Preparation of Sustained Release Formulation of Verapamil Hydrochloride Using Ion Exchange Resins.

The purpose of this investigation was to formulate and evaluate the interaction between cation exchange resins and verapamil hydrochloride. The uptake studies were conducted using the rotating bottle apparatus. The Langmuir-like equation was applied to the experimental data and the maximum drug loading was determined from the Langmuir-like parameters. The drug-resin complexes were evaluated using XRD, SEM, and particle size analysis. Release studies were performed using USP dissolution apparatus 2. The resin with the lowest percentage of cross-linking had the highest uptake capacity. The percent increase in particle size due to complexation was found to be associated with drug loading; the highest drug loading had the highest increase in particle size. The X-ray diffraction patterns of the resins and the drug-resin complexes showed that they were both amorphous. The maximum drug release was approximately 40% when conventional dissolution testing was used. Results showed that sink conditions could not be maintained using conventional dissolution methods. Maximum drug release increased dramatically by increasing the volume of samples withdrawn and fresh dissolution medium added. Excellent correlation was obtained between sample volume and drug release rate with an R-value of 0.988. Particle diffusion-controlled model and film diffusion-controlled model were both applied to the experimental data. The results indicated that the rate-limiting step is the diffusion of the exchanging cations through the liquid film. The modified release formulation was prepared successfully and correlated very well with the USP monograph for verapamil hydrochloride extended release capsules.

CO2 Supercritical Extraction of Essential Oil of Jordanian Rosemary.

Background: Experimental investigation of supercritical fluid extraction (SFE) of active ingredients from rosemary herb has been performed. Carbon dioxide (CO2) was used as a solvent with ethanol as a trapping agent. This work showed that the SFE can be an exceptional alternative to the use of chemical solvents. Objective: The effect of temperature and pressure on the extraction process was investigated to increase the yield of the extracted essential components. Methods: The types of extracted compounds from rosemary were specified and analyzed using GC-MS. Results: The results indicated that several essential active ingredient compounds were extracted. Furthermore, the pressure affects the extraction, as the composition of some compounds increases with a pressure increase. Conclusions: SFE can be used to extract valuable active ingredients from rosemary. Two process parameters were investigated, namely, pressure and temperature, which indicate that SFE is a selective process for the production of certain constituents. Highlights: Some of the main components of the essential oil of Jordanian rosemary obtained in this study have important applications in pharmaceutical and cosmetic products. For instance, α-pinene is one of the main raw compounds used in the perfume industry.

Removal of 4-Chlorophenol from Contaminated Water Using Activated Carbon from Dried Date Pits: Equilibrium, Kinetics, and Thermodynamics Analyses.

Five different activated carbons (ACs) have been prepared from dried date pits using air and phosphoric acid as activating agents. The used phosphoric acid:date pit ratio dictated the characteristics of the prepared ACs; the equivalent BET-nitrogen surface area varied from 794 m²/g for a ratio of 5:1, to 1707 m²/g for a ratio of 2:1, whereas the micropore volume changed in value from 0.24 cm³/g for the 5:1 ratio to 0.59 cm³/g for the 2:1 ratio. The prepared ACs were tested to remove 4-chlorophenol (4-CP) from aqueous solutions by means of batch adsorption process. The prepared 2:1 AC exhibited the highest uptake with a maximum of 525 mg/g. Equilibrium pH studies showed that 4-CP removal was pH dependent; the maximum uptake occurred at an equilibrium pH value of 5.5. Dynamic studies showed that 4-CP uptake on 2:1 AC is rapid, with 80% of the maximum uptake achieved during the first 40 min. Both surface adsorption and intraparticle diffusion were identified to be effective adsorption mechanisms. Kinetic studies indicated a pseudo second-order reaction. Results of equilibrium adsorption experiments showed that the adsorption of the 4-CP on 2:1 AC is best described by the Langmuir model. The thermodynamics parameters of the adsorption (ΔG°, ΔH°, and ΔS°) were determined by studying the adsorption equilibrium at different temperatures. The values of these parameters indicated the spontaneous and endothermic nature of the adsorption phenomenon of 4-CP on the prepared ACs.