Journal of Advanced Biomedical Sciences

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Background & Objective: Molecular typing is an important tool in surveillance and outbreak investigations of human Salmonella infections. In this study, Subtyping of Salmonella Paratyphi B and C isolates derived from Iranian patients was carried out by RAPD-PCR to assess the extent of genetic diversity of these isolates.

Materials & Methods: Fourteen Salmonella isolates including 6 strains of Salmonella paratyphi B and 8 strains of Salmonella paratyphi C were characterized using RAPD-PCR. Two arbitrary primers, namely OPP-16 and P1254 were used for RAPD analysis and the dendrograms were constructed with NTsys 2.0 computer software.

Results: Both primers showed high discriminatory power in differentiating of the related strains of Salmonella. The dendrograms constructed based on RAPD-PCR profiles (with both primers) involving 14 salmonella strains revealed 4 distinct patterns, indicating that these isolates are genetically heterogeneous. Furthermore, a good correlation was not observed between the serotype and the molecular profiles obtained from RAPD data of the Salmonella isolates.

Conclusion: The findings of the present study verify the usefulness of RAPD-PCR in characterizing and comparing strains of Salmonella Paratyphi B and C.

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Background & Objective: Solid dispersions (SDs) have been traditionally used as an effective method for improving the dissolution properties and bioavailability of poorly water-soluble drugs. The aim of this study was to improve the solubility and dissolution rate of paracetamol by SD technique.
Materials & methods: The prepared SDs were evaluated by saturation solubility test, In-vitro drug release test, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM).
Results: The prepared SDs exhibited a statistically significant increase in the solubility of paracetamol compared to that of the free drug (p < 0.05). After 15 min SD tablets had an enhanced cumulative drug release compared to tablets of the free drug (p < 0.05). FTIR study revealed that paracetamol was stable in polymeric dispersions. DSC and SEM microscopy showed that the drugs crystallinity was decreased during the preparation process (amorphous crystal formation).
Conclusion: The FTIR spectroscopic test revealed the presence of intermolecular hydrogen bonding between paracetamol and the polymers in the SDs, which could increase the aqueous solubility of the drug. The DSC analysis indicated that the drug was in the amorphous state when dispersed in the polymers. Dissolution studies indicated that the dissolution rates were markedly increased in the SDs compared with those of paracetamol alone, and Better results were obtained with PVP K25.