Fabrication and Characterization of Chitosan-Polyethylene Glycol (Ch-Peg) Based Hydrogels and Evaluation of Their Potency in Rat Skin Wound Model

Thermal burns are a major cause of death and suffering around the globe. They can cause debilitating, life-altering injuries as well as lead to significant psychological and financial consequences. Several research works have been conducted in attempt to find a wound healing therapy that is successful. At present, hydrogels have been widely used in cutting-edge research for this purpose because they have suitable properties. This study aimed to see how therapy with chitosan-polyethylene glycol (Ch-Peg) based hydrogels affected the healing of burn wounds in rats. With the concern of public health, xanthan gum (X), boric acid (B), gelatin (Ge), polyethylene glycol (Peg), chitosan (Ch), glutaraldehyde (G), and HPLC-grade water were prepared using X : Ge : G, X : Ge : Peg : G, X : Ge : Ch : G, X : Ge : Peg : Ch : G, X : Ge : B : Ch : G, X : Ge : B : Peg : G, and X : Ge : B : Peg : Ch : G. The produced composite hydrogels were examined for swelling ability, biodegradability, rheological characteristics, and porosity. The 3D structure of the hydrogel was revealed by scanning electron microscopy (SEM). After that, the structural characterization technique named Fourier-transform infrared spectroscopy (FTIR) was used to describe the composites (SEM). Lastly, in a rat skin wound model, the efficacy of the produced hydrogels was studied. Swelling ability, biodegradability, rheological properties, and porosity were all demonstrated in composite hydrogels that contained over 90% water. Hydrogels with good polymeric networks and porosity were observed using SEM. The existence of bound water and free, intra- and intermolecule hydrogen-linked OH and NH in the hydrogels was confirmed using FTIR. In a secondary burned rat model, all hydrogels showed significant wound healing effectiveness when compared to controls. When compared to other composite hydrogels, wounds treated with X : Ge : Peg : Ch : G, X : Ge : B : Peg : G, and X : Ge : B : Peg : Ch:G recovered faster after 28 days. In conclusion, this research suggests that X : Ge : Peg : Ch : G, X : Ge : B : Peg : G, and X : Ge : B : Peg : Ch : G could be used to treat skin injuries in the clinic.

New Validated RP-HPLC Method for Cisplatin and Topotecan in API and Vaccine Form and its Stress Studies

We have developed a completely unique and reliable HPLC technique for simultaneous quantification of Cisplatin and Topotecan. A chromatographic detachment was attained on a XDB C18 column (150x4.6mm, 3.5 µ) using isocratic elution with a buffer containing buffer and acetonitrile with the proportion of 60:40 as a movable phase with a flow of 1 mL/min at room temperature and UV detection was carried out at 262 nm. Dissolve 1mL of triethylamine in 1 lt of HPLC grade water and filter through 0.45 µ filter paper. This solution was used as a buffer. 10 min run time was used to separate Cisplatin and Topotecan. The analysis was achieved within 15 min over honest linearity within the concentration range from 5-75 µg/mL of Cisplatin and 2-30 µg/mL of Topotecan. By injecting the standard six times, system suitability parameters were studied and the outcomes were under the acceptable limit. Precision and recovery study results were found to be within a suitable limit. By using the above technique, the assay of the marketed formulation was performed and found to be within the limit. Degradation studies were carried out on Cisplatin and Topotecan, with a purity threshold greater than the purity angle in all conditions and within the acceptable range. The above-mentioned technique was validated according to ICH guidelines.

Stability Indicative and Cost Effective Creation and Validation of Analytical Method of Lopinavir and Rilpivirine by High Performance Liquid Chromatography

We have developed a completely unique and reliable HPLC technique for simultaneous quantification of Lopinavir and Rilpivirine. Chromatographic detachment was attained on a X-bridge phenyl column (150x4.6mm, 3.5 µ) using isocratic elution with a buffer containing buffer and acetonitrile with the proportion of 70:30 as movable phase with a flow of 1 ml/min at room temperature and UV detection was carried out at 250 nm. Dissolve 1ml of tri ethylamine in 1 lt of HPLC grade water and filter through 0.45 µ filter paper, this solution was used as buffer. 8 min. run time was used to separate Lopinavir and Rilpivirine. Analysis was achieved within 15 min over an honest linearity within the concentration range from 20-300 µg/ml of Lopinavir and 2.5-37.5 µg/ml of Rilpivirine. By injecting the standard six times, system suitability parameters were studied and the outcomes were under the acceptable limit. Precision and recovery study results were found to be within the suitable limit. By using the above technique, assay of Lopinavir and Rilpivirine was performed and found to be within the limit. Degradation studies were carried out on Lopinavir and Rilpivirine, with a purity threshold greater than purity angle in all conditions and within the allowable range. The above mentioned technique was validated according to ICH guidelines.

DEVELOPMENT AND VALIDATION OF NEW STABILITY INDICATING RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF ELBASVIR AND GRAZOPREVIR IN BULK AND PHARMACEUTICAL DOSAGE FORM

The present study describes the development and validation of a new stability indicating RP-HPLC method for simultaneous estimation of elbasvir and grazoprevir in bulk and pharmaceutical dosage form. The chromatographic separation was done by using reverse phase YMC column (4.6 x 250mm, 5μm).The mobile phase used was mixture of HPLC grade water acetonitrile (70:30V/V) at flow rate of 1ml/ min in isocratic mode and detection was carried out using PDA detector at 244nm.The developed method showed a good linearity in the range of 100-500μg/mL for elbasvir and 200-1000 μg/mL for grazoprevir with regression co-efficient of 0.999 for both the drugs. The % recovery of drugs was found to be 100.1% for elbasvir and 100.38% for grazoprevir. The proposed stability indicating method was accurate, precise, robust, stable and specific. The developed method was validated in accordance with ICH guidelines.

HPLC-UV Quantitative Analysis of Acrylamide in Snack Foods of India

An investigation was carried out to determine acrylamide content in 51 popular snacks food of India by using High Pressure Liquid Chromatography (HPLC) Instrument with UV detection method. The method entails acetone extraction of acrylamide, clean up by solid extraction cartridges, isocratic elution with mobile phase of HPLC grade water, acetonitrile and formic acid followed by detection at 210 nm. The limit of detection and the limit of quantification for this method were 5.12 and 17.08 μg/kg, respectively. The mean recoveries of acrylamide obtained by using spiked samples ranged from 91 per cent to 101.33 per cent. Acrylamide concentrations in the five groups of snacks ranged from 788.99 - 4191.82 μg/ for extruded and deep fat fried snack, 372 to 6391μg/ kg for deep fat fried food, 435-3147μg/kg for baked food, 434-1307 μg/kg for breakfast cereal and 471-1520 μg/kg for other snacks. Among the food products, snack foods purchased from unorganised sector showed highest concentration of acrylamide.

Development of validated method for the determination of exemestane by using RP-HPLC

A novel RP-HPLC validated method for determination of Exemestane is developed. The chromatographic separation was done on Phenomenex Luna reversed phase C18 (150 mm x 4.6 mm, 5 μm) column in isocratic mode, using Acetonitrile: HPLC grade water (50:50, v/v) as mobile phase at 254 nm wavelength. Exemestane chromatographic peak is eluted with retention time 4.656 min. The linearity range was 5-30 μg/ml with correlation coefficient 0.999. The method was validated as per ICH Guidelines. The quantification and detection limit for estimation of Exemestane was found to be 0.365 and 1.926 μg/ml respectively. Recovery of Exemestane was found in the range of 98.0-102.0%. Keywords: RP-HPLC; Exemestane; Validation; Estimation

Development and Validation of an HPLC Method for Determination of Thiamethoxam and Its Metabolites in Cotton Leaves and Soil

An easy and simple analytical method was standardized and validated for the estimation of residues of thiamethoxam and its metabolites in cotton. The samples were extracted with acetonitrile, water, and methanol; diluted with brine solution;partitioned into dichloromethane and ethyl acetate; dried over anhydrous sodium sulfate; and cleaned up by glass column chromatography. Final clear extracts were concentrated under vacuum and reconstituted into HPLC grade acetonitrile, and residues were estimated using an HPLC instrument equipped with a C18 column and photodiode array detector system. Acetonitrile–1% formic acid in HPLC grade water (30 + 70) was used as mobile phase at 0.2 mL/min. Consistent recoveries ranging from 82 to 97% for thiamethoxam and its metabolites were observed when samples were spiked at 0.05–1.0 mg/kg levels. The LOQ of the method was determined to be 0.05mg/kg. The analytical method was validated in terms of the selectivity, linearity, precision, and accuracy of the detection system.

Study of Preservatives and Stimulants in Commercial Soft Drinks

Commercially available soft drinks i.e., Sprite and 7up (lemon) samples of 10 different batches were studied by UV-Vis spectrophotometry to find out the presence of preservative and stimulant. The wavelength of absorption maxima (?max) was 224 nm for sodium benzoate and 272 nm for caffeine. The soft drink samples were degassed, extracted with HPLC grade water and cleaned up to study sodium benzoate and caffeine content. The average quantity of caffeine was in the range of 22 to 30 ?g/ml in Sprite and 20 to 30 ?g/ml in 7up (lemon), whereas the average quantity of sodium benzoate was in the range of 181 to 191 ?g/ml in Sprite and 140 to 160 ?g/ml in 7up (lemon) samples. The correlation coefficients of the calibration curves of sodium benzoate and caffeine were found to be 0.9972 and 0.9862, respectively. Recovery experiment was done by spiking sodium benzoate at 20 ?g/ml level with 10 replicate studies. The mean recovery of sodium benzoate was 89.14 ± 2.14 %. The reproducibility and repeatability of the method was very satisfactory with low value of RSD. The present method can be successfully applied for the study of sodium benzoate and caffeine in commercial soft drinks.Bangladesh Pharmaceutical Journal 19(1): 68-74, 2016

Challenges Associated with Sample Preparation for the Analysis of PBDEs in Human Serum

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in many applications; however, certain PBDE congeners are persistent, bioaccumulative, and toxic to both humans and the environment. PBDEs have been found in human specimens, and a variety of analytical techniques have been used for their determination in biological matrixes. Nevertheless, obtaining a relatively clean analytical blank sample during PBDE analysis is a big challenge because of the ubiquitous nature of these compounds. Thus, the present study was conducted to compare the PBDE background levels associated with the three most commonly used extraction techniques: liquid–liquid extraction (LLE), SPE, and accelerated solvent extraction (ASE). Conventionally used blank matrixes (HPLC grade water, Milli-Q water, and air) were spiked with internal standards and extracted using LLE, SPE, or ASE. The extracts were analyzed by GC/electron ionization-tandem MS. The ASE method achieved the lowest background levels for nearly all the PBDE congeners analyzed, which may be attributed to the stainless steel and closed-vessel nature of the ASE cells.

An Experimental Investigation of Heat Transport Capability in a Nanofluid Oscillating Heat Pipe

An experimental investigation of a nanofluid oscillating heat pipe (OHP) was conducted to determine the nanofluid effect on the heat transport capability in an OHP. The nanofluid consisted of HPLC grade water and 1.0vol% diamond nanoparticles of 5-50nm. These diamond nanoparticles settle down in the motionless base fluid. However, the oscillating motion of the OHP suspends the diamond nanoparticles in the working fluid. Experimental results show that the heat transport capability of the OHP significantly increased when it was charged with the nanofluid at a filling ratio of 50%. It was found that the heat transport capability of the OHP depends on the operating temperature. The investigated OHP could reach a thermal resistance of 0.03°C∕W at a heat input of 336W. The nanofluid OHP investigated here provides a new approach in designing a highly efficient next generation of heat pipe cooling devices.