Influence of design parameters on the performance of a refractive index sensor based on SPR in plastic optical fibers

We report a refractive-index sensor based on surface plasmon resonance in etched plastic optical-fibers. Impact of fiber residual thickness and sensing length on the sensor's sensitivity is experimentally investigated

Synthesis and Preliminary Pharmacological Evaluation of New Analogues of Diclofenac as Potential Anti-inflammatory Agents

A group of amine derivatives [4-aminobenzenesulfonamide derivatives, 2-aminopyridine and 2-aminothiazole] incorporated to α-carbon of diclofenac a well known non-steroidal anti-inflammatory drug (NSAID) to increase bulkiness were designed and synthesized for evaluation as  a potential anti-inflammatory agents with expected COX-2 selectivity. In vivo acute anti-inflammatory activity of the selected final compounds (9, 12 and 13) was evaluated in rats using egg-white induced edema model of inflammation in a dose equivalent to (3 mg/Kg) of diclofenac sodium. All tested compounds  produced a significant reduction  in paw edema with respect to the effect of propylene glycol 50% v/v (control group). Moreover, the 4-aminobenzenesulfonamide derivative (compound 9) exhibited superior anti-inflammatory activity compared to diclofenac sodium at times 180-300 minutes with the same onset of action. The results of this study indicate that the incorporation of the selected aromatic amino groups in to diclofenac maintain its anti-inflammatory activity.                                                                                                                              Key words: amine derivatives, anti-inflammatory, diclofenac derivatives, COX-2 selectivity

Optical Nonlinear Refractive Index of Laser-Ablated Gold Nanoparticles Graphene Oxide Composite

Gold nanoparticles were prepared in graphene oxide using laser ablation technique. The ablation times were varied from 10 to 40 minutes, and the particle size was decreased from 16.55 nm to 5.18 nm in spherical shape. The nanoparticles were capped with carboxyl and the hydroxyl groups were obtained from Fourier transform infrared spectroscopy. Furthermore, the UVvisible peak shifted with decreasing of nanoparticles size, appearing from 528 nm to 510 nm. The Z-scan technique was used to measure the nonlinear refractive indices of graphene oxide with different concentrations and a gold nanoparticle graphene oxide nanocomposite. Consequently, the optical nonlinear refractive indices of graphene oxide and gold nanoparticle graphene oxide nanocomposite were shifted from 1.63 × 10 −9 cm 2 /W to 4.1 × 10 −9 cm 2 /W and from 1.85 × 10 −9 cm 2 /W to 5.8 × 10 −9 cm 2 /W, respectively

Topical piroxicam in vitro release and in vivo anti-inflammatory and analgesic effects from palm oil esters-based nanocream

During recent years, there has been growing interest in use of topical vehicle systems to assist in drug permeation through the skin. Drugs of interest are usually those that are problematic when given orally, such as piroxicam, a highly effective anti-inflammatory, anti-pyretic, and analgesic, but with the adverse effect of causing gastrointestinal ulcers. The present study investigated the in vitro and in vivo pharmacodynamic activity of a newly synthesized palm oil esters (POEs)-based nanocream containing piroxicam for topical delivery

Broadly tunable multiwavelength fiber laser with bismuth-oxide EDF using large effective area fiber

A multiwavelength laser comb using 2.49 m Bismuth-oxide erbium-doped fiber (Bi-EDF) with different lengths of large effective area fiber (LEAF) in a ring cavity configuration is realized. The Bi-EDF is used as the linear gain medium and LEAF is used as the non-linear gain medium for stimulated Brillouin scattering. Out of the four different lengths, the longest length of 25 km LEAF exhibits the widest tuning range of 44 nm (1576 to 1620 nm) in the L-band at 264 mW pump power and 5 mW Brillouin pump power. In addition, a total of 15 output channels are achieved with total average output power of -8 dBm from this laser structure. All Brillouin Stokes signals exhibit high peak power of above -20 dBm per signal and their optical signal-to-noise ratio of greater than 15 dB

Stability Studies of Nano-Scaled Emulsions Containing Ibuprofen for Topical Delivery

Biphasic systems, like emulsions and nano-scaled emulsions, are naturally unstable. The extent and rate of the destabilization process differ from system to another. The stability of such systems upon storage is an important aspect to ensure their abilities to exert the expected effects and consequently render them pharmaceutically acceptable. In the present study, the stability of the nano-scaled emulsion containing newly synthesized palm oil esters (POEs) was assessed under different storage conditions and over specified durations. Three nano-scaled emulsion formulae were chosen for this investigation. They basically comprised ibuprofen as the active ingredient, triethanolamine aqueous solution pH 7.4 as the external phase, POEs as the oil phase, Tween 80 as an emulsifier, Carbopol® 940 as the rheology modifier and menthol or limonene as penetration promoters. The evaluation processes were carried out at several temperatures (4, 25 and 40 °C) with factors, such as droplets size, electrical conductivity, drug content, pH and flow properties were relatively held constant. The data collectively showed that all formulations were stable over an observation period of three months.Keywords: Ibuprofen, nano-scaled emulsion, palm oil esters, stabilit

Modification and Validation of an HPLC Method for Quantification of Piroxicam

Piroxicam is a NSAID that is widely used in the treatment of joint pain and osteoarthritis. The objectives of the study were to modify and validate HPLC method so as to obtain an accurate, sensitive and precise method to quantify piroxicam concentrations without interference from the other ingredients presence in the formulation. The method published by Owen et al. was adapted and modified to suit the above requirements. The modification was carried out on the mobile phase as the mobile phase used by the authors was not able to separate the drug peak from the interference of the formulation excipients. The modified mobile phase consisted of 5 mM of disodium hydrogen phosphate adjusted to pH 3 with concentrated ortho phosphoric acid, methanol, acetonitrile and glacial acetic acid at ratios of 27:20:52:1 respectively. The method was validated and found to be specific, precise, accurate and reproducible even when run at different times of the same day or on different times on different days. The limit of detection and quantification were determined to be 0.035 μg/ml and 0.0625 μg/ml respectively. It could be concluded that this method could be used to determine piroxicam concentration in the samples collected from in vitro study of permeability through the synthetic membrane and excised rat skin.Keywords: Piroxicam, HPLC, Quantification analysis, Modification

Study of Pseudoternary Phase Diagram Behaviour and the Effect of Several Tweens and Spans on Palm Oil Esters Characteristics

Palm oil esters are high molecular weight esters oil that has been newly synthesized by University Putra Malaysia researchers. It has received a lot of attention for its pharmaceutical and chemical application. The aim of this study is to study the effects of the palm oil esters with different HLB surfactant mixture on the ternary diagrams behaviour and to confine the various systems resulted from these combinations. These systems include traditional emulsion, gel area, transpernat micro-emulsion area, O/W and W/O emulsions. In this study, pseudoternary phase diagrams of water, POEs and non-ionic surfactant mixture of several HLB values were constructed using water titration method. The resultant mixtures collected after each addition and mixing of water were analysed visually, along with conductivity, dilution in water and dye test (methylene blue) to classify them as O/W emulsion (transparent and opaque) or W/O (opaque) and liquid or gel. As a conclusion, palm oil esters were found to be suitable for the formulation of different types of emulsion. Additionally, different HLB value of non-ionic surfactant(s) exhibited different pseudoternary phase diagram characteristics.Keywords: palm oil esters, Tween, Span, Pseudoternary phase diagram, O/W emulsio

Study of Pseudoternary Phase Diagram Behaviour and the Effect of Several Tweens and Spans on Palm Oil Esters Characteristics

Palm oil esters are high molecular weight esters oil that has been newly synthesized by University Putra Malaysia researchers. It has received a lot of attention for its pharmaceutical and chemical application. The aim of this study is to study the effects of the palm oil esters with different HLB surfactant mixture on the ternary diagrams behaviour and to confine the various systems resulted from these combinations. These systems include traditional emulsion, gel area, transpernat micro-emulsion area, O/W and W/O emulsions. In this study, pseudoternary phase diagrams of water, POEs and non-ionic surfactant mixture of several HLB values were constructed using water titration method. The resultant mixtures collected after each addition and mixing of water were analysed visually, along with conductivity, dilution in water and dye test (methylene blue) to classify them as O/W emulsion (transparent and opaque) or W/O (opaque) and liquid or gel. As a conclusion, palm oil esters were found to be suitable for the formulation of different types of emulsion. Additionally, different HLB value of non-ionic surfactant(s) exhibited different pseudoternary phase diagram characteristics.Keywords: palm oil esters, Tween, Span, Pseudoternary phase diagram, O/W emulsio

Modification and Validation of an HPLC Method for Quantification of Piroxicam

Piroxicam is a NSAID that is widely used in the treatment of joint pain and osteoarthritis. The objectives of the study were to modify and validate HPLC method so as to obtain an accurate, sensitive and precise method to quantify piroxicam concentrations without interference from the other ingredients presence in the formulation. The method published by Owen et al. was adapted and modified to suit the above requirements. The modification was carried out on the mobile phase as the mobile phase used by the authors was not able to separate the drug peak from the interference of the formulation excipients. The modified mobile phase consisted of 5 mM of disodium hydrogen phosphate adjusted to pH 3 with concentrated ortho phosphoric acid, methanol, acetonitrile and glacial acetic acid at ratios of 27:20:52:1 respectively. The method was validated and found to be specific, precise, accurate and reproducible even when run at different times of the same day or on different times on different days. The limit of detection and quantification were determined to be 0.035 μg/ml and 0.0625 μg/ml respectively. It could be concluded that this method could be used to determine piroxicam concentration in the samples collected from in vitro study of permeability through the synthetic membrane and excised rat skin.Keywords: Piroxicam, HPLC, Quantification analysis, Modification