In Vitro Drug Release Studies of Metronidazole Topical Formulations Through Cellulose Membrane

Three different topical formulations namely gel, cream and ointment, each containing 1% w/w metronidazole, were prepared and in vitro permeation studies carried out. The permeation of metronidazole from each of the topical formulation was determined using dialyzing cellulose membrane in a dissolution tester. Glycerin, a permeation enhancer, was incorporated in varying concentrations and the amount of permeated metronidazole analysed using high performance liquid chromatography. The drug release was found to be greatest in the gel formulation followed by cream and ointment preparations in that order. Incorporation of glycerine enhanced drug release profile.Key words: Metronidazole formulation, in vitro studies, permeation, glycerin

Quality Performance of Drugs Analyzed in the Drug Analysis and Research Unit (DARU) during the Period 2006-2010

During the period 2006-2010, the Drug Analysis and Research Unit analyzed 583 samples. The samples comprised 50.6% local and 49.4% imported products. Samples were subjected to compendial or in-house specifications. The failure rate was 12.2% for local products and 14.2% for imports.  Antibacterial products recorded the highest failure rate (21.6%) while  anticancers and drugs acting on the gastrointestinal, respiratory and  reproductive systems all passed in the tests performed. The failure rate for antiprotozoals, antimalarials, antifungals, anthelminthics and analgesics was 14.3%, 12.5%, 11.8%, 8.9% and 11.5%, respectively.Key words: DARU, drug product, assay, dissolution, antimicrobial, antimalaria

Determination of hydroxyl groups in biorefinery resources via quantitative 31P NMR spectroscopy

The analysis of chemical structural characteristics of biorefinery product streams (such as lignin and tannin) has advanced substantially over the past decade, with traditional wet-chemical techniques being replaced or supplemented by NMR methodologies. Quantitative 31P NMR spectroscopy is a promising technique for the analysis of hydroxyl groups because of its unique characterization capability and broad potential applicability across the biorefinery research community. This protocol describes procedures for (i) the preparation/solubilization of lignin and tannin, (ii) the phosphitylation of their hydroxyl groups, (iii) NMR acquisition details, and (iv) the ensuing data analyses and means to precisely calculate the content of the different types of hydroxyl groups. Compared with traditional wet-chemical techniques, the technique of quantitative 31P NMR spectroscopy offers unique advantages in measuring hydroxyl groups in a single spectrum with high signal resolution. The method provides complete quantitative information about the hydroxyl groups with small amounts of sample (~30 mg) within a relatively short experimental time (~30-120 min)