The antiplatelet activity of Aspirin

The synthesis of aspirin in the late nineteenth century marked the development of what was to become the most widely used household analgesic in the twentieth century. However, with the increased understanding of the major role of platelets in vascular occlusion over the last ten years, the importance of aspirin as an antiplatelet drug and, consequently, its applications in reducing the risks of thrombotic vascular events, have received major attention.peer-reviewe

Controlled temperature storage of medicinals

What is an expiry date? Quite simply, it is an assurance that a medicinal product will meet applicable standards of identity, strength, quality and purity at the time of use. However, this assurance is not all-encompassing; it is only applicable under the storage conditions specified by the manufacturer on the labelling and packaging following extensive stability studies. Failure to provide for the storage conditions specified by pharmaceutical manufacturers invalidates this assurance and consequently, it is the responsibility of manufacturers, distributors, importers and dispensing pharmacists to ensure that adequate provisions are taken in their premises in this regard throughout the shelf life of the product.peer-reviewe

Flow-through dissolution testing : a comparison with stirred beaker methods

Dissolution testing of solid dosage forms is well-established as a standard technique to assess drug release from tablets and capsules. It is currently the most useful in vitro method for assuring batch-to-batch uniformity, and is a valuable quality control procedure for comparing release profiles of different batches of finished products.peer-reviewe

Pricing of medicinal products : considerations in a small market state

Thomas Szasz, the leading Hungarian psychiatrist, once stated: “Formerly, when religion was strong and science weak, men mistook magic for medicine; now, when science is strong and religion weak, men mistake medicine for magic.”peer-reviewe

Development and validation of HPLC-PDA assay method of frangula emodin

Frangula emodin, (1,3,8-trihydroxy-6-methyl-anthraquinone), is one of the anthraquinone derivatives found abundantly in the roots and bark of a number of plant families traditionally used to treat constipation and haemorrhoids. The present study describes the development and subsequent validation of a specific Assay HPLC method for emodin. The separation was achieved on a Waters Symmetry C18, 4.6 × 250 mm, 5 μm particle size, column at a temperature of 35 °C, with UV detection at 287 and 436 nm. An isocratic elution mode consisting of 0.1% formic acid and 0.01% trifluoroacetic acid as the aqueous mobile phase, and methanol was used. The method was successfully and statistically validated for linearity, range, precision, accuracy, specificity and solution stability.peer-reviewe

Comparison of the molecular weight distribution of gelatin fractions by size-exclusion chromatography and light scattering

Commercial gelatin is a heterogeneous proteinaceous product with a broad range of molecular weights. The use of gelatin to prepare insoluble nanoparticles depends largely on the presence of high molecular weight fractions that can be separated by size-exclusion chromatography. The purpose of this study was to determine the molecular fractions of gelatins from three commercial types (B225, B60 and A60), measure their molecular weight and compare these with data obtained from an absolute light scattering method. The mean molecular weight of the gelatins decreased in the order B225 > B60 > A60. All samples were polydisperse, with fractions varying from 2 MDa. Each sample was divided into eight fractions based on the molecular weight distribution and using a paired t-test the two methods were shown to be in substantial agreement. The light scattering method would appear to provide an absolute quality control procedure for commercial gelatin, depending on its application and requirements.peer-reviewe

Gelatin behaviour in dilute aqueous solution : designing a nanoparticulate formulation

Although it has been claimed that nanoparticles can be produced from gelatin, a naturally occurring polypeptide, the commercial conversion of animal collagen to gelatin results in a heterogeneous product with a wide molecular-weight range. This is probably responsible for the widely observed variation in the experimental conditions required for nanoparticle formation. In this study, 0.2% w/v aqueous B225 gelatin solutions were incubated under various conditions of time, temperature, pH and ethanol concentration and characterized by both size-exclusion high-performance liquid chromatography (HPLC) and dynamic light scattering. Gelatin was shown to be denatured when the temperature was increased to 37°C (approx.) and the rate of renaturation was optimized over the temperature range 7–20°Cat pH5.0, equivalent to the isoelectric point (IEP). The molecular-weight profile remained unchanged at 37°C (approx.) in the pH range 5–7. When the gelatin solutions were mixed with ethanol, higher-molecular-weight fractions (microgel, δ and ζ fractions, all with molecular weights > 700 kDa) precipitated at ethanol concentrations lower than those required to precipitate the lower molecular weight material (< 700 kDa), with maximum precipitation occurring close to the isoelectric point (pH 5.0). The molecular weight profile of gelatin in solution is evidently critically affected in a time-dependent manner by both pH and temperature. These two factors influence the noncovalent interactions responsible for the molecular structure of gelatin. The molecular weight profiles, in turn, affect the phase behaviour of gelatin in hydroalcoholic solutions. Systematically investigating the effect of time, temperature, pH and ethanol concentration on the molecular-weight-distribution profile of a gelatin solution enabled a robust method to be developed for the preparation of colloidal dispersions of non-aggregated gelatin nanoparticles 220–250 nm in diameter. This contrasts with the multiparticulate aggregates produced by earlier literature methods.peer-reviewe

The roles and responsibilities of the Qualified Person in the pharmaceutical industry

Malta’s accession into the European Union in May 2004 brought with it a number of changes within the local pharmaceutical industry. Foremost amongst these was the requirement for the holder of a manufacturing or import authorisation to have permanently and continuous at his disposal the services of one or more Qualified Persons (QPs).peer-reviewe

Laryngeal lymphoma : the high and low grades of rare lymphoma involvement sites

The larynx is an extremely rare site of involvement by lymphomatous disease.We present two cases of isolated laryngeal high-grade and another low-grade lymphoma, together with a literature review of laryngeal lymphoma management.peer-reviewe

2α,8α-Diacet­oxy-cis-himachalane

The title compound, C19H32O4, was synthesized from γ-himachalene, wich was isolated from essential oils of Cedrus atlantica. The mol­ecule is built up from two fused six- and seven-membered rings. The six-membered ring has a screw-boat conformation, whereas the seven-membered ring displays a half-chair conformation; the dihedral angle between the mean planes of the rings is 61.99 (6)°