Spectrophotometric Determination of Amodiaquine in Bulk and in Pharmaceutical Formulation

ABSTRACT A simple, rapid, accurate and economical spectrophotometric method has been developed for estimation of amodiaquine from bulk and pharmaceutical formulation. The λ max of amodiaquine in methanol and water was found to be 348 nm. The same spectrum was derivatised in to first order derivative; showed maximum amplitude of the trough at 348 nm. The drug follows linearity in the concentration range 2-12 µg/ml with correlation coefficient value 0.998. The proposed method was applied to pharmaceutical formulation and % amount of drug estimated 99.19 % % was found in good agreement with the label claim. The accuracy of the method was checked by recovery experiment performed at three different levels i.e., 80%, 100% and 120 %. The % recovery was found to be in the range 98.54%-99.98%. The low values of % R.S.D. are indicative of the accuracy and reproducibility of the method. The precision of the method was studied as an intra-day, inter-day variations and repeatability. The % R.S.D. value less than 2 indicate that the method is precise. Ruggedness of the proposed method was studied with the help of two analysts. The above method was a rapid and cost-effective quality-control tool for routine analysis of amodiaquine in bulk and in pharmaceutical dosage form

China's Corporate Bond Market Development

A review of recent developments in the Chinese bond market shows that China's private debt market, an important source of financing to foster economic growth, remains relatively small despite recent reforms. Investors at an information disadvantage demand a risk premium to lend money (i.e., buy bonds) and may ultimately refuse to do so (i.e., ration credit). Possible regulatory reforms to mitigate this information lacuna include suitable bankruptcy and insolvency rules, securities laws, rules governing credit-rating agencies, and market measures (e.g., appropriately regulated credit-derivative market and/or event-risk provisions in bond indentures).

Solid-vapor interactions: Influence of environmental conditions on the dehydration of carbamazepine dihydrate

The goal of this research was a phenomenological study of the effect of environmental factors on the dehydration behavior of carbamazepine dihydrate. Dehydration experiments were performed in an automated vapor sorption apparatus under a variety of conditions, and weight loss was monitored as a function of time. In addition to lattice water, carbamazepine dihydrate contained a significant amount of physically bound water. Based on the kinetics of water loss, it was possible to differentiate between the removal of physically bound water and the lattice water. The activation energy for the 2 processes was 44 and 88 kJ/mol, respectively. As expected, the dehydration rate of carbamazepine dihydrate decreased with an increase in water vapor pressure. While dehydration at 0% relative humidity (RH) resulted in an amorphous anhydrate, the crystallinity of the anhydrate increased as a function of the RH of dehydration. A method was developed for in situ crystallinity determination of the anhydrate formed. Dehydration in the presence of the ethanol vapor was a 2-step process, and the fraction dehydrated at each step was a function of the ethanol vapor pressure. We hypothesize the formation of an intermediate lower hydrate phase with unknown water stoichiometry. An increase in the ethanol vapor pressure first led to a decrease in the dehydration rate followed by an increase. In summary, the dehydration behavior of carbamazepine dihydrate was evaluated at different vapor pressures of water and ethanol. Using the water sorption apparatus, it was possible to (1) differentiate between the removal of physically bound and lattice water, and (2) develop a method for quantifying, in situ, the crystallinity of the product (anhydrate) phase