Determination of Sodium Fluoride in Dental Mouth Wash and Oral Multivitamin Formula Using RP-HPLC Precolumn Derivatization Reaction

An accurate, selective and sensitive reversed phase-HPLC method has been developed and validated for selective determination of sodium fluoride in dental mouth wash and oral multivitamin formula. The method was based on a precolumn derivatization reaction of sodium fluoride with triphenyl silyl hydroxide in acidic conditions then the product (triphenyl silyl fluoride) was extracted into n-heptane. Limit of quantification and limit of detection for sodium fluoride were found to be 1.07 and 0.35 µg/ml; respectively. A Zorbax® eclipse HC-C18 column (250 mm x 4.6 mm x 5 μm) was used for separation with acetonitrile: water (75:25, v/v) as the mobile phase (flow rate 0.5 ml/min), temperature was adjusted at 40˚C with detection wavelength of 222nm. The retention time was found to be about 8.6 min. The method exhibited a wide linear range of response from 1-300µg/ml with a correlation coefficient of 0.9998 and percentage recovery of 99.50 ± 0.792. Recoveries in dosage forms were found to be 99.33± 0.818 and 98.76 ± 0.930 for dental mouth wash and oral multivitamin formula; respectively. The developed analytical method has been validated for selectivity, linearity, precision, accuracy, and robustness according to ICH guidelines. The developed method could be successfully employed for routine analysis of fluoride ion in pharmaceutical formulations as well as in a wide range of matrices due to high selectivity of the method

Ecofriendly Long Life Nanocomposite Sensors for Determination of Carbachol in Presence of Choline: Application in Ophthalmic Solutions and Biological Fluids

Several emerging nano scale forms of carbon are showing great promise in electrochemical sensing such as graphene and multi-walled carbon nanotubes (MWCNTs). Herein we present an ecofriendly method to fabricate long life and sensitive ion selective sensors based on graphene and MWCNTs nanocomposites with no need for volatile organic solvents. Both sensors were fabricated, for the analysis of carbachol in ophthalmic solutions, plasma and urine where ion- association complex was formed between cationic carbachol and anionic Sodium tetra phenyl borate (NaTBP) in a ratio 1:1. Both sensors were evaluated according to the IUPAC recommendation data, revealing linear response in the concentration range 10−7 M to 10−2 M with near Nernstian slopes 50.80 ± 5 and 58.14 ± 3 mV/decade and correlation coefficients 0.9992 and 0.9998 for graphene and MWCNTs based sensors, respectively. Both sensors were successfully applied as stability indicating method for the analysis of carbachol in presence of its metabolite choline, in ophthalmic preparations, in plasma and urine showing good recovery percentage values. MWCNTs based sensor showed some advantages over graphene sensor regarding lower limit of detection (LOD), longer life time and higher selectivity towards carbachol. Statistical comparison of the proposed sensors with the official method showed no significant difference for accuracy and precision

Universal procedures for spectrophotometric determination of anticoccidial drugs; application to multi-ingredient veterinary formulation and computational investigations for multivariate analysis

Simple, accurate, and eco-friendly spectrophotometric procedures were proposed and implemented for simultaneous determination of anticoccidial drugs from three different classes namely, amprolium hydrochloride (AMP), sulfaquinoxaline sodium (SQX) and diaveridine hydrochloride (DVD). Dual wavelength in ratio spectra procedure was proposed where the difference in amplitudes (ΔP) in the ratio spectra at 264 nm and 301.9 nm (ΔP264&301.9 nm) corresponded to AMP with mean percentage recovery 100.00±0.923%, while (ΔP250.9&279 nm) and (ΔP218&243.5 nm) corresponded to SQX and DVD with mean percentage recoveries 99.31±1.083 and 100.64±1.219%, respectively. The dual wavelength in ratio spectra procedure was validated according to the ICH guidelines and accuracy, precision and repeatability were found to be within the acceptable limit. Multivariate chemometric approaches, namely, partial least-squares (PLS-2) and principal component regression (PCR) were also proposed with mean percentage recoveries 99.31±0.769, 98.91±1.192 and 99.04±1.245% for AMP, SQX and DVD, respectively, in PLS-2 and 99.63±1.005, 99.11±1.272 and 98.93±1.338% for AMP, SQX and DVD, respectively, in PCR. These procedures were successfully applied to the multi-ingredient veterinary formulation with mean percentage recoveries 100.75±1.238, 99.29±0.875 and 99.34±0.745% for AMP, SQX and DVD, respectively, in dual wavelength in ratio spectra procedure and 101.03±1.261, 101.48±0.984 and 101.10±1.339% for AMP, SQX and DVD, respectively, in PLS-2 and 100.22±1.204, 101.10±0.546 and 100.91±0.677% for AMP, SQX and DVD, respectively, in PCR