ABSTRACT
BACKGROUND:As a good candidate for bioresorbable bone graft, carbonate apatite monolith can be prepared by sintering procedure;however, sintering can cause carbonate loss and result in a much lower rate of biodegradation compared to the human bone, thereby influencing the formation of new bone. OBJECTIVE:To fabricate low-crystal inity carbonate apatite monolith as bone graft and test its properties. METHODS:Calcium carbonate monolith prepared by carbonation of Ca(OH) 2 monolith was treated in 1 mol/L RESULTS AND CONCLUSION:The calcium carbonate completely transformed into low-crystal inity B-type carbonate apatite after treated for 14 days. Diametral tensile strength of the final product was (10.27±1.08) MPa, which is adequate as a reconstruction material for bone defect. The carbonate content was (4.80±0.50)%, similar to that of the nature bone. The molar Ca/P was 1.63±0.01, indicating the Ca-deficient carbonate apatite is obtained. The present method al ows an easy fabrication of low-crystal inity B-type carbonate apatite block with adequate strength and without sintering process. ammonium dihydrogen phosphate solution at 60 ℃ up to 14 days. Diametral tensile strength was examined for biomechanical properties;X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscope observation and chemical analyses (carbonate, calcium and phosphate content) were also performed for physical and chemical properties.
ABSTRACT
A simple, specific, rapid, precise and robust HPLC method has been developed for the quantitation of valsartan in tablet dosage form on a C18 column (250 x 4.6 mm) using a mobile phase consisting of ammonium dihydrogen phosphate buffer : methanol (33.5:66.5) adjusted to pH 3 with formic acid at a flow rate of 1.0 ml/min and detection at 265 nm. The retention time of valsartan was found to be at 11.9 min. The validation of above method was also done. Percentage label claim of the tablet formulations were found to be 100.8%. So the proposed method provides a faster and cost effective quality control tool for routine analysis of valsartan from formulations.