Development and characterization of ethylcellulose based microsphere for sustained release of nifedipine$ / 药物分析学报

This article introduced the work of ethylcellulose based polymeric microsphere loaded with nifedipine for reduction in frequency of administration with low solubility in aqueous medium and high rate of absorption in the stomach. The non-aqueous polymeric suspension was put dropwise into an aqueous medium containing polyvinyl alcohol as a surfactant for the synthesis of microsphere by solvent eva-poration. The microspheres were characterized by different techniques, namely, XRD, SEM, and NMR. The formation of microspheres was confirmed by SEM. XRD analysis revealed the semi-crystallinity nature of microspheres. The NMR study indicated the presence of hetero-aromatic nucleus in the microsphere.

Comparative in vitro antibacterial activities study of some mucoadhesive polymeric suspensions containing fluoroquinolones.

To study in vitro antibacterial activities of mucoadhesive suspensions containing Norfloxacin, Ciprofloxacin and Ofloxacin, three different formulations of each drug were prepared by using three polymers, such as Hydroxypropyl methylcellulose (HPMC), Carbapol934 (C934) and Carbapol940 (C940), along with some common ingredients (bases). For the antibacterial activities study of the samples, agar well diffusion method was performed taking Staphylococcus aureus (ATCC 25923), Bacillus subtilis and Escherichia coli (ATCC 25922). Considering the overall antibacterial activities, it could be mentioned that HPMC containing formulations were superior to others in most of the cases. Amongst C934 and C940 containing suspensions, the former was more potent than the later. Antibacterial activities of most of the formulations were either more effective or similar to those of corresponding drugs in water against the strains used in the study. Only few formulations were inferior to the corresponding drugs in water. Ciprofloxacin in citrate buffer was not better than Ciprofloxacin containing suspensions. Samples like both marketed suspensions and discs of different drugs were inferior to all the formulations and corresponding drugs in water/Ciprofloxacin in citrate buffer. The negative controls of the study, i.e., the different bases, distilled water and citrate buffer did not show any antibacterial activity.