Mohd Affendi Mohd Shafri

Spectrophotometric Determination of Gentamicin Loaded PLGA Microparticles and Method Validation via Ninhydrin-Gentamicin Complex as a Rapid Quantification Approach

The purpose of this study was to provide a quantification method with rapid, sensitive, reproducible and cost effective for gentamicin in the form of ninhydrin-gentamicin complex. The utilization of spectrophotometric module to validate the method development for gentamicin loaded microparticles was intended to provide alternative quantification method without compromising the sensitivity of the developed method. The wavelength was determined to be at 418 nm with 421 nm and 415 nm were selected for the robustness of the method selectivity. The linearity of 6 known concentrations of ninhydrin-gentamicin complex was obtained with the R2 of 0.9998. The interday and intraday precisions were determined with the acceptance %RSD values of less than 2%. In fact, the highest %RSD value was 1.09% which suggested the method to be acceptably precise. The LOD and LOQ values were recorded to be at 0.016 mg/mL and 0.196 mg/mL respectively. The % recovery of 4 known concentrations indicated the accuracy of the method was high with the recovery range between 98.66% to 101.8%. The parameters analyzed in this study were in accordance with ICH Q2 (R1) guidelines. This quantification method developed by using spectrophotometric module was a promising approach to provide a rapid and cost effective in evaluating gentamicin concentration for in-vitro applications.

Method Development and Validation using UV Spectrophotometry for Nigella sativa Oil Microparticles Quantification

Nigella sativa oil (NSO) has been exploited for medical purposes for many generations. The fabrication of microparticles containing NSO intended for sustained release was done to be used in treating osteomyelitis. Method in quantifying NSO using UV-spectroscopy was developed and validated. Linearity shown a good correlation coefficient with the values higher than 0.995, both for actual and different analysts. The LOD and LOQ values were recorded to be 2.89 µg/mL and 8.75 µg/mL respectively. In addition, the highest %RSD values for the intermediate and repeatability studies were 0.970% and 0.445% which suggested the method was precise. The percentage recovery for 4 known concentrations gave the range between 98.16% to 99.39%, indicating the high accuracy of the method. The parameters analyzed in this study were in accordance with ICH Q2 (R1) guidelines.

Comparative assessment of plasmid DNA delivery by encapsulation within or adsorbed on poly (D, L-lactide-coglycolide) nanoparticles

Purpose : To compare the gene delivery effectiveness of plasmid DNA (pDNA) encapsulated within poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles with that adsorbed on PLGA nanoparticles. Methods: PLGA nanoparticles were prepared using solvent-evaporation method. To encapsulate pDNA within the particles, it was first complexed with cetyltrimethylammonium bromide (CTAB) and then added to the oil phase during the synthesis. For the adsorption, PLGA nanoparticles were first modified with either CTAB or chitosan and then pDNA was adsorbed on the particle surface by electrostatic interaction. Results : Nanoparticles encapsulating pDNA exhibited better plasmid loading and protection with significantly lower burst release (p < 0.05) compared to that of the nanoparticles with adsorbed plasmid. Cell uptake of chitosan-modified nanoparticles by murine neuroblastoma (N2a) cells was significantly (p < 0.05) higher than that of chitosan-free nanoparticles. Nanoparticles encapsulating pDNA showed higher transfection efficiency (p < 0.05) in N2a cells. Conclusion : Encapsulation of pDNA within PLGA nanoparticles presents a potential strategy for gene delivery that is superior to pDNA adsorbed on the nanoparticle surface. In addition, encapsulation keeps the particle surface free for further modifications such as the addition of targeting ligands. Keywords : Poly (D,L-lactide-co-glycolide), Plasmid DNA, Encapsulation, Adsorption, Cellular uptake, Gene therapy, Targeting ligands

Isolation of the biofilm producing bacteria from osteomyelitis patients at Hospital Tengku Ampuan Afzan (HTAA), Kuantan

Aims: Accurate diagnosis and proper treatments of osteomyelitis are often difficult and ineffective due to several reasons such as less sensitive sample collected and the formation of biofilm following prosthetic use. Thus, our goal of this study is to identify suitable sample for laboratory diagnosis and also microbial species that cause osteomyelitic infection and discriminate between biofilm and non-biofilm producing strains in patients at Hospital Tengku Ampuan Afzan, Kuantan. Methodology and results: Samples of bone, prosthetic material, tissue and swab were collected from patient with suspected osteomyelitis at the hospital. Bacteria were isolated from sample using methods such as homogenization, direct transfer, and sonication. Then, species identification was done by colony characterization, biochemical test and the API identification system. Once species identified, tissue culture plate method was performed to discriminate the biofilm-producing strain from the non-biofilm-producing strain. The total number of 57 samples were collected from 17 cases of suspected osteomyelitis with 34 samples were found positive bacterial growth. Prosthetic samples produced highest positive growth with 81.3%, following by bone samples with 66.7% while swab and tissue samples with 46.2% and 43.8% respectively. We found that 14 from total 16 pathogens identified were biofilm producing-strains. Conclusion, significance, and impact of study: Prosthetic and bone samples produced higher bacterial growth, in contrast to other type of samples. Sonication method improves bacterial detection. Biofilm producing-bacteria were also the most common isolated strains from osteomyelitic infection. These have underscored the need to revise current clinical and laboratory practice as proper identification biofilm bacteria may influences management an outcome.