Current Pharmaceutical Analysis - Volume 3, Issue 2, 2007

The manufacture of coagulation Factor VIII concentrates fractionated from human plasma is subjected to a set of stringent quality control tests and quality assurance procedures. These requirements apply to all stages of product development and production, from the selection and quality control of the starting plasma source material to the purification, viral inactivation, storage and distribution phases of the final product in its pharmaceutical form. The present review addresses the major in-vitro and in-vivo analytical methods important to assess the potency, quality, and safety of coagulation Factor VIII products and to detect the presence of unwanted contaminants such as proteolytic enzymes and endotoxins.

In recent years, many studies have been developed with the aim of improving drug detection in both conventional specimens and alternative biological matrices. A large number of drug abuse studies, forensic toxicology analyses, drugs in the workplace and even in doping control in sports activities related to drug detection in biological samples have been reported in the literature. The interest in the development and optimization of analytical techniques to detect drugs of abuse in different specimens is explained by the several possibilities and information that they can provide. Conventional samples such as urine and blood and more recently, saliva and sweat, are of fundamental importance whenever recent exposure to drugs is under investigation. Human keratinized tissues such as hair and nails are especially important for obtaining data of chronic long-term exposure with the great advantage of being collected in a non-invasive way. Meconium can be a useful biological sample to evaluate fetal drug exposure following maternal drug use. This paper reviews chromatographic procedures for determination of amphetamines, cannabinoids, opiates, nicotine, cocaine and alcohol in alternative biological matrices. Gas chromatographic and liquid chromatographic procedures with different detectors (including mass spectrometry) and sample preparation techniques such as liquid-liquid extraction (LLE), solid phase extraction (SPE) and solid phase microextraction (SPME) were considered.

Multifunctional polymers are highly promising auxiliary agents for the oral delivery of a broad variety of drugs. The main features of multifunctional polymers include controlled release, mucoadhesive, cohesive and permeation enhancing properties and enzyme as well efflux pump inhibitory properties. Within the current review, the most important multifunctional polymers for oral drug delivery as well as various analytical methods including the rotating cylinder method, tensile studies, confocal laser scanning microscopy, permeation studies, and also enzyme and efflux pump inhibition studies are discussed.

Hyaluronic acid is a glycosaminoglycan, which is one of the main components of the extracellular matrix, contributes significantly to cell proliferation and migration, and is involved in many physiological and pathological biologic processes, such as the progression of some malignant tumors. Therefore, the determination of its amounts may be of use for monitoring the progress of some diseases and/or as prognostic/diagnostic marker. Hyaluronan has been used for the therapy of osteoarthritis, for ophthalmic and cosmetic surgeries, and is under investigation for numerous other diseases. In this review, after a short introduction to hyaluronan structure and biologic roles, the electrophoretic, chromatographic and solid-phase assays used for determination of its concentration in biologic samples and in drug formulations are presented.

Chronic obstructive pulmonary disease (COPD) is characterized by diffuse inflammation of the airways and parenchyma of the lung. In its most devastating form, the disease produces widespread emphysematous changes in the lung, characterized by dilatation and rupture of alveoli, marked impairment of gas exchange, and eventual respiratory failure. The development of therapeutic agents for COPD, and pulmonary emphysema in particular, has been hampered by the lack of clinical or biochemical tests which can rapidly and reliably determine drug efficacy. The only recognized endpoint for evaluating new treatments, pulmonary function studies, may take years to detect a significant effect. This delay is due to the fact that pulmonary emphysema progresses at a relatively slow rate, and the available methods for measuring the loss of lung function are not particularly sensitive. Since elastic fiber degradation is an important feature of pulmonary emphysema, the authors propose measuring specific breakdown products of these fibers in sputum as a more immediate means of monitoring therapeutic interventions. In addition to facilitating rapid evaluation of new forms of treatment for pulmonary emphysema, this assay might also prove to be a useful screening procedure for persons who smoke or otherwise have a greater than normal risk of developing this disease.

Interactions between lipoproteins and vascular endothelium are considered to be a central component of the pathogenesis of atherosclerosis and cutaneous xanthomas. It is widely accepted that the binding of oxidized low-density lipoprotein to cell membrane receptors activates an intracellular signal transduction pathway that produces adhesion molecules on the surface of endothelial cells. Circulating monocytes adhere to these molecules and subsequently migrate across the cell membrane into the lesions. Growing evidence indicates that the mechanisms of adhesion molecule expression vary depending on the oxidation process of low-density lipoprotein and the organ specificity of the endothelial cells. This review summarizes recent studies involving the induction of adhesion molecule expression in vascular endothelial cells by oxidized low-density lipoprotein, with special attention to the pharmaceutical, biochemical, and clinical applications of this process.

An electroanalytical method was developed for the direct quantitative determination of phenazopyridine hydrochloride (PAP) or in other words, pyridium, in spiked human urine and tablet dosage forms. The electrochemical reduction and determination of PAP were carried out at carbon paste electrode (CPE) in various aquaeous solution in the pH range of 0.5-12.30 by (CV) and osteryoung square wave voltammetry (OSWV). The best results were obtained for the quantitative determination of PAP by OSWV method in 0.5 mol L-1 sulfuric acid at about pH 0.51. The peak current and peak potential depend on pH and scan rate were studied. The diffusion controlled nature of the peak was established. This electroanalytical procedure made it possible to determine PAP in the concentration range 2.5x10-8-2.5x10-6 mol L-1. Limit of detection (LOD) and limit of quantification (LOQ) were obtained as 7.5x10-9 and 2.5x10-8 mol L-1 respectively. Precision and accuracy of the developed method were checked by recovery studies in spiked urine and tablet dosage forms.

Venoms of the viperidae (vipers and pit vipers) snakes are rich sources of proteinases which render fibrinogen incoagulable and solubilize fibrin. Many of these compounds have profound effects (stimulating or inhibiting) on the hemostatic mechanism, including, blood coagulation cascade, fibrinolysis, hypotension, vascular integrity and platelet function. The lethality of a venom often appears to be due to the combined action of several of these components, but severe consequences are frequently connected with hemostatic disorders. Viperid snake bite accidents in human and other large animals are characterized by localized or generalized bleeding and or thrombotic sequelae. This review is focused on the structural properties and features of a number of South American snake venom enzymes possessing clearly defined (pro)fibrinolytic activity. Under physiological conditions the venom proteins active on the plasminogen/fibrinolytic system can be grouped into two main categories: 1) direct-acting fibrinolytic endoproteinases which are related in amino acid sequence to the major family of metalloproteinases known as the metzincins. The members of this group are zinccontaining metalloproteinases (SVMPs) varying in size from 20 to 100 kDa and often more than one example is present in the same venom. 2) serine proteinases which specifically activate plasminogen into plasmin, and contain at least one catalytic domain structurally similar to trypsin. A number of these proteinases have been isolated and their mechanism of action established. Both direct and indirect endoproteinases on their own are practically nontoxic; however, they may act synergistically with other factors aggravating their toxic effects. Moreover, these proteinases are characterized by a relatively high degree of substrate specificity and resistance to physiological inhibitors. Indeed, some of these venom components are thought to hold promise as agents for medical applications in the field of thrombosis and diagnosis, or to hold the key for the design of pharmaceuticals.