• Journal of Pharmaceutical Investigation
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• 제12권4호
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• pp.126-131
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• 1982

A quantitative fluorometric method was developed to determine aspirin and salicylic acid in bulk aspirin and commercial aspirin tablets. The excitation maximum for aspirin was observed at 280 nm and the emission maximum was at 335nm. The lowest energy excitation band for salicylic acid was at 308nm and the fluorescence emission band was at 450nm. Excipients, binders, lubricants and impurities did not interfere. Excellent recoveries were obtained for aspirin and salicylic acid. Results obtained by the KP III procedure and the proposed method were compared.

• Journal of Pharmaceutical Investigation
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• 제16권2호
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• pp.76-84
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• 1986

Berberine is one of alkaloids extracted from Phellodendri Cortex or Coptidis Rhizoma and has extensively used as an antibacterial and antidiarrheal drug. In order to increase the bioavailability of berberine preparation, berberine pamoate was synthesized and investigated on its usage in vitro and in vivo. Berberine was more rapidly extracted from herbal plants by hot water extraction method than soxhlet extraction method. Berberine pamoate was easily synthesized from berberine hydrochloride and potassium pamoate solution and identified using the infrared spectrum. Quantitative analysis of berberine was possible in methanol solution by fluorometric determination. The dissolution rate of berberine pamoate was more decreased than that of berberine hydrochloride in simulated gastric fluid and simulated intestinal fluid. The remaining proportion of berberine pamoate in the small intestine of rat was maintained at high concentration for a long time as compared with that of berberine hydrochloride.

• 한국가축번식학회지
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• 제9권2호
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• pp.133-139
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• 1985

An immunoassay may be defined as an analytical procedure involving the competitive reaction between a limiting concentration of specific antibody and two populations of antigen, one of which is labelled or immobillized. The advent of immunoassay has revolutionised our knowledge of reproductive physiology and the practice of veterinary and clinical medicine. Radioimmunoassay (RIA) was the first of these methods to be developed, which meausred the analyte with good sensitivity, accuracy and precision (1,2). The essential components of RIA are:-(i) a limited concentration of antibodies, (ii) a reference preparation, and (iii) an antigen labelled with a radioisotope (usually tritium or iodine-125). Most procedures invelove isolating the antibody-bound fraction and measuring the amount of labelled antigen. Good facilities are available for scintilltion counting, data reduction nd statistical analysis. RIA is undergoing refinement through:-(i) the introduction of new techniques to separate the antibody-bound and free fractions which minimize the misclassification of labelled antigen into these compartments, and the amount of non-specfic binding. (3), (ii) the development of non-extration for the measurement of haptens (4), (iii) the determination of a, pp.rent free (i.e. non-protein bound) analytes (5), and (iv) the use of monoclonal antibodies(6). In 1968, Miles and Hales introduced in important new type of immunoassay which they termed immunora-diometric assay (IRMA) based on t도 use of isotopically labelled specific antibodies(7) in a move from limited to excess reagent systems. The concept of two-site IRMAs (with a capture antibody on a solid-phase, and a second labelled antibody to a different antigenic determinant of the analyte) has enabled the development of more sensitive and less-time consuming methods for the measurement of protein hormones ovar wide concentration of analyte (8). The increasing use of isotopic methos for diverse a, pp.ications has exposed several problems. For example, the radioactive half-life and radiolysis of the labelled reagent limits assay sensitivity and imposes a time limit on the usefulness of a kit. In addition, the potential health hazards associated with the use and disposal of radioactive cmpounds and the solvents and photofluors necessary for liquid scientillation counting are incompatable with the development of extra-laboratory tests. To date, the most practical alternative labels to radioisotopes, for the measurement of analytes in a concentration > 1 ng/ml, are erythrocytes, polystyrene particiles, gold sols, dyes and enzymes or cofactors with a visual or colorimetric end-point(9). Increased sensitivity to<1 pg/ml may be obtained with fluorescent and chemiluminescent labels, or enzymes with a fluorometric, chemiluminometric or bioluminometric end-point. The sensitivity of any immunoassay or immunometric assay depends on the affinity of the antibody-antigen reaction, the specific activity of the label, the precision with which the reagents are manipulated and the nonspecific background signal (10). The sensitivity of a limited reagent system for the measurement of haptens or proteins is mainly dependent upon the affinity of the antibodies and the smalleest amount of reagent that may be manipulated. Consequently, it is difficult in practice to improve on the sensitivity obtained with iodine-125 as the label. Conversely, with excess reagent systems for the measurement of proteins it is theoretically possible to increase assay sensitivity at least 1000 fold with alternative luminescent labels. To date, a 10-fold improvement has been achieved, and attempts are being made to reduce the influence of other variables on the specific signal from the immunoreaction.