International Journal of Pharmaceutical Sciences and Drug Research

01-13

Authors: Saurabh Srivastava, V. R. Sinha*

Injectable biodegradable polymeric microspheres of Stavudine were prepared using different viscosity grades of PLGA 50:50 (RESOMER® 504H and RESOMER® 502H) by solvent evaporation technique with different drug/polymer ratios. Tailored release of Stavudine facilitates reduction in symptoms of HIV infection and delay AIDS progression by reducing viral load to undetectable levels for extended period of time. The influence of formulation variables on microparticle characteristics like polymer type and concentration, vehicle type, polymer solution/vehicle volume ratio, surfactant concentration and drug to polymer ratios were evaluated. Microspheres were evaluated for yield, entrapment efficiency, particle size and in-vitro release behavior as well as characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), residual solvent analysis and confocal laser scanning microscopy (CLSM). Microspheres showed excellent surface topography with uniform distribution and structural integrity of the drug having the entrapment efficiency of 90.96 ± 1.09 and mean particle diameter below 65μm. Drug release kinetics data were obtained from various kinetic models and best explained by “Korsmeyer-Peppas equation” for both the polymers which depicted that drug release mechanism is anomalous transport, i.e. diffusion as well as polymer relaxation. Drug release from microspheres exhibited the characteristic release pattern of a monolithic matrix system with 90-100% drug release in 6-8 weeks demonstrating the feasibility of prolonged delivery of Stavudine using biodegradable microspheres for parenteral depot system.

18-22

Authors: A. B. Ruzilawati*, W. N. Wan Yusuf, N. Ramli, Z. Hussain, A. H. G. Rasool

A simple reverse-phase high-performance liquid chromatographic method has been developed for the determination of morphine in human urine using codeine as internal standard. After solid-phase extraction (SPE), the compounds were separated on a reversed-phase Acentis Express C18 column (150mm × 4.6mm, 2.7µm) equipped with a guard column (2.7 µm, 5 mm × 4.6 mm). The channel on the UV detector was configured to acquire data at 285 nm. The mobile phase was composed of acetonitrile-sodium acetate (pH 4; 0.01M) (10:90, v/v). The flow rate was 0.6 ml/min. Injection volume was 30 ml. The run time was set at 10 min. The retention time for morphine and codeine were approximately 3.4 min and 7.2 min, respectively. The calibration curve was linear over the concentration range of 150-2000 ng/ml with good linearity. Limit of detection (LOD) and quantification (LOQ) in urine were 50 and 150 ng/ml, respectively. Recovery was greater than 85%. The inter-day precision was from 9.27% to 12.53% and the intra-day precision ranged from 1.63% to 4.58%. The inter-day accuracy ranged 81.45% to 109.88% and intra-day accuracy ranged from 81.56% to 106.69%. The stability studies showed that morphine was stable up to one month in urine. This method was applied to determine morphine concentration in human urine for toxicology analysis.

28-31

Authors: Upadhyay Vipul, Sharma Neeru, Tiwari Kumar Amit, Joshi H. M., Malik Amreesh, Singh Brijpal, Kalakoti Singh Bahadur

Different extract of Convolvulus pluricaulis choisy, (Methanol, hydro-alcohol (50%) and water) were prepared and tested of scopoletin. The maximum scopoletin content was observed in 50% ethanolic extract followed by methanol and water extracts. It was 0.1738%, 0.0932% and 0.0435% in hydro-alcoholic, Methanol and water extract respectively. A simple HPLC (High Performance Liquid Chromatography) was developed for the determination of Scopoletin in Convolvulus pluricaulis choisy. Shankhpushpi is an astringent, hot aphrodisiac and a nervine tonic. It improves strength, digestive power, helpful in epilepsy, insomnia, heart disease and hemetemesis. Analyte separation and quantification were achieved by high-performance liquid chromatography (HPLC) and UV detection at 366 nm. The method involves the use of C18 column (Phenomenex, 250 mm × 4.6 mm, 5µm) with isocratic mixture of methanol and water containing 0.1% v/v formic acid in the ration of 30:70. Linearity was observed in the range of 20-100 ppm with correlation coefficient of 0.9961. Relative standard deviation of linearity of the method was found to be 1.29%. Detection limit was 5.0 ppm and quantification limit was 7.5 ppm. The repeatability of the method was found to be 0.71%. Recovery values from 99.10 to 100.1% indicate best accuracy of the method.

36-37

Authors: Kundan Kumar*, I. N. Mishra, Sandhya Jha

Escherichia coli strain ATCC 8739 is an important strain of pharmaceutical and biotechnological industries. We studied the viability of culture suspension of Escherichia coli strain ATCC 8739 at 2 to 8°C up to 360 days in 0.9% w/v NaCl. The culture suspension containing 10000 cfu/ml used in the study was stored at 2 to 8°C for 360 days in 0.9% w/v NaCl. Using 10µl of above culture suspension, the viable count was made by the pour plate technique using Soyabean Casein Digest Agar medium in fixed interval of time during the 360 days storage period. During the storage period, population of Escherichia coli strain ATCC 8739 decreased from 10000 cfu/ml to 9900 cfu/ml during the first 30 days, whereas the population decreased to 0 cfu/ml in 360 days. Findings emanate from the study indicates that 30 days storage period of Escherichia coli strain ATCC 8739 at 2 to 8°C in 0.9% w/v NaCl is suitable for laboratories testing purposes on account of fact that in 30 days storage period, population of Escherichia coli strain ATCC 8739 decreased from 10000 cfu/ml to 9900 cfu/ml which is very low.