This paper describes preparation and characterization of beads of alginate and psyllium containing probiotic bacteria ofLactobacillus acidophilusDMSZ20079. Twelve different formulations containing alginate (ALG) and alginate-psyllium (ALG-PSL) were prepared using extrusion technique. The prepared beads were characterized in terms of size, morphology and surface properties, encapsulation efficiency, viabilities in acid (pH 1.8, 2 hours) and bile (0.5% w/v, 2 hours) conditions, and release in simulated colon pH conditions. The results showed that spherical beads with narrow size distribution ranging from1.59±0.04to1.67±0.09 mm for ALG and from1.61±0.06to1.80±0.07mm for ALG-PSL with encapsulation efficiency higher than 98% were achieved. Furthermore, addition of PSL into ALG enhanced the integrity of prepared beads in comparison with ALG formulations. The results indicated that incorporation of PSL into alginate beads improved viability of the bacteria in acidic conditions as well as bile conditions. Also, stimulating effect of PSL on the probiotic bacteria was observed through 20-hour incubation in simulated colonic pH solution. According to ourin vitrostudies, PSL can be a suitable polymer candidate for partial substitution with ALG for probiotic coating.

Naproxen was crystallized from acetone-water in the presence of different concentrations of hydroxypropylcellulose (HPC). Naproxen particles recrystallized in the presence of HPC exhibited an obvious improvement in their packing, flow, and mechanical properties compared to naproxen recrystallized in the absence of the polymer (control particles). The results showed that the particle size distributions of the treated samples were broader than those obtained when HPC was absent. The agglomerates produced in the presence of 0.25% HPC displayed superior flow characteristics (displaying both a low angle of repose and Carr index) in comparison to samples produced in the presence of other concentrations of HPC. This was attributed to the spherical shape and smooth surface, since the area of contact in the powder bed for spherical agglomerates was smaller than that for other crystal shapes. However it was found that the tensile strength of tablets with the particles isolated in the presence of 1% HPC was increased to a greater extent than tablets produced using the spherical particles. Generally, the tensile strengths of the tablets increased with increasing concentrations of HPC present in the crystallization medium. Differential scanning calorimetry (DSC) and X-ray powder diffraction studies showed that naproxen particles, crystallized in the presence of HPC did not undergo structural modifications.

Objective: To improve the dissolution rate of piroxicam (PX), enteric-release microparticles having solid dispersion (SD) structure were prepared in one step. Methods: SD of PX and Eudragit S100 (Eu S100) with the aid of silicon dioxide (Aerosil® 200), as an antiadhesion agent, were prepared by spherical crystallization technique. The microparticles were characterized by differential scanning calorimetry, X-ray powder diffraction, and Fourier transform infrared spectroscopy and were evaluated for yield, encapsulation efficiency, flowability, packability, and drug release (at pH 1.2 and pH 7.4). The samples were stored at severe condition [40°C, 75% relative humidity (RH)] for 3 months to investigate their stability. The effects of the polymer–drug and polymer–Aerosil ratios on the characteristics of the microparticles were also investigated. Results: PX microparticles exhibited significantly improved micromeritic properties in comparison to the crystalline pure drug. The dissolution of drug from microparticles in phosphate buffer (pH 7.4) indicated a significant increase in dissolution of PX when dispersed in Eu S100. The results of X-ray powder diffraction and differential scanning calorimetry analysis indicated that in microparticles at 2:1 Eu S100:PX ratio the crystalline form of PX was disordered, suggesting that PX was highly dispersed in microparticles, as that in the amorphous state. Fourier transform infrared spectroscopy analysis demonstrated the presence of intermolecular hydrogen bonding between PX and Eu S100 in SD. In stability test, the release profiles of the microparticles were unchanged as compared with the freshly prepared SDs; amorphous PX in the SD particles did not crystallize under storing at 40°C, 75% RH for 3 months.