimi s prilagojenim preskusom sproščanja ali literaturnimi podatki o sproščanju in vivo. V okviru magistrske naloge smo izvedli preskus sproščanja z nanovlakni iz hitosana in polietilenoksida z vgrajenim ciprofloksacinom. Poleg nanovlaken smo proučili tudi sproščanje klorheksidina iz komercialno dostopnega dostavnega sistema (PerioChip) za zdravljenje parodontalne bolezni. Koncentracijo sproščenega ciprofloksacina smo vrednotili z metodo UPLC, za detekcijo klorheksidina pa smo razvili in validirali metodo HPLC. Pri vrednotenju sproščanja z mikropretočno napravo smo ugotovili, da se je ciprofloksacin v primeru večje vgradnje (30 %) sproščal počasneje kot v primeru manjše vgradnje (20 %), kar nakazuje na učinkovitejše podaljšano sproščanje nanovlaken s 30 % ciprofloksacina kot v primeru nanovlaken z 20 % ciprofloksacina. V slednjih se je nahajal večji delež protimikrobne učinkovine v amorfni obliki, ki se raztaplja hitreje, zato se je iz nanovlaken z 20 % ciprofloksacina učinkovina sprostila hitreje. Ciprofloksacin je bistveno bolje topen v mediju s pH 1 v primerjavi s topnostjo v mediju s pH 7,4, zato se je v mediju s pH 1 hitreje sproščal kot v mediju s pH 7,4. Opazili smo tudi, da pride v primeru nanovlaken do večjega in hitrejšega začetnega porasta koncentracije zdravilne učinkovine v primerjavi s sproščanjem učinkovine iz PerioChipa. Rezultati kažejo, da PerioChip in nanovlakna s 30 % ciprofloksacinom vzdržujeta podobno koncentracijo zdravilne učinkovine skozi daljše časovno obdobje, kar je značilno za farmacevtske oblike s podaljšanim sproščanjem. V primerjavi z literaturnimi in vivo podatki, se je in vitro iz PerioChipa sprostilo približno desetkrat manj zdravilne učinkovine. Ugotovili smo, da med in vitro rezultati sproščanja klorheksidina iz PerioChipa in literaturnimi in vivo podatki korelacija ne obstaja. Z namenom še večjega posnemanja fizioloških pogojev obzobnega žepa bi bilo v prihodnje mikropretočno napravo smiselno dodelati.Periodontal disease is a chronic inflammatory human disease and develops due to several factors making it difficult to treat. The development of new local delivery systems can lead to an improvement in current treatment. For the effective development of such delivery systems, it is beneficial to evaluate them with methods that best illustrate the conditions at the application site. Thus, the purpose of the master\u27s thesis was to use a micro flow-through apparatus that mimics periodontal pocket to evaluate two local antimicrobial delivery systems and to compare the obtained release profiles with profiles obtained by a modified dissolution test or in vivo release data. As a part of the master\u27s thesis, we performed a drug release test with nanofibers from chitosan and polyethylene oxide with incorporated ciprofloxacin. In addition to nanofibers, we also studied the release of chlorhexidine from a commercially available delivery system (PerioChip) for the treatment of periodontal disease. The concentration of released ciprofloxacin was evaluated by the UPLC method, and the HPLC method was developed and validated for the detection of chlorhexidine. When evaluating the release with a micro-flow through apparatus, we found that ciprofloxacin was released more slowly in the case of higher loading (30 %) than in the case of a lower percentage (20 %) of incorporated ciprofloxacin, indicating more effective prolonged release of nanofibers with 30 % ciprofloxacin than in the case of nanofibers with 20 % ciprofloxacin. The latter contained a larger proportion of the antimicrobial drug in an amorphous form, which dissolves faster, thus the drug release was faster from nanofibers with 20 % ciprofloxacin. Ciprofloxacin is significantly more soluble in medium with pH 1 compared to its solubility in medium with pH 7,4, so it was released more rapidly in pH 1 medium than in pH 7,4 medium. We also observed that in the case of nanofibers, there is a larger and faster initial increase in the concentration of the drug compared to the release of the drug from PerioChip. The results show that PerioChip and nanofibers with 30 % ciprofloxacin maintain a similar concentration of drug for prolonged time, which is characteristic of extended-release dosage forms. Compared to in vivo literature data, approximately ten times smaller amount of the drug was released from PerioChip in vitro. We did not confirm any correlation between the in vitro data of chlorhexidine release from PerioChip and in vivo literature data. In the future it would be reasonable to modify the micro flow-through apparatus in such a way to better simulate the physiological conditions in the periodontal pocket