M. Ajitha

The aim of the study was to develop colon targeted tablets of Sulfasalazine (SSZ) by wet granulation method using 33 Response surface method with design of experiment software and Eudragit RS 100, Eudragit RL 100-55, Ethyl cellulose and PVP K-30 as pH dependent polymers. All the formulations (F1 to F27) were evaluated for the physicochemical parameters and were subjected to in vitro drug release studies. The amount of Sulfasalazine released from tablets at different time intervals was estimated by UV spectrophotometer. The formulation F17 shown 98.21±1.15 of Sulfasalazine after 24 h, whereas marketed product drug release was 96.21±1.87 after 1 h. The results of the study showed that formulation F17 is the best formulation on the basis of drug release and other evaluation parameters. From in vivo bioavailability studies, after oral administration of colon targeted tablet containing 500 mg Sulfasalazine, the Cmax, Tmax, and AUC0–∞ of optimized formulation and marketed product was found to be 684.31±4.03 ng/mL, 6.01±0.04 h, 4525.12±2.02 ng*h/ mL and 702.26±3.23 ng/mL, 1.50±0.01h, 3335.18±2.02 ng*h/mL respectively. Cmax, Tmax and AUC values of optimized formulation were found to be significantly higher than of marketed product. The pH dependent system is a promising vehicle for preventing rapid hydrolysis in gastric environment and improving oral bioavailability of Sulfasalazine in the effective management of colon related diseases.

Single unit floating effervescent matrix tablets of Dipyridamole were successfully prepared with hydrophilic polymers like HPMC K4M , HPMC K15M and HPMC K100M with 10% NaHCO3 by Simple direct compression method with drug: polymer ratio of 1:1.5,1:2,1:2.5:1.3. FT-IR studies were conducted between drug, polymer and various excipients used in the formulations. Evaluation parameters of powder blend like Hausner’s ratio, Compressibility index, Angle of repose were carried out and results showed that the powder has good flow properties. Formulated tablets gave satisfactory results for various evaluation parameters like tablet hardness (5-6 Kg/cm2), weight variation (±10%), Friability (

  A novel, simple, selective and rugged quantitative method for the determination of Fenofibric acid the active metabolite of fenofibrate  in human plasma (Na2EDTA) using liquid chromatography-tandem mass spectrometric (LC-MS/MS) method has been developed and validated with 200µL human plasma. Fenofibric acid-d6 was used as an internal standard. Analyte and the internal standards were extracted from human plasma by liquid-liquid extraction using Methyl tertiary butyl ether as extraction solvent and ammonium acetate (5mM, pH 2.5) as extraction buffer. The reconstituted samples were chromatographed on a C18 column by using isocratic mobile phase. The method was validated over the concentration range of 79.89–20021.87 ng/mL. The Quattro Premier XE mass spectrometer was operated under the multiple reaction-monitoring mode (MRM) using the electro spray ionization technique for quantification of ion transitions at m/z 317.06/231.00 and 323.24/231.04 for the drug and the internal standard respectively. The method was validated for precision and accuracy, stability, matrix effect, dilution integrity, ruggedness, selectivity and extraction efficiency, and method has been proved to be simple, sensitive, selective, rugged and reproducible. A run time of 2.00 min for each sample made it possible to analyze more than 400 plasma samples per day. The proposed method can be applied for the estimation of the Fenofibric acid in real time plasma samples for pharmacokinetic, drug-drug interaction and toxicological studies.   Key words: Fenofibric acid, Validation, Human Plasma, LC-MS/MS, Electrospray ionization.

A simple, sensitive and rugged quantitative method for the determination of Clopidogrel in human plasma (K2EDTA) using liquid chromatography-tandem mass spectrometric (LC-MS/MS) method has been developed and validated. Clopidogrel-d3 was used as an internal standard. Analyte and the internal standards were extracted from human plasma by liquid-liquid extraction technique using Methyl tertiary butyl ether as extraction solvent and 0.5% formic acid as extraction buffer. The reconstituted samples were chromatographed on a C18 column by using acetonitrile / 5mM ammonium acetate (90/10, V/V) as the mobile phase. The method was validated over the concentration range of 101.98–61028.96 pg/mL. The Quattro Premier XE mass spectrometry was operated under the multiple reaction-monitoring mode (MRM) using the electrospray ionization technique for quantification of ion transitions at m/z 322.13/212.04 and 326.06/215.04 for the drug and the internal standard respectively. The results of the intra and inter batch precision and accuracy studies were well within the acceptable limits. The method has been proved to be simple, sensitive, fast, reliable, rugged and reproducible. A run time of 2.50 min for each sample made it possible to analyze more than 400 plasma samples per day. The proposed method can be applied for the estimation of the drug in real time plasma samples for pharmacokinetic studies. Key words: Clopidogrel, Validation, Human Plasma, LC-MS/MS, Electrospray ionization.