Design, synthesis and biological evaluation of novel primaquine-cinnamic acid conjugates of the amide and acylsemicarbazide type

In this paper design and synthesis of a scaffold comprising primaquine (PQ) motif and cinnamic acid derivatives (CADs) bound directly (compounds 3a–k) or via a spacer (compounds 7a– k) are reported. In the first series of compounds, PQ and various CADs were connected by amide bonds and in the second series by acylsemicarbazide functional groups built from the PQ amino group, CONHNH spacer and the carbonyl group originating from the CADs. PQ- CAD amides 3a–k were prepared by a simple one- step condensation reaction of PQ with a series of CAD chlorides (method A) or benzotriazolides 2 (method B). The synthesis of acylsemicarbazides 7a–k included activation of PQ with benzotriazole, preparation of PQ- semicarbazide 6 and its condensation with CAD chlorides 4. All synthesized PQ-CAD conjugates were evaluated for their anticancer, antiviral and antioxidative activities. Almost all compounds from series 3 were selective towards the MCF-7 cell line and active at micromolar concentrations. The o-fluoro derivative 3h showed high activity against HeLa, MCF-7 and in particular against the SW 620 cell line, while acylsemicarbazide 7f with a benzodioxole ring and 7c, 7g and especially 7j with methoxy-, chloro- or trifluoromethyl-substituents in the para position showed high selectivity and high inhibitory activity against MCF-7 cell line at micromolar (7c, 7f, 7g) and nanomolar (7j) levels. Acylsemicarbazide derivatives with trifluoromethyl group(s) 7i, 7j and 7k showed specific activity against human coronavirus (229E) at concentrations which did not alter the normal cell morphology. The same compounds exerted the most potent reducing activity in the DPPH test, together with 7d and 7g, while methoxy (compounds 7c–e), benzodioxole (7f), p- Cl (7g) and m-CF3 (7i) acylsemicarbazides and amide 3f presented the highest LP inhibition (83%–89%). The dimethoxy derivative 7d was the most potent LOX inhibitor (IC50 = 10 μΜ). The performed biological tests gave evidence of acylsemicarbazide functional group as superior binding group in PQ-CAD conjugates

Development of an in vitro release method for an oily formulation of dexamethasone with addition of isopropanol

Uljne otopine jednostavni su tekući farmaceutski oblici koji pružaju mogućnost parenteralne primjene djelatnih tvari (API, eng. active pharmaceutical ingredient) slabo topljivih ili nestabilnih u vodenim medijima. Osim toga, uljne otopine su tip formulacije iz kojih je oslobađanje API produljeno, čime se omogućuje značajno manja učestalost doziranja lijekova, koja je osobito prikladna za terapiju kroničnih bolesti, kao i bolesti kod kojih je adherencija pacijenata varijabilna. Među trenutno razvijenim metodama za ispitivanje oslobađanja djelatnih tvari in vitro ne postoji standardizirana metoda za analizu oslobađanja in vitro iz uljnih otopina. U ovom radu opisan je razvoj jedne takve analitičke metode, korištenjem jednostavne i široko dostupne aparature s lopaticom (USP II) i dijalizacijskih vrećica. Kao modelni lijek za razvoj analitičke metode odabran je potentni glukokortikoid deksametazon, čija je topljivost ispitana u pet biljnih ulja te njihovim kombinacijama s izopropanolom u ulozi suotapala. Izopropanol zasad nije primijenjen kao suotapalo u uljnim otopinama, a u ovom istraživanju pokazao se kao dobro suotapalo. Najveća topljivost deksametazona izmjerena je u smjesi ricinusovog ulja i izopropanola u volumnom udjelu 20 %, a prividni particijski koeficijent deksametazona iz te otopine ima vrijednost koja upućuje na potencijal produljenog oslobađanja iz formulacije, pa je ona odabrana kao modelna formulacija za razvoj metode. Za analizu količine oslobođenog deksametazona korištena je spektrofotometrija potpomognuta optičkim vlaknima, kojom je omogućena potpuna automatiziranost metode te osigurano zadovoljavanje uvjeta osigurane topljivosti tijekom ispitivanja, koji se ne mogu poremetiti jer, zahvaljujući probi optičkog vlakna koja je uronjena u medij za oslobađanje tijekom cijelog ispitivanja, uzorkovanje medija tijekom analize nije potrebno. Razvijena metoda pokazala se osjetljivom prema ključnim parametrima koji se mogu promijeniti in vitro ili tijekom procesa proizvodnje (temperatura i brzina miješanja medija) te je zadovoljavajuće ponovljivosti, jednostavna i potpuno automatizirana. Zbog toga, razvijena metoda mogla bi se koristiti za analizu oslobađanja in vitro djelatnih tvari iz uljnih otopina tijekom predformulacijskih istraživanja, kao i razvoja novih formulacija.Oily solutions are simple liquid dosage forms which allow parenteral application of active pharmaceutical ingredients (API) that are poorly soluble or unstable in aqueous systems. Additionally, release of APIs from these formulations is extended, which makes their application significantly less frequent. This property makes oily solutions especially suitable for the treatment of chronic diseases, as well as diseases characterised by variable patient adherence. Among the currently developed in vitro release methods, there are no standardised methods for the analysis of drug release in vitro from oily solutions. This paper describes the development of such method using the simple and widely available paddle apparatus (USP II) with addition of dialysis bags. The potent glucocorticoid dexamethasone was chosen as the model drug for the development of this method. Solubility of dexamethasone was examined in five vegetable oils and their mixtures with isopropanol as a cosolvent. Isopropanol has not yet been used as a cosolvent in oily solutions, but has demonstrated good solubilization properties. The highest solubility of dexamethasone was measured in the mixture of castor oil and isopropanol in a volume percentage of 20 %, with an apparent partition coefficient indicating a potential for extended release of dexamethasone from this formulation, which was consequently chosen as the model formulation for the development of this in vitro release method. Optic fiber assisted UV-Vis spectrophotometry was used to determine the amount of released dexamethasone. This setup enabled complete automatization of the in vitro release method with ensured sink conditions throughout the experiment, as there was no need to sample the release medium due to the fact that the fiber optic probe is immersed in the dissolution medium for the whole duration of the experiment. The developed in vitro release method has shown appropriate sensitivity regarding parameters that might change in vitro or during the manufacturing process (temperature and agitation rate), as well as satisfactory repeatability, simplicity and complete automatization. Therefore, the developed method can be a useful tool for the analysis of in vitro release from oily solutions during preformulation investigations as well as development of new formulations

Prenamjena lijekova kao strategija u razvoju novih lijekova

As costs for the drug discovery and development rise, alternative paths to new drugs are being investigated. Drug recycling and repurposing present useful approach in getting the drug to the market. Drugs which are recycled for new indications have already gone through the 1 st phase of clinical trials, which significantly reduces time and money needed for the development, as they can go to the 2nd phase of clinical trials directly. Here we describe examples depicting drug recycling in the drug development process

Development of fiber optic in vitro release testing method for dexamethasone release from the oil solutions

For many parenteral drugs, there is still no standardized method for in vitro release (IVR) testing available. This article presents the development of a new IVR method for oil solutions using a dialysis membrane and USP II apparatus coupled to a fiber optic UV-Vis spectrometer. Experiments were performed using dexamethasone formulations containing castor oil as a solvent with the addition of cosolvents, 20 % (v/v) of isopropanol or Capryol® 90. Based on solubility testing results, castor oil was chosen as the best solvent amongst other vegetable oils, while a significant increase in solubility was obtained by adding either of the two cosolvents. Partitioning experiments were performed to ensure these formulations could achieve prolonged drug release. IVR testing was performed with model formulations and critical test parameters were varied in order to examine the method’s sensitivity. The developed method was sensitive to temperature and stirring rate, while coupling the USP II apparatus with a fiber optic UV-Vis spectrometer enabled complete automation. Moreover, due to the interference of excipients on fiber optic detection of dexamethasone during the release testing, derivative spectroscopy was successfully introduced for the elimination of the interference. The developed IVR method described herein could be useful in preformulation investigations and the early development of novel formulations

Design, synthesis and biological evaluation of novel primaquine-cinnamic acid conjugates of the amide and acylsemicarbazide type

In this paper design and synthesis of a scaffold comprising primaquine (PQ) motif and cinnamic acid derivatives (CADs) bound directly (compounds 3a-k) or via a spacer (compounds 7a-k) are reported. In the first series of compounds, PQ and various CADs were connected by amide bonds and in the second series by acylsemicarbazide functional groups built from the PQ amino group, CONHNH spacer and the carbonyl group originating from the CADs. PQ-CAD amides 3a-k were prepared by a simple one-step condensation reaction of PQ with a series of CAD chlorides (method A) or benzotriazolides 2 (method B). The synthesis of acylsemicarbazides 7a-k included activation of PQ with benzotriazole, preparation of PQ-semicarbazide 6 and its condensation with CAD chlorides 4. All synthesized PQ-CAD conjugates were evaluated for their anticancer, antiviral and antioxidative activities. Almost all compounds from series 3 were selective towards the MCF-7 cell line and active at micromolar concentrations. The o-fluoro derivative 3h showed high activity against HeLa, MCF-7 and in particular against the SW 620 cell line, while acylsemicarbazide 7f with a benzodioxole ring and 7c, 7g and especially 7j with methoxy-, chloro- or trifluoromethyl-substituents in the para position showed high selectivity and high inhibitory activity against MCF-7 cell line at micromolar (7c, 7f, 7g) and nanomolar (7j) levels. Acylsemicarbazide derivatives with trifluoromethyl group(s) 7i, 7j and 7k showed specific activity against human coronavirus (229E) at concentrations which did not alter the normal cell morphology. The same compounds exerted the most potent reducing activity in the DPPH test, together with 7d and 7g, while methoxy (compounds 7c-e), benzodioxole (7f), p-Cl (7g) and m-CF₃ (7i) acylsemicarbazides and amide 3f presented the highest LP inhibition (83%-89%). The dimethoxy derivative 7d was the most potent LOX inhibitor (IC50 = 10 μΜ). The performed biological tests gave evidence of acylsemicarbazide functional group as superior binding group in PQ-CAD conjugates.status: publishe