LC-MS/MS Validation Analysis of Trastuzumab Using dSIL Approach for Evaluating Pharmacokinetics.

Quantitative targeted proteomics based approaches deploy state-of-the-art Liquid chromatography tandem mass spectrometry LC-MS technologies and are evolving as a complementary technique to standard ligand-binding based assays. Advancements in MS technology, which have augmented the specificity, selectivity and sensitivity limits of detection and freedom from antibody generation, have made it amicable towards various clinical applications. In our current work, a surrogate peptide based quantitative proteomics assessment is performed by selecting specific signature peptides from the complementary determining region CDR region of trastuzumab (Herclon®, Roche products in India). We developed a double Stable Isotope Label (dSIL) approach by using two different surrogate peptides to evaluate the proteolytic digestion efficiency and accurate quantification of the target analyte peptide of Herclon® in human serum. Method validation experiments were meticulously performed as per bioanalytical method validation guidelines. The dSIL approach, using an LC-MS/MS based quantification assay demonstrated good linearity over a range of 5-500 µg/mL of Herclon®, and validation experimental data is in compliance with bioanalytical regulatory guidelines.

Cyclodextrin based ternary system of modafinil: Effect of trimethyl chitosan and polyvinylpyrrolidone as complexing agents.

Modafinil is an approved drug for the treatment of narcolepsy and have a strong market presence in many countries. The drug is widely consumed for off-label uses and currently listed as a restricted drug. Modafinil has very low water solubility. To enhance the aqueous solubility of modafinil by the formation of a ternary complex with Hydroxypropyl-ß-cyclodextrin and two hydrophilic polymers was the main objective of the present study. Pyrrolidone (PVP K30) and a water soluble chitosan derivative, trimethyl chitosan (TMC) were studied by solution state and solid state characterization methods for their discriminatory efficiency in solubility enhancement of modafinil. Phase solubility study depicted the highest complexation efficiency (2.22) of cyclodextrin derivative in the presence of TMC compared to the same in the presence of PVP K30 (0.08) and in the absence of any polymer (0.92). FT-IR analysis of binary and ternary complex expressed comparable contribution of both polymers in formation of inclusion complex. The thermal behaviour of binary and ternary complex, involving individual polymers disclosed the influence of TMC on polymorphism of the drug. DSC study revealed efficiency of TMC to prevent conversion of metastable polymorphic form to stable polymorphic form. Ternary complex, involving TMC enhanced water solubility of the drug 1.5 times more compared to the binary complex of the drug whereas PVP K30 reduced the Solubility.

Chitosan as a suitable nanocarrier material for anti-Alzheimer drug delivery.

Chitosan, a biocompatible natural polysaccharide is frequently reported carrier material in targeted drug delivery to treat neurodegenerative disorders. Chitosan and its biodegradable products exert its bioactivities on nerve cells and blood brain barrier at the molecular level, which are beneficial in anti-Alzheimer therapy. Flexibility of surface modification, the ability to get attached with varieties of ligand molecules and the formation of the stable nano complex in physiological condition make chitosan an adorable material for delivery of anti-Alzheimer drugs and siRNA to the brain. The success rate of nose to brain delivery of anti-Alzheimer drugs enhances when chitosan used as a carrier material. This review covers direct and indirect anti-Alzheimer effects of chitosan, surface modification strategies to augment permeation from the blood-brain barrier structure, different ligands reported for brain targeting of chitosan nanoparticles containing anti Alzheimer drugs, blood compatibility and widely utilized chitosan nanoparticle fabrication techniques. Key intellectual claims are also condensed through patents to appraise chitosan as an attractive polymer for brain targeted nanoformulation which is currently facing oversight by regulatory agencies and manufacturers.

Development of forced degradation and stability indicating studies of drugs-A review.

Forced degradation is a degradation of new drug substance and drug product at conditions more severe than accelerated conditions. It is required to demonstrate specificity of stability indicating methods and also provides an insight into degradation pathways and degradation products of the drug substance and helps in elucidation of the structure of the degradation products. Forced degradation studies show the chemical behavior of the molecule which in turn helps in the development of formulation and package. In addition, the regulatory guidance is very general and does not explain about the performance of forced degradation studies. Thus, this review discusses the current trends in performance of forced degradation studies by providing a strategy for conducting studies on degradation mechanisms and also describes the analytical methods helpful for development of stability indicating method.

Development of forced degradation and stability indicating studies of drugs-A review / 药物分析学报

Forced degradation is a degradation of new drug substance and drug product at conditions more severe than accelerated conditions. It is required to demonstrate specificity of stability indicating methods and also provides an insight into degradation pathways and degradation products of the drug substance and helps in elucidation of the structure of the degradation products. Forced degradation studies show the chemical behavior of the molecule which in turn helps in the development of formulation and package. In addition, the regulatory guidance is very general and does not explain about the performance of forced degradation studies. Thus, this review discusses the current trends in performance of forced degradation studies by providing a strategy for conducting studies on degradation mechanisms and also describes the analytical methods helpful for development of stability indicating method.

Labeling of nucleosides with fluorescamine and detection by spectrofluorometer for End Stage Renal Disease.

Nucleosides are characterized as biomarkers in AIDS, Alzheimer, tumor, breast cancer and various malignant diseases. In the present work a direct method for the detection of nucleosides (adenosine, cytidine, uridine and guanosine) from urine samples has been developed. Nucleosides represent the extent of damage in genetic material, analysis of nucleosides by ultrasonic assisted microextraction effectively eliminates the interfering constituent of urine. This has made it a highly selective and sensitive method to analyze the nucleosides with a lower limit of detection 0.220 µmol/L and Limit of quantitation 0.660 µmol/L. The method has been validated with good linearity and correlation of coefficients of the calibration curves was higher than 0.997. The coefficients were in the range of 0.11-16.92% (inter-day) and 0.38-16.43% (intra-day), respectively.

Simultaneous monitoring of selective serotonin reuptake inhibitors in human urine, plasma and oral fluid by reverse-phase high performance liquid chromatography.

A simple and rapid reverse-phase high-performance liquid chromatography method is developed for the simultaneous determination of selective serotonin reuptake inhibitors (sertraline, citalopram, paroxetine and fluoxetine) in urine, plasma and oral fluid. Separation was performed on a Crestpack-18 column (4.6 × 250 mm × 5 µ) within 17.5 min. The mobile phase was composed of water (50 mL) [with glacial acetic acid (0.15 mL) + triethyl amine (0.30 mL)]-acetonitrile (40 mL)-methanol (10 mL), delivered isocratically (0.6 mL/min) at 270 nm. Liquid-liquid extraction was performed for isolation of analytes from biofluids. The developed methodology was validated in terms of sensitivity, linearity, accuracy, precision, stability and selectivity. The calibration curves were linear in the range of 5-1,000 ng/mL for all the compounds in three matrices, with coefficients of determination between 0.9991 to 0.9998. The average extraction recoveries for all the four analytes were above 90%. The limits of detection and limits of quantification were in the ranges of 0.02-1.20 and 0.12-2.51 ng/mL, respectively. The intra-day and inter-day variation coefficients were less than 8.0 and 11%, respectively. Moreover, the results were compared statistically for each analyte in three matrices and found to be equivalent, which signifies the absence of matrix effect. Thus, the method can be applied for the determination of selective serotonin reuptake inhibitors in urine, plasma and oral fluid for routine therapeutic and toxicological screening.

Optical nanobiosensor: a new analytical tool for monitoring carboplatin-DNA interaction in vitro.

The interaction of DNA and Carboplatin was studied with DNA labeled gold nanoparticles (AuNPs) based optical nanobiosensor. Carboplatin, a cytotoxic drug, is responsible for producing nephrotoxicity at effective dose. Thus, we have developed optical nanobiosensor for monitoring carboplatin-DNA interaction based on Fluorescence Resonance Energy Transfer (FRET) phenomenon. Paracetamol, an analgesic agent, was used as controlled drug in this study. The DNA labeled AuNPs, exposed to carboplatin, a binding event among the DNA and carboplatin takes place, resulting in a conformational change within the biosensor complex which decreases the distance among the fluorescent molecules or the fluorescent/quencher molecules. As the carboplatin interact with DNA, an increase in fluorescence intensity was observed. So, the major difference in increased fluorescence intensity between carboplatin-DNA and paracetamol-DNA interaction shows significant observations. Results have demonstrated that Optical sensor is able to rapidly and effectively monitor carboplatin-DNA interaction with a detection limit up to 0.45 µg/ml. This suggests that the developed optical nanobiosensor was ideal for monitoring Drug-DNA interaction studies while performing combinatorial synthesis for new drug development.

Solid lipid nanoparticles of a water soluble drug, ciprofloxacin hydrochloride.

The aim of this study was to understand and investigate the relationship between experimental factors and their responses in the preparation of ciprofloxacin hydrochloride based solid lipid nanoparticles. A quadratic relationship was studied by developing central composite rotatable design. Amount of lipid and drug, stirring speed and stirring time were selected as experimental factors while particle size, zeta potential and drug entrapment were used as responses. Prior to the experimental design, a qualitative prescreening study was performed to check the effect of various solid lipids and their combinations. Results showed that changing the amount of lipid, stirring speed and stirring time had a noticeable influence on the entrapment efficiencies and particle size of the prepared solid lipid nanoparticles. The particle size of a solid lipid nanoparticle was in the range of 159-246 nm and drug encapsulation efficiencies were marginally improved by choosing a binary mixture of physically incompatible solid lipids. Release of ciprofloxacin hydrochloride from solid lipid nanoparticle was considerably slow, and it shows Higuchi matrix model as the best fitted model. Study of solid lipid nanoparticle suggested that the lipid based carrier system could potentially be exploited as a delivery system with improved drug entrapment efficiency and controlled drug release for water soluble actives.

Introduction to fiber optics: Sensors for biomedical applications.

The paper focuses on the introduction of fiber optics, a fusion of science and engineering and describes the materials generally used for its construction along with the procedure used to design the fibers. It gives an idea of the materials used for the construction along with the pros and cons associated with them and various factors governing the emission of ultraviolet, infrared or visible radiations. The central core revolves around the applications of optical fibers in the medical and biomedical field and extending the use of the same in pharmaceutical industry as probes in quality control and dosage form analysis.

Nanosuspension: An approach to enhance solubility of drugs.

One of the major problems associated with poorly soluble drugs is very low bioavailability. The problem is even more complex for drugs like itraconazole, simvastatin, and carbamazepine which are poorly soluble in both aqueous and nonaqueous media, belonging to BCS class II as classified by biopharmaceutical classification system. Formulation as nanosuspension is an attractive and promising alternative to solve these problems. Nanosuspension consists of the pure poorly water-soluble drug without any matrix material suspended in dispersion. Preparation of nanosuspension is simple and applicable to all drugs which are water insoluble. A nanosuspension not only solves the problems of poor solubility and bioavailability, but also alters the pharmacokinetics of drug and thus improves drug safety and efficacy. This review article describes the preparation methods, characterization, and applications of the nanosuspension.

Histamine H4 receptor: a novel therapeutic target for immune and allergic responses.

HIstamine is a biomolecular compound located in various parts of body. It participated in various important cellular activities associated with allergy and asthma. This magic bio-molecule is directly and indirectly involved in various biochemical reactions through G-protein couple receptors. Various histamine receptors and their unexplored biochemical activities attracted many biologists in last few decades. A surprising discovery of histamine H(4) receptor was done when scientist worked on histamine H(3) receptor in brain cells. The binding pocket of histamine H(4) differs by transmembrane domains (TM3, TM5 and TM6) from histamine H(3)-sub type. In this review, we enlightened various functions of histamine H(4) and use of histamine H(4) receptor antagonists in autoimmune diseases, allergic responses, inflammatory responses, and in superoxide generation which are helpful to establish H(4) receptor antagonists as newer anti histamines.

A supercritical fluid chromatography/tandem mass spectrometry method for the simultaneous quantification of metformin and gliclazide in human plasma.

Present study reports the development and validation of a simultaneous estimation of metformin and gliclazide in human plasma using supercritical fluid chromatography followed by tandem mass spectrometry. Acetonitrile:water (80:20) mixture was used as a mobile phase along with liquid CO(2) in supercritical fluid chromatography and phenformin as an internal standard. The modified plasma samples were analyzed by electro-spray ionization method in selective reaction monitoring mode in tandem mass spectrometry. Supercritical fluid chromatographic separation was performed using nucleosil C(18) containing column as a stationary phase. The separated products were identified by characteristic peaks and specific fragments peaks in tandem mass spectrometry as m/z 130 to 86 for metformin, m/z 324 to 110 for gliclazide and m/z 206 to 105 for phenformin. The present method was found linear in the concentration ranges of 6.0-3550 ng/ml and 7.5-7500 ng/ml for metformin and gliclazide, respectively. Pharmacokinetic study was performed after an oral administration of dispersible tablets containing 500 mg of metformin and 80 mg of gliclazide using same techniques.

Anticounterfeit packaging technologies.

Packaging is the coordinated system that encloses and protects the dosage form. Counterfeit drugs are the major cause of morbidity, mortality, and failure of public interest in the healthcare system. High price and well-known brands make the pharma market most vulnerable, which accounts for top priority cardiovascular, obesity, and antihyperlipidemic drugs and drugs like sildenafil. Packaging includes overt and covert technologies like barcodes, holograms, sealing tapes, and radio frequency identification devices to preserve the integrity of the pharmaceutical product. But till date all the available techniques are synthetic and although provide considerable protection against counterfeiting, have certain limitations which can be overcome by the application of natural approaches and utilization of the principles of nanotechnology.

Chirality--a new era of therapeutics.

To develop the newer pharmaceuticals and to spur the strong growth, being a general property of 'handedness', chirality plays a major role. The Easson-Stedman principle shows the differences in the biological activity between enantiomers resulted from selective reactivity of one enantiomer with its receptor. It helps to improve the pharmacokinetic properties and to remove undesirable side effects by virtue of the unique activity of enantiomers. Racemic switching and marketing drug combinations are used as tools for drug life-cycle management and to redevelop racemic mixtures as single enantiomers.

Recent advances in the treatment of thromboembolic diseases: venous thromboembolism.

Venous thromboembolic diseases are the major concern of rising cost of healthcare and are commonest health problem across the globe. Both genetic and acquired risk factors are believed to be strongly linked with these diseases. Commonly encountered problems to the therapy include dose fixing and routine monitoring, yet some serious problems of bleeding also necessitate the immediate need to develop new agents. The review is primarily concerned with the new developments in the treatment of thromboembolic diseases. Therapeutic applications of anticoagulants, antiplatelets, and thrombolytics have been discussed in enough detail.

Dynamic instability at liquid/vapor interface far from equilibrium.

Attempt has been made to elucidate the mechanism of electric potential oscillations at oil-aqueous solution interface involving adsorption at oil-vapor interface on a semi-theoretical basis. The mechanism stipulates adsorption of ammonia, amines and pheromones at the liquid-vapor interface followed by transfer of ions through membrane-aqueous solution interface and subsequent interaction of ammonium (amine) ions and carbocations from pheromones with diffusing halide ions from the bulk. Relationship of the above mechanism with sensing mechanism of smell by olfactory nerves has also been pointed out.

Chiral chromatographic separation of beta-blockers.

A novel amide based chiral stationary phase m-[(+)-alpha-methyl benzyl carboxamide] XAD-4 has been synthesized by covalently linking R(+)-1-phenylethylamine to chloroformoyl Amberlite XAD-4 under weak alkaline conditions. The synthesized resin has been primarily characterized by m.p., elemental analysis and FT-IR and 13C NMR spectra. beta-Blockers viz. atenolol, metoprolol, and propranolol were successfully separated into their enantiomers using a mixture of sodium acetate-acetic acid buffer (pH 4.1):acetonitrile (4:6, v/v) solution using the synthesized resin. Hydrogen bonding and pi-pi interactions are supposed to be the major analyte-chiral stationary phase interactions.

Speciation, liquid-liquid extraction, sequential separation, preconcentration, transport and ICP-AES determination of Cr(III), Mo(VI) and W(VI) with calix-crown hydroxamic acid in high purity grade materials and environmental samples.

A new functionalized calix[6]crown hydroxamic acid is reported for the speciation, liquid-liquid extraction, sequential separation and trace determination of Cr(III), Mo(VI) and W(VI). Chromium(III), molybdenum(VI) and tungsten(VI) are extracted at pH 4.5, 1.5M HCl and 6.0M HCl, respectively with calixcrown hydroxamic acid (37,38,39,40,41,42-hexahydroxy7,25,31-calix[6]crown hydroxamic acid) in chloroform in presence of large number of cations and anions. The extraction mechanism is investigated. The various extraction parameters, appropriate pH/M HCl, choice of solvent, effect of the reagent concentration, temperature and distribution constant have been studied. The speciation, preconcentration and kinetic of transport has been investigated. The maximum transport is observed 35, 45 and 30min for chromium(III), molybdenum(VI) and tungsten(IV), respectively. For trace determination the extracts were directly inserted into the plasma for inductively coupled plasma atomic emission spectrometry, ICP-AES, measurements of chromium, molybdenum and tungsten which increase the sensitivity by 30-fold, with detection limits of 3ngml(-1). The method is applied for the determination of chromium, molybdenum and tungsten in high purity grade ores, biological and environmental samples. The chromium was recovered from the effluent of electroplating industries.

Calixarenes and their biomimetic applications.

The synthetic models for the structures, spectroscopic properties and catalytic activities of metalloprotein active sites have been reviewed. Calixarenes were used as new biomimetic catalysts because of their advantage of providing preorganiiation of the catalytic group, which can bind the substrate dynamically that results in fast turnover and fast release of the products. Functional and structural models based on calixarenes are presented and in addition importance of molecular recognition and non-covalent interactions e.g. hydrogen bonding and their role in biological systems are discussed with the help of synthetic systems.