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Acetylsalicylic acid belongs to nonsteroidal anti-inflammatory drugs with antiinflammatory, analgesic and antipyretic properties. The aim of this work was development and validation of HPLC method for qualitative and quantitative analysis of acetylsalicylic acid and its major degradation product, salicylic acid, in dosage forms. The optimal separation was achived using Zorbax Eclipse XDB-C18 Analytical column (4,6x150 mm, particle size 5 μm) thermostated at 35°C. Mobile phase consisted of eluents A and B in ratio 65:35 (V/V). As the eluent A, water of HPLC purity and 85% phosphoric acid in ratio 80:0.5 (V/V) were used, while acetonitrile was used as the eluent B. The flow rate was 1.0 mL/min and UV detection was performed at 240 nm. The method was validated in terms of selectivity, linearity, precision, accuracy and robustness for both analytes, as well as limits of detection and quantification for salicylic acid. The obtained results meet the requirements of analytical procedures validation. The proposed HPLC method was applied in qualitative and quantitative analysis of acetylsalicylic and salicylic acids in six different forms of drugs. All obtained results meet the requirements of manufacturer specifications. The established HPLC method was found to be rapid, simple, accurate and selective for simultaneous determination of acetylsalicylic and salicylic acids in dosage forms., Acetilsalicilna kiselina pripada grupi nesteroidnih antiinflamatornih lekova koji ispoljavaju antiinflamatorno, analgetičko i antipiretičko delovanje. Cilj ovog rada je bio razvoj i validacija HPLC metode za kvalitativnu i kvantitativnu analizu acetilsalicilne kiseline i njenog degradacionog proizvoda, salicilne kiseline, u doziranim oblicima. Optimalno razdvajanje ispitivanih analita postignuto je na koloni Zorbax Eclipse XDB-C18 Analytical (4,6x150 mm, veličina čestica 5 μm) na temperaturi od 35°C. Mobilnu fazu čine smeša A i B u odnosu 65:35 (V/V). Smeša A je voda HPLC čistoće i 85% fosforna kiselina u odnosu 80:0,5 (V/V), a B je acetonitril. Protok je bio 1,0 mL/min, a talasna dužina detekcije 240 nm. Metoda je validirana i ispitani su sledeći parametri validacije: selektivnost, linearnost, preciznost, tačnost i robusnost za oba analita, kao i limiti detekcije i kvantifikacije za salicilnu kiselinu. Dobijene vrednosti su u skladu sa definisanim kriterijumima za validaciju metode. Predložena HPLC metoda je primenjena za kvalitativnu i kvantitativnu analizu acetilsalicilne i salicilne kiseline u šest različitih komercijalnih preparata. Svi rezultati ispitivanja su u dozvoljenim granicama specifikacija proizvođača. Predložena HPLC metoda pod datim eksperimentalnim uslovima predstavlja brz, jednostavan, tačan i selektivan postupak za istovremeno određivanje acetilsalicilne i salicilne kiseline u doziranim oblicima.

Type 2 diabetes is a metabolic syndrome characterized by relative insulin deficiency, insulin resistance and increased hepatic glucose output. Medications used to treat the disease (hypoglycemic agents) are divided in seven distinct classes. One of those classes, thiazolidindiones ('glitazones'), are known as insulin sensitizers and act mainly by improving peripheral uptake and utilization of glucose in muscle and fat, finally decreasing liver glucose production. These drugs activate one or more peroxisome proliferator-activated receptors (PPARs), which regulate gene expression in response to ligand binding. The thiazolidindiones differ by the nature of the groups attached to the 2,4-thiazolidindione nucleus. These agents are extensively metabolized with all metabolic changes occurring on thiazolidine ring or adjacent aryl group. Considerable interest in the metabolism of troglitazone exists, because hepatic toxicity may be associated with a quinone-type metabolite of troglitazone. Thiazolidindiones (rosiglitazone and pioglitazone) have been approved for monotherapy and combination therapy with metformin, sulfonylureas or insulin. Unfortunately, some studies and metaanalyses suggested that both drugs improve a number of cardiovascular risk factors and enhance incidence of heart failure., Dijabetes tipa 2 je metaboličko oboljenje koje karakteriše relativni nedostatak insulina, rezistencija na insulin i povećano oslobađanje glukoze iz jetre. Lekovi koji se koriste u terapiji ovog oboljenja (hipoglikemici) mogu se klasifikovati u sedam različitih grupa. Tiazolidindioni (glitazoni) povećavaju osetljivost na insulin, preuzimanje i potrošnju glukoze u mišićima i masnom tkivu, a sve to utiče na smanjeno oslobađanje glukoze iz jetre. Ovi lekovi su agonisti PPAR receptora (receptori aktivirani proliferatorom peroksizoma) i dovode do transkripcije gena uključenih u metabolizam glukoze i lipida. Tiazolidindioni se međusobno razlikuju po strukturi supstituenata na 2,4-tiazolidindionu. Podležu intenzivnom metabolizmu u jetri, sa svim metaboličkim promenama na tiazolidinskom prstenu ili susednoj aril grupi. Postoji veliko interesovanje za metabolizam troglitazona, jer se njegova hepatotoksičnost povezuje sa metabolitom troglitazona tipa hinona. Tiazolidindioni (rosigltazon i pioglitazon) su odobreni kao monoterapija ili u kombinaciji sa metforminom, derivatima sulfonilureje ili insulinom. Nažalost, novija istraživanja i meta-analize ukazale su na to da oba leka povećavaju faktore kardiovaskularnog rizika i učestalost srčane insuficijencije.

Today with the development of combinatorial chemistry hundreds and hundreds of compounds that have potential biological activity are synthesized. The studies which include the selection of drug candidates and the study of their pharmacological properties are time consuming, expensive and usually require the use of experimental animals. For ethical and/or economical reasons, a great deal effort is currently being made to develop in vitro systems and provide primary information about the capability of new compounds in the first steps of drug development. Chromatographic models to predict drug absorption are experimentally easier than membrane-based permeability assays, because of their simplicity, accuracy and avoidance of experimental animals. Different chromatographic systems have been proposed to predict oral drug absorption. The use of conventional reversed-phase columns only has proven to provide adequate correlations for homologous series of compounds. The inclusion of amphiphilic structures in the stationary and/or mobile phases is a pre-requisite to emulate interactions of drugs with the phospholipids bilayers in the membranes., Savremeni razvoj kombinatorijalne hemije omogućio je sintezu velikog broja jedinjenja sa potencijalnom biološkom aktivnošću. Ispitivanja koja uključuju izbor jedinjenja i studije farmakoloških osobina su dugotrajna, skupa i obično zahtevaju primenu eksperimentalnih životinja. Iz etičkih i/ili ekonomskih razloga, veliki napori ulažu se u razvoj in vitro sistema koji mogu da pruže značajne informacije u ranim fazama razvoja leka. Hromatografski modeli za predviđanje apsorpcije leka su eksperimentalno jednostavni, tačni i ne zahtevaju primenu eksperimentalnih životinja. Primena reverznofaznih hromatografskih sistema dala je dobre korelacije samo za homologe serije jedinjenja. Uvođenje amfifilnih struktura u stacionarnu i/ili mobilnu fazu je bitan uslov za simulaciju interakcija farmakološki aktivnih jedinjenja sa fosfolipidnim dvoslojem u membrani.

Soft ('antedrug') glucocorticoids are pharmacologically active compounds which are biotransformed in a predictable and controllable way to inactive and non-toxic metabolites. Amides of cortienic acids (17(-carboxamide derivatives of glucocorticoids) are potential soft drugs with fewer side effects than traditional glucocorticoids. The purification of 17(- carboxamide derivatives of hydrocortisone was explained using the amide of hydrocortisonederived cortienic acid and ethyl ester of L-glycine as an example and performed by use of column chromatography and preparative thin-layer chromatography (TLC). The optimization of purification process was performed employing analytical TLC and reversed-phase highperformance liquid chromatography (RP-HPLC). The mobile phase that enables best chromatographic separation of the amide from impurities on TLC plate (chloroform-methanol (95:5 V/V)) was selected and modified (reduction of polarity and addition of glacial acetic acid) to be used for the column chromatography and preparative TLC purification. It was confirmed by use of RP-HPLC that purification procedures applied in this study resulted in pure (96.2 %) amide., Soft ('antedrug') glukokortikoidi su farmakološki aktivna jedinjenja koja se biotransformišu na predvidiv i kontrolisan način do neaktivnih i netoksičnih metabolita. Amidi kortienskih kiselina (17(-karboksamidni derivati glukokortikoida) su potencijalni soft lekovi sa manje neželjenih efekata u odnosu na konvencionalne glukokortikoide. Prečišćavanje 17(- karboksamidnih derivata hidrokortizona je prikazano na primeru amida kortienske kiseline iz hidrokortizona i etil estra L-glicina i vrši se primenom hromatografije na koloni i preparativne tankoslojne hromatografije (TLC). Optimizacija procesa prečišćavanja je izvršena primenom analitičke TLC i reverzno-fazne tečne hromatografije pod visokim pritiskom (RP-HPLC). Mobilna faza koja omogućuje najbolje hromatografsko razdvajanje amida od nečistoća na TLC pločici (hloroform-metanol (95:5 V/V) je odabrana i izvršena je njena modifikacija (smanjenje polarnosti, odnosno dodatak glacijalne sirćetne kliseline) u cilju prečišćavanja hromatografijom na koloni, odnosno preparativnom TLC. Primenom RP-HPLC je potvrđeno da su navedeni postupci prečišćavanja omogućili dobijanje amida stepena čistoće 96,2 %.