Effect of solvent polarity on the extraction of components of pharmaceutical plastic containers

A study of the extraction of polymeric material and dyes from the pharmaceutical plastic containers using various organic solvents was conducted to evaluate the effect of polarity on the extraction process. The plastic containers used included semi-opaque, opaque, transparent and amber colored and the solvent used were acetonitrile, methanol, ethanol, acetone, dichloroethane, chloroform and water. The determination of extractable material was carried out by gravimetric and spectrometric methods. The yield of extractable materials from containers in 60 h was 0.10-1.29% [w/w] and the first-order rate constant [kobs] for the extraction of polymeric material ranged from 0.52-1.50 × 10[-3]min[-1] and for the dyes 6.43- 6.74 x10[-3]min[-1]. The values of [kobs] were found to be an inverse function of solvent dielectric constant and decreased linearly with the solvent acceptor number. The extractable polymeric materials exhibited absorption in the 200-400 nm region and the dyes in the 300-500nm region. The rates of extraction of polymeric material and dyes from plastic containers were dependent on the solvent dielectric constant. The solvents of low polarity were more effective in the extraction of material indicating that the extracted material were of low polarity or have non-polar character. The dyes were soluble in acetone and chloroform. No plastic material was found to be extracted from the containers in aqueous solution

Effect of stabilizers on the chemical and photodegradation of ascorbic acid in aqueous solution

Ascorbic acid [vitamin C] is susceptible to light and air and forms various degradation products. A number of stabilizers have been used to study their effect on the degradation of ascorbic acid [AH2] in dark and light at pH 4.0 and 6.0 alone and in combination with citric and tartaric acids. The assay of AH2 in degraded solutions was performed by a specific UV spectrometric method. The degradation product of AH2 at pH 4.0 and 6.0 was identified as dehydroascorbic acid. The degradation of AH2 has been found to follow first-order kinetics. The apparent first-order rate constants, t90 and percent inhibition in rate in the presence of stabilizers and the second-order rate constants for the interaction of stabilizers with AH2 have been determined. The highest stabilizing effect on AH2 was found by sodium metabisulfite, followed by sodium sulfite, sodium bisulfate, sodium thiosulfate and thiourea. The pH of the solutions has also been found to influence the degradation of AH2 as the rates are higher at pH 6.0 compared to those of pH 4.0, probably due to the ionization of AH2. A synergistic effect has been observed when citric or tartaric acid was added to the solutions containing stabilizers where citric acid showed comparatively better effect

review on the analytical techniques used for the determination of paracetamol in pharmaceutical formulations and biological fluids

Paracetamol [PM] is an active metabolite of phenacetin and belongs to p-aminophenol derivatives. It is also termed as acetaminophen. PM is one of the non-steroidal anti-inflammatory drugs [NSAIDs] which is used as an analgesic and antipyretic agent. It is an OTC drug and is used as a common household analgesic. It is not used as a substitute of aspirin or any other NSAIDs. It is a weak cyclooxygenase [COX] 1 and 2 inhibitor but may inhibit COX-3 in the central nervous system. Many analytical techniques have been used for the assay of PM in pharmaceutical preparations and biological fluids. These techniques include spectrometry, chromatography, spectrofluorimetry, chemiluminescence, electrochemical techniques, flow injection spectrometry and chronoamperometry. In many pharmaceutical preparations PM is also used in combination with other drugs and these techniques have also been used for their simultaneous determination. A detailed review of various analytical techniques used for the assay of PM has been carried out which would be of great help to the chemists and pharmacists involved in the analysis and quality control of drugs

Silicosis- a major occupational threat

One of the most hazardous diseases associated with the construction industry is silicosis, which is the outcome of dust inhalation. The prolonged breathing of silica [quartz] or silicon dioxide is considered as a potent irritant that causes the occurrence of this disease. The respiration of silica leads to the formation of scar tissue inside the lungs which diminishes the ability of lung to extract oxygen from air and hence leads towards the pulmonary fibrosis condition. In the present study, the workers engaged in bricks and tiles operation were examined and their percentage cell damage has been determined. According to the statistical analysis performed, there is no significant difference between the cell damage of the workers either employed in bricks or tiles operation and thus they are equally affected by the inhalation of silica. In addition, it has been found that there is a weak correlation between the length of the service of individual worker and the cell damage which signifies that intensity of silica exposure varies and is poorly correlated with the duration of work. However, when compared separately, the workers in both operations depict some interesting and surprising correlations

Multicomponent spectrometric assay of cyanocobalamin and its photoproduct hydroxocobalamin in the presence of ascorbic acid in photolyzed solutions

The simultaneous determination of cyanocobalamin [CC], hydroxocobalamin [HC] and ascorbic acid [AA] in aqueous solution has been achieved by a multicomponent spectrometric method. CC undergoes photolysis in acidic and alkaline media to form HC and the reaction is enhanced in the presence of AA. The method has been used to evaluate the kinetics of photodegradation reactions of the vitamin. CC, HC and AA present in the photolyzed solutions have been determined by absorbance measurement at 550, 525 and 265 nm at pH 4.0. These wavelengths correspond to the absorption maxima of the three substances and thus provide high specificity and sensitivity to the method. The method has been validated with respect to various parameters relating to the analytical performance characteristics. The recovery of the method for the three compounds ranges from 97.1-103.0% with a RSD value of +/- 3%. The accuracy of the method is shown by the linearity of the kinetic plots in the concentration range studied. The method is simple, rapid and convenient for the proposed work

Vitamin B[6]: Deficiency diseases and methods of analysis

Vitamin B[6] [pyridoxine] is closely associated with the functions of the nervous, immune and endocrine systems. It also participates in the metabolic processes of proteins, lipids and carbohydrates. Pyridoxine deficiency may result in neurological disorders including convulsions and epileptic encephalopathy and may lead to infant abnormalities. The Intravenous administration of pyridoxine to patients results in a dramatic cessation of seizures. A number of analytical methods were developed for the determination of pyridoxine in different dosage forms, food materials and biological fluids. These include UV spectrometric, spectrofluorimetric, mass spectrometric, thin-layer and highperformance liquid chromatographic, electrophoretic, electrochemical and enzymatic methods. Most of these methods are capable of determining pyridoxine in the presence of other vitamins and complex systems in micro g quantities. The development and applications of these methods in pharmaceutical and clinical analysis mostly during the last decade have been reviewed

Clinical significance and methods of analysis of vitamin A

Vitamin A is a group of unsaturated nutritional organic compounds, that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids, among which beta-carotene is the most important. Most compounds within the vitamin A family are soluble in fat and are essential for numerous processes within the body. Vitamin A [retinol] and derivatives play an essential role in metabolic functioning of the retina, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolk and the fat component of dairy products. It is required for normal vision, reproduction, embryonic development, cell and tissue differentiation and immune function in animals and humans. Vitamin A deficiency [VAD] is also known to be involved with different specific disease conditions such as xerophthalmia, polynephritis, keratomalacia and ulceration leading to irreversible blindness along with increased susceptibility to infections and abnormalities in reproduction. Vitamin A is sensitive to light and air and its ester forms are more susceptible to oxidation. The important analytical techniques used for the analysis of the vitamin A and its derivatives are high-performance liquid chromatography [HPLC], spectrophotometry and voltammetry. These methods have been found to be accurate and precise and have been applied successfully to the analysis of drug formulations

Stabilization of drugs in pharmaceutical preparations

Drug substances may undergo chemical degradation which may result in the loss of potency and therapeutic activity. Drugs are often sensitive to environmental and chemical factors such as oxygen, temperature, humidity, light, pH, ionic strength, solvent, buffers and excipients. The degraded products may produce undesirable effects as well as toxic effects on the body. The delivery of stabilized formulated products is a necessary requirement for the optimum efficacy of the active drug. The drugs are usually stabilized by chelating agents, complexing agents, bio-polymers, naturally occurring protectors, encapsulation of drugs and use of antioxidants. It has been found that hydrolytic and oxidative degradation are the main routes of loss of active ingredients. Solid preparations are usually stabilized by complex formation while in some liquid and semi-solid preparations there is a need to consider other factors such as pH, solvents for the stabilization of the drugs

Recent advancements in the clinical use of aspirin

Aspirin [acetylsalicylic acid] is a widely used drug that possesses analgesic activity. It is effective in the treatment of pain, inflammation and fever. In addition to these ailments aspirin has been found to be useful in the treatment of other diseases including cell apoptosis and colorectal cancer, Kawasaki disease, migraine and cardiovascular diseases. The mechanism of action of aspirin is due to its ability to suppress the production of prostaglandin and thromboxanes as a result of its irreversible inactivation of cyclo-oxygenase [COX] enzyme

Photodegradation of cyanocobalamin in the presence of ascorbic acid

The photodegradation of cyanocobalamin at pH 4.0 in the presence of ascorbic acid has been studied. Hydroxocobalamin has been identified as a major degradation product of the reaction. Cyanocobalamin and hydroxocoblamin in degraded solutions have been assayed at 550 and 525nm by a two-component spectrophotometirc method in which ascorbic acid does not interfere. The apparent first-order rate constants for the photodegradation of cyanocoblaamin at pH 4.0 are in the range of 2.21-2.70 x 10-3 min-1. These values indicate that the photodegradation of cyanocobalamin is enhanced in the presence of ascorbic acid by mutual interaction and needs protective measures to control the degradation of the vitamin

Physicochemical characteristics, biological functions and deficiency of cobalamins

Cobalamins are complex organometallic compounds of biological interest present in animal food products including meat, eggs and milk. The clinically important cobalamins, i.e. cyanocobalamin [vitamin Bl2], hydroxocobalamin and methylcobalamin exist as coenzymes in biological system and are involved in several biochemical functions. The deficiency of vitamin B12 occurs mainly due to its malabsorption and results in pernicious anemia. This disease is age related and is associated with the destruction of parietal cells in the stomach. Clinical studies with high dose supplementation of cobalamins suggest a strong correlation between the duration of cognitive symptoms of the disease and the therapy. Neural tube defects and other birth defects have also been reported with cobalamin deficiency

Biochemical functions and pharmaceutical and clinical analysis of nicotinamide

The major biochemical role of nicotinamide [vitamin 63] is its involvement in redox reactions and energy metabolism. The biological forms of nicotinamide are nicotinamide adenine dinucleotide [NAD] and nicotinamide adenine dinucleotide phosphate [NADP] coenzymes. Nicotinamide is a component of vitamin B-complex and is used in combination with other vitamin B compounds in pharmaceutical preparations. Several analytical methods have been used for the assay of nicotinamide in commercial products. These methods include high-performance liquid cinematography [HPLC], mass spectrometry in the multiple reaction modes [LC/UV/MS/MRM], liquid chromatographic-isotope detection mass spectrometry [LC/DMS], and planner chromatography-multiple detection by electro-spray mass spectrometry [ES/MS], capillary zone electrophoresis [CZE], thin-layer chromatography [TLC]-densitometry, differential pulse polarography and cyclic voltametry. The clinical analysis of nicotinamide involves the application of liquid chromatography-tandem mass spectrometry [LC-MS/MS], high-performance liquid chromatography [HPLC] and capillary electrochromatgraphy

Clinical analysis of vitamin D and metabolites

Vitamin D [mainly ergocalciferol and cholecalciferol] and their metabolites exist in a complex environment in biological systems. The identification and determination of the individual vitamin Ds in these systems require specific methods. The purified components of vitamin D can be determined by UV spectrometry and colorimetry. However the best method for the separation and determination of ergocalciferol and cholecalciferol and their metabolites is high-performance liquid chromatography. This technique in combination with mass spectrometry [LC-MS] can be used for the simultaneous separation and identification of vitamin D components and metabolites. The technique is also useful for the identification of vitamin D in steroidal mixture

Folic acid and deficiency diseases

Folic acid is a water-soluble vitamin, which is involved in hematopoiesis and the synthesis of amino acids and DNA. It is widely used for the treatment of megaloblastic anemia. Tetrahydrofolic acid is the fully reduced form of folic acid and is the parent compound of a variety of coenzymes that serve as carriers of one-carbon groups in metabolic reactions. The daily use of supplemental folic acid periconceptionally significantly reduces the risk of neural tube defects. The genetic polymorphisms affecting the structure-function of folate-related enzymes have been associated with the increased risk of birth defects and chronic diseases including vascular diseases and different types of cancers. Therapeutic use of folic acid has been found to greatly reduce the prevalence of these diseases