Solubility and dissolution rate of three antiretroviral drugs such as lamivudine, zidovudine and stavudine was studied in four media having different pH. The samples were analyzed by usingUVVisible spectrophotometer. lamivudine shows more solubility that is 276.08 mg/mL in 0.01 N HCl. Stavudine showing highest solubility that is 101.23 mg/mL in pH 4.5 acetate buffer. Zidovudine showing highest solubility that is 28.90 mg/mL in both water and 0.01 N HCl. All three drugs showing lower solubility in pH 6.8 phosphate buffer. Lamivudine and stavudine showing good dissolution rate in all media and showing similar release profiles and good correlation, whereas in zidovudine it was clearly observed a slower release at initial time points and then faster release profiles. The solubility and dissolution data in various media is helpful in predicting the bioavailability and also in dissolution method development.
Purpose: The objective of the present study was to prepare and evaluate microcapsules for the controlled release of lamivudine using various cellulose polymers Methods: The microcapsules were prepared by the solvent evaporation method. The prepared microcapsules were characterized for the percent drug content, entrapment efficiency, FTIR, DSC, scanning electron microscopy (SEM) and in vitro dissolution studies. Accelerated stability studies were also carried out. Results: The microcapsules were spherical and free flowing. The entrapment efficiency was 76-86%. The release of drug from the microcapsules extended up to 8 to 12 hours. FTIR and DSC thermograms showed the stable character of lamivudine in the microcapsules. SEM revealed that the microcapsules were porous in nature. The release kinetics study revealed that the prepared microcapsules were best fitted to the zero order for F-2, F-4 and F-5 formulations and Higuchi model, for F-1 and F-3 microcepsules Conclusion: The release kinetics data and characteristion studies indicate that drug release from microcapsules was diffusion-controlled and that the micrapsules were stable..
New simple, sensitive, rapid, reproducible and economical spectrophotometric method have been developed for the determination of amoxicillin trihydrate in pharmaceutical bulk and tablet dosage form using citro phosphate buffer pH 7.2. The system obeys Lambert-Beer's law at 231 nm in the concentration range 2.5-50 μg/m. Molar absorptivity, correlation coefficient and Sandell's sensitivity values were found to be 1.0020 x 104mol-1cm,-10.9996 and 0.03906 μg cm-2respectively. The proposed methods have been successfully applied to the analysis of the bulk drug and its tablet dosage form. The methods have been statistically evaluated and were found to be precise and accurate
For the development of any formulation, techniques such as thermal and isothermal stress testing were used to assess the compatibility of drug with excepients. Differential scanning calorimetry (DSC) and FTIR were the common methods for the study of compatibility. Isothermal stress testing (IST) is also a method for the compatibility study during proto type formulation. In the present study drug excepient compatibility study of lamivudine was conducted with different controlled release polymers. The drug and polymer mixtures were stored at 50 °C for 2 weeks. The samples were then characterized using DSC, FTIR and UV spectrophotometric methods. The results show that lamivudine was compatible with the all the polymers used in the study. The polymers used in the present study were definitely incorporated in the extended release lamivudine formulation.
A simple, Accurate, precise method was developed for the simultaneous estimation of the Darunavir and Ritonavir in Tablet dosage form. The chromatogram was run through Agilent C18 150 x 4.6 mm, 5m. Mobile phase containing Buffer 0.1% Formic acid: Acetonitrile, taken in the ratio 70:30 was pumped through the column at a flow rate of 0.95 ml/min. The temperature was maintained at 30°C. The optimized wavelength selected was 293 nm. The retention times of Darunavir and Ritonavir were found to be 2.369min and 2.911. %RSD of the Darunavir and Ritonavir were and found to be 0.7 and 0.5 respectively. %Recovery was obtained as 99.67% and 99.78% for Darunavir and Ritonavir respectively. LOD, LOQ values obtained from regression equations of Darunavir and Ritonavir were 1.49, 5.191and 0.37, 1.11 respectively. Regression equation of Darunavir is y = 5421x + 640.7, and y = 3870.x + 5191 of Ritonavir. Retention times were decreased and run time was decreased, so the method developed was simple and economical that can be adopted in regular Quality control tests in Industries.
Discovery of new polymeric materials suitable for prolonging the drug release, and the improvement in therapeutic efficiency and safety achieved by these delivery systems. Now-a-days the technology of controlled release is also being applied to veterinary products. The aim and objective of our current research is to formulate floating and bio adhesive formulations of ciprofloxacin for its controlled delivery to the duodenum which is its best absorption site, thus the oral bioavailability of ciprofloxacin could be improved by using direct compression technique. The experimental results was revealed that the all formulated tablets were of good quality with regard to hardness (3.7-4 kg/cm2), thickness (0.3-0.35 cm), density (~ 1 g/cm3), weight variation (1.3-4.2) and drug content (> 90%). As the result of floating capability study increasing the effervescent base of tablets from 5% to 10% significantly lower the lag time of floating (From about 6 min to 1.5 min) as well as floating duration (From about 21 hrs to 10 hrs). Invitro drug release showed (Fig. 1) that all formulation released 80% of the ciprofloxacin hydrochloride in 12 hrs study period. It was found that all the formulations were statistically significant (p ≤ 0.05).
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