COMPARATIVE IN VITRO DISSOLUTION STUDY OF SPIRONOLACTONE FROM BINARY AND TERTIARY SOLID DISPERSION: MODEL DEPENDANT AND INDEPENDENT APPROACHES

 Abstract: In this study solid dispersions (SDs) of spironolactone were prepared by solvent evaporation technique using poloxomer 407,  kollicoat IR, kollidon VA 64 and PEG 6000 as carrier. The solid dispersions were investigated for drug loading and dissolution behavior. Solid dispersions were found effective to enhance the solubility of spironolactone significantly in the dissolution media. Dissolution test was carried out purified water. Solid dispersion containing kollidon VA 64 at the ratio of 1:20, showed faster and higher drug release and was found most effective among all the solid dispersions. Drug carrier interactions were studied by comparing Fourier Transformed Infrared Spectroscopy (FT-IR) spectra of solid dispersions with pure drug and the SDs were found stable. Dissolution results of all the formulations were compared by using difference factor (f1), similarity factor (f2), dissolution efficiency (%DE) and multiple comparison Bonferroni test. No significant difference was found among the binary SDs containing 1:5 carrier, on the other hand all the ternary SDs were also found similar. So, solid dispersion technique may be an effective technique to enhance dissolution rate of spironolactone

Characterization and Compatibility Studies of Different Rate Retardant Polymer Loaded Microspheres by Solvent Evaporation Technique: In Vitro-In Vivo Study of Vildagliptin as a Model Drug

The present study has been performed to microencapsulate the antidiabetic drug of Vildagliptin to get sustained release of drug. The attempt of this study was to formulate and evaluate the Vildagliptin loaded microspheres by emulsion solvent evaporation technique using different polymers like Eudragit RL100, Eudragit RS100, Ethyl cellulose, and Methocel K100M. In vitro dissolution studies were carried out in 0.1 N HCl for 8 hours according to USP paddle method. The maximum and minimum drug release were observed as 92.5% and 68.5% from microspheres, respectively, after 8 hours. Release kinetics were studied in different mathematical release models to find out the linear relationship and release rate of drug. The SEM, DSC, and FTIR studies have been done to confirm good spheres and smooth surface as well as interaction along with drug and polymer. In this experiment, it is difficult to explain the exact mechanism of drug release. But the drug might be released by both diffusion and erosion as the correlation coefficient (R2) best fitted with Korsmeyer model and release exponent (n) was 0.45–0.89. At last it can be concluded that all in vitro and in vivo experiments exhibited promising result to treat type II diabetes mellitus with Vildagliptin microspheres

Studies on Swelling Behavior of HPMC based Matrix Tablets by the Application of Digital Imaging Technique

ABSTRACT: The widespread application of hydrogels in a number of applications like control of microfluidic flow, development of muscle-like actuators, filtration/separation and drug delivery makes it important to properly understand these materials. Understanding hydrogel properties is also important from the standpoint of their similarity to many biological tissues. The degree of swelling as well as the rate of swelling of the hydrogel was studied through experiments using digital photography. First of all the matrix was prepared by blending properly weighed HPMC, Theophylline and excipients in a laboratory mixture for 10 minutes followed by compression with 5 ton force for 30 seconds. The study was designed to evaluate the effect of hydrophobic materials on HPMC matrix tablets in terms of in vitro swelling study. Different viscosity grades of HPMC i.e. 6- cps, 15-cps and 50-cps were used to prepare tablets along with various hydrophobic materials. Among the hydrophobic materials stearic acid (SA), cetyl alcohol (CA), bees wax (BW), glyceryl monostearate (GMS), cetostearyl alcohol (CSA) and stearyl alcohol (STA) were used. It was found that presence of hydrophobic ingredients in the HPMC hydrogel matrix substantially reduces swelling of the matrix. In this work, the extent of swelling of HPMC matrix was evaluated by using digital photography and counting the pixels with Photoshop software. Finally, it was shown from the experiment that the rate and extent of drug release is mainly governed by swelling rate of different HPMC viscosity grade used and the nature of hydrophobic materials included into the matrix system

ENCAPSULATION OF ZIDOVUDINE IN DIFFERENT CELLULOSIC ACRYLIC AND METHACRYLIC POLYMERS LOADED MICROSPHERES: IN VITRO CHARACTERIZATION AND COMPATIBILITY STUDIES

Objective: The attempt of the present study was to improve bioavailability and dissolution rate along with reduction in dosing frequency of Zidovudine from microspheres.Methods: In this study an effort was taken to devise and evaluate Zidovudine sustained release microspheres using different polymers such as Ethyl cellulose (EC), Eudragit RS100, Hydroxypropyl methylcellulose (Methocel K4M and Methocel K15M) by emulsion solvent evaporation method. UV-Spectrophotometric method was applied to calculate the drug content and in vitro dissolution studied according to USP paddle method were carried out in Phosphate Buffer (pH 7.4) for 8 hours. Scanning electron microscopic (SEM) technique was performed to obtain the particle size and morphological changes due to different polymers. Drug polymer compatibility studies were performed by Fourier Transform Infrared (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC) and X-ray Powder Difftactometry (XRD).Results: The maximum and minimum releases of microspheres were observed 93.12% and 75.07% respectively after 8 hours. Drug entrapment efficiency for formulations varied from 56.21% to 94.14%. The release kinetics were studied in different mathematical release models following the zero order, first order, Higuchi, Hixson-Crowel and korsemeyer to find out the linear relationship and release rate of drug. In this experiment, it is difficult to explain the exact mechanism of drug release. The drug might be released by both diffusion and erosion as the correlation coefficient (R2) best fitted with Korsemeyer model. No interaction between drug and polymers were observed from FTIR, DSC and XRD studies.Conclusion: In vitro study and different compatibility evaluation of Zidovudine from microspheres was showed that optimum release profiles may be obtained compared to pure drug