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  • Author: Sipos Emese x
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Abstract

Objective: The study aimed at obtaining and characterizing levofloxacin-loaded, poly(ε-caprolactone) electrospun nanofiber formulations to be used as antibacterial wound dressings. Methods: Drug-loaded nanofibers were obtained by the electrospinning process and their morphology was determined using scanning electron microscopy. Structural analysis of the prepared nanofibers was carried out using differential scanning calorimetry and dissolution testing was performed in order to determine drug release. Results: Both nanofiberous formulations (containing 20 % and 50 % w/w levofloxacin) showed dimensions in the range of few hundred nanometers. Thermograms indicated that the formulation containing 20% levofloxacin was totally amorphized, showing a rapid release of the active, in 20 minutes. Conclusions: The poly(ε-caprolactone)-based electrospun nanofibers, containing levofloxacin presented suitable characteristics for obtaining potential antibacterial wound dressings.

Abstract

Introduction: Simvastatin is an inhibitor of hydroxy-methyl-glutaryl-coenzyme A reductase, used in the treatment of hypercholesterolemia. To enhance its bioavailability by inclusion complexation, as host molecule randommethyl-β-cyclodextrin had been used. After evaluating the complexes we chose the kneading product in 1:2 molar ratio for incorporation of 10 mg simvastatin tablets. Materials and methods: We prepared homogenous mixtures of the inclusion complex and some excipients. The tablets were prepared by direct compression. The tablets were evaluated in regard to: weight uniformity, thickness, diameter, hardness, friability, disintegration and dissolution profile. Results: Weights are in the range of 196-208 mg, diameter 6.83-6.86 mm, height 3.86-4.01 mm, hardness 78.3-113.1 N, friability 0.75- 1.19 %, disintegration above 15 minutes. The dissolved amounts of simvastatin from the tablets are higher compared to the dissolution of pure simvastatin, but lower than the dissolution of the complex itself. Excipients, like disintegrants and lubricants greatly influence the dissolution properties of the tablets. Conclusions: According to our results, tablets containing inclusion complex of simvastatin exhibit better solubility, according to the dissolved amount of simvastatin, than pure drug alone. Proper physical parameters of the tablets are obtained by application of 5 % Primellose

Abstract

To evaluate the influence of different variables on tablet formulations containing enalapril maleate and indapamide as active substances, two separate experimental designs were employed: one for evaluating powder properties and the other for tablet characteristics. Because of the low active pharmaceutical ingredient content, it was hypothesized that both powder and tablet properties could be determined only by the characteristics of excipients. In order to test this assumption, both experimental designs were done with placebo mixtures. The optimized formulation was then evaluated both with and without APIs. Results indicated that filler and lubricant percentage, along with compression force, were the most important variables during the formulation study. The optimized formulation showed similar characteristics in both cases for all responses, except for angle of repose and friability where only minor differences were observed. The combination of the applied approaches (using placebo composition and fractional experimental design) proved to be efficient, cost effective and time saving.

Abstract

Chloramphenicol eye drops are commonly prescribed in concentrations of 0.5-1% in the treatment of infectious conjunctivitis. In terms of ophthalmic solution preparation, the major disadvantage of chloramphenicol consists in its low solubility in water. The solubility is increased by substances that form chloramphenicol-complexes, for example: boric acid/borax or cyclodextrins. Objective: Experimental studies aimed to evaluate the potential advantages of enhancing the solubility and stability of chloramphenicol (API) by molecular encapsulation in b-cyclodextrin (CD), in formulation of ophthalmic solutions buffered with boric acid/borax system. Methods and Results: We prepared four APIb- CD complexes, using two methods (kneading and co-precipitation) and two molar ratio of API/b-cyclodextrin (1:1 and 1:2). The formation of complexes was proved by differential scanning calorimetry (DSC) and the in vitro dissolution tests. Using these compounds, we prepared eight ophthalmic solutions, formulated in two variants of chloramphenicol concentrations (0.4% and 0.5%). Each solution was analyzed, by the official methods, at preparation and periodically during three months of storing in different temperature conditions (4°C, 20°C and 30°C). Conclusions: Inclusion of chloramphenicol in b-cyclodextrin only partially solves the difficulties due to the low solubility of chloramphenicol. The protection of chloramphenicol molecules is not completely ensured when the ophthalmic solutions are buffered with the boric acid/borax system.

Abstract

The aim of this experimental work was the enhancement of water solubility of the lipid lowering atorvastatin, by embedding it in polymer based micro sized fibers obtained by electrospinning. We prepared a polyvinylpyrrolidone (Kollidon 90F®) dispersion and added the active substance. By setting the experimental parameters we obtained four different microfibers containing atorvastatin, and one without the drug. The pH, viscosity and conductivity of the dispersions have been measured. The drug content and dissolution of atorvastatin had been studied by capillary electrophoresis. The size and thermal behavior of the fibers was determined. The parameters of the microfibers are influenced by the experimental parameters of electrospinning. The micro-method for dissolution showed a twofold solubility enhancement.

Abstract

Pediatric, ibuprofen containing orodispersible tablets (ODTs) were prepared using the SeDeM expert system methodology. In order to facilitate formulation, directly compressible ibuprofen was employed (Ibuprofen DC 8TM) and characterized using its SeDeM profile. The mannitol based superdisintegrant Ludiflash® was characterized by the SeDeM-ODT expert system, which also allowed calculation of the optimal excipient concentration in order to obtain suitable tablet hardness and disintegration time. After adding a sweetener and a standard combination of lubricants, the optimized formulation was directly compressed into tablets and evaluated in terms of tablet hardness, friability, disintegration time and dissolution profile. The SeDeM method was applied to determine the amount of corrective excipient (Ludiflash®) required for the compression of Ibuprofen DC 85TM in order to achieve suitable ODTs. Adequate tablet hardness, disintegration time, friability and dissolution profiles were found during tablet evaluation.