Spectrophotometric determination of bacitracin in bulk drug as dabsyl derivative in a range of visible light

A fast spectrophotometric method has been developed for bacitracin identification and determination after condensation reaction with dabsyl chloride. In addition, determination of dye stability of sulfonamide derivative and identification of the molar ratio of reagents was done at various time-points. The developed method has a good linearity with very broad spectrum, correlation coefficient of r = 0.9972, good precision (RSD = 1.54 ± 0.11%), and recovery at three different levels of concentration was found between 98.33% and 103.47%. Usefulness of the method was demonstrated by positive results obtained during determination of bacitracin concentration in bulk drug

Photostability of triazole antifungal drugs in the solid state

The publication is devoted to photostability assessment of four triazole antifungal drugs: fluconazole, itraconazole, posaconazole and voriconazole. The compounds were exposed in the solid state using the whole spectrum of UV-Vis radiation. The analyses were performed using high performance thin layer chromatography (HPTLC) technique with densitometric detection. The results indicates considerable degradation of structurally similar itraconazole and posaconazole which could be clinically significant. After 72 hours of itraconazole irradiation there remain less than 25%, and 60% in case of posaconazole. To a lesser extent photodegradation concern two other compounds with a separate chemical structure: fluconazole and voriconazole. After 72 hours of irradiation there left 75% and 82% of these substances, respectively. The strict dependence between compound photostability and its chemical structure was observed

Determination of azole antifungal medicines using zero-order and derivative UV spectrophotometry

This paper presents a new methodology of quantitative determination of seven azole antifungal medicines widely used in therapy. Analyses were performed directly by using zero-order (fluconazole), first derivative (bifonazole, clotrimazole, econazole, itraconazole, miconazole) and second derivative (ketoconazole) UV spectrophotometry. Validation of all methods confirms their proper precision (%RSD = 0.47 - 2.86), recovery (98.7 - 101.4) and linearity (r coefficient over 0,999) in concentrations under investigation. The parameters received enable the developed procedure to be used in quantitative and as auxiliary in qualitative pharmaceutical analysis

Determination of Se(IV), Cd(II) and Pb(II) ions in homeopathic drugs by inversion voltammetry method

The conditions for identification and quantification of Se(IV), Cd(II) and Pb(II) ions in homeopathic drugs by inversion voltammetry method with the use of EAGRAPH software were established. The studies proved that the method was of high sensitivity in established conditions. The detection limits were 0.66 μg/mL, 0.08 μg/mL and 0.12 μg/mL for Se(IV), Pb(II) and Cd(II) ions, respectively. This method was characterized by repeatability of measurements, a wide range of linearity and satisfactory percent recovery

Determination of retinyl palmitate in ointment by HPLC with diode array detection

A simple and rapid HPLC with diode array detection method was developed for the determination of retinyl palmitate present together with other active substances in an ointment. Chromatographic separation was performed on 100 RP-18 Lichrospher column of particle size 5 μm. The mobile phase was methanol:water (98:2, v/v) and flow rate was 2.0 mL/min in isocratic mode. Samples were analyzed for 30 min. Spectophotometric detection was conducted at 325 nm. Under these conditions, the method featured high sensitivity, good precision and comparability of results as proven by the method validation and statistical analysis of the results. The limits of detection and determination were 0.4317 mg/100 mL and 1.3081 mg/100 mL, respectively, recovery values were measured at three levels 80%, 100% and 120% and yielded 101.05%, 101.34% and 100.43%, respectively. The linearity range was checked from 2 mg/100 mL to 10 mg/100 mL. The precision and inter-day precision of the method was expressed by relative standard deviation value and did not exceed 1.68%

Quantification of active pharmaceutical ingredients in commercially available poly pharmaceutical tablets by means of DSC

Differential scanning calorimetry is the first line technique indispensable for industrial quality controllaboratories and, next to many routine applications, could be used in quantitative assays. For this purpose, a relationship between the signal value of analyte (enthalpy change ΔH) and its concentration in the matrix isused. However, there are several limitations of its application, concerning solid state interactions between APIs, other APIs and/or coexisting excipients. With respect to their physical properties, it is known that amorphization state and/or permanent particle deformation can produce relatively large areas of interparticle contact and thus high particle-particle bonding forces. Finally, it may affect the DSC quantitative measurements. The problem was shown using commercially available, different poly component tablets containing ibuprofen in the presence of pseudoephedrine hydrochloride or paracetamol and coexisting excipients