ABSTRACT
Dissolution behaviour of a poorly water-soluble drug, tadalafil, from its solid dispersion systems with poloxamer 407 has been investigated. Solid dispersion systems of tadalafil were prepared with poloxamer 407 in 1:0.5, 1:1.5 and 1:2.5 ratios using the melting method. Characterization of binary systems with FTIR and XRPD studies demonstrated the presence of strong hydrogen bonding interactions, a significant decrease in crystallinity and the possibility of existence of amorphous entities of the drug. In the binary systems tested, 1:0.5 proportion of tadalafil/poloxamer 407 showed rapid dissolution of tadalafil (DE(30) 70.9 + or - 3.6 %). In contrast, higher proportions of poloxamer 407 (1:1.5 and 1:2.5) offered no advantage towards dissolution enhancement of the drug, indicating altered rheological characteristics of the polymer at its higher concentration, which might have retarded the release rate of tadalafil.
Subject(s)
Carbolines/chemistry , Poloxamer/chemistry , Crystallization , Hydrogen Bonding , Pharmaceutical Vehicles/chemistry , Solubility , TadalafilABSTRACT
Solid dispersion systems of a poorly water-soluble drug, etoricoxib were prepared with poloxamer 188 in 1:0.5, 1:1.5 and 1:2.5 ratios and evaluated by FTIR, powder XRD and dissolution studies. Physical studies demonstrated a strong hydrogen bonding with significant decrease in the crystallinity and formation of amorphous etoricoxib in its binary systems. All binary systems of etoricoxib showed faster dissolution than pure drug alone (P < 0.001). However, 1:2.5 proportion of etoricoxib: poloxamer 188 showed superior performance (DE45: 71.27% +/- 3.85) in enhancing solubility and dissolution rate of etoricoxib suggesting optimum ratio of the carrier.
Subject(s)
Cyclooxygenase 2 Inhibitors/chemistry , Poloxamer/chemistry , Pyridines/chemistry , Sulfones/chemistry , Chemistry, Pharmaceutical/methods , Crystallization , Drug Carriers/chemistry , Etoricoxib , Hydrogen Bonding , Solubility , Spectroscopy, Fourier Transform Infrared , X-Ray DiffractionABSTRACT
The effect of polyvinyl pyrrolidone (PVP) K30 and/or L-arginine on etoricoxib-HPbetaCD complex was investigated. The phase solubility profiles were classified as A(L)-type, both in absence or presence of auxiliary substances used. The apparent stability constant (K(c)) of binary complex obtained at room temperature, 371.80 +/- 2.61 M(-1), was decreased with the addition of PVP and arginine indicating no benefit of addition of auxiliary substances to promote higher complexation efficiency. Therefore, solid etoricoxib-HPbetaCD binary systems were prepared and characterized by proton nuclear magnetic resonance spectroscopy (1HNMR), X-ray powder diffractometry, Fourier transformation-infrared spectroscopy, and dissolution studies. Among all binary systems, a lyophilized product showed superior performance in enhancing dissolution of etoricoxib.
Subject(s)
Cyclooxygenase Inhibitors/chemistry , Excipients/chemistry , Pyridines/chemistry , Sulfones/chemistry , beta-Cyclodextrins/chemistry , 2-Hydroxypropyl-beta-cyclodextrin , Arginine/chemistry , Drug Stability , Etoricoxib , Freeze Drying , Magnetic Resonance Spectroscopy , Povidone/chemistry , Solubility , Spectroscopy, Fourier Transform Infrared , X-Ray DiffractionABSTRACT
A simple, sensitive, rapid, accurate and precise spectrophotometric method has been developed for the estimation of bicalutamide in bulk and pharmaceutical dosage forms. Bicalutamide shows maximum absorbance at 272 nm with molar absorptivity of 2.3399×10(4) l/mol/cm. Beer's law was obeyed in the concentration range of 1.5-18 µg/ml. The limit of detection and limit of quantification were found to be 0.1 and 0.4 µg/ml, respectively. Results of analysis were validated statistically and by recovery studies.
