Photodegradation of vitamin K₁ and K₂ injections during preservation and in intravenous admixtures was investigated by high-pressure liquid chromatography. When exposed to fluorescent light (500 lux), 50% of commercial product (10mg) of vitamin K₁ decomposed in about 15 days, compared with about 10 days for the 50% decomposition of vitamin K₂ product. In the intravenous admixtures for drip infusion, the residual rate after sunlight irradiation (2, 000 lux) for 3 hours was 43-63% for K₁ and 31-44% for K₂. Therefore, intravenous admixtures containing theselight-unstable injections require shading during drip infusion. In Osaka University Hospital, the light-resistant covers of containers for injections are used for this purpose.

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In order to monitor the plasma theophylline level in asthmatic patients given aminophylline intravenously, the efficiency of high-pressure liquid chromatography in measuring the blood level was examined. This method requires only 200μl of serum or plasma sample. It also produces satisfactory results in view of the lineality of the standard curve, precision and analytical recovery within a therapeutic level. In the clinical application, an ampule of Neophyllin (Eisai) was injected into an asthmatic patient intravenously. The blood level of theophylline was about 15.6μg/ml immediately after the injection and decreased to a half level after one hour. The half-life thereafter was about 8 hours.

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Grinding tablets is often required on dispensing. Weight loss in tablet content caused in that process was investigated with several uncoated and coated tablets. Two grinding methods, one using a mortar with pestle and the other using a tablet grinding machine, were conducted and the test results were compared with each other. The loss in weight varied depending on number of tablets employed: the larger the number of tablets becomes, the smaller the loss in weight is, and vice versa.
That tendency was observed in both methods. However, the loss in weight by the method using a mortar with pestle was always greater than that by the method using a tablet grinding machine. The loss in weight of the tablets on grinding in a mortar with pestle together with powder was smaller than that of the tablets without powder.

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The influence of the extract of lamb's gastric mucosa and citric acid on absorption of minocycline hydrochloride (MC-HCl) from the gastrointestinal tract was investigated after oral administration to humans. Serum and urine levels of MC-HCl were determined by thin layer horizontal diffusion method with Bacillus subtilis PCI-219. Each gram of the preparation used in this experiment contains 200 mg of the extract of lamb's gastric mucosa, 5 mg of citric acid, 10μg of cyanocobalamin and lactose as excipient; in addition, 15μg of zinc was also detected. The absorption of MC-HC1 given in dose of 200 mg was apparently inhibited by a single administration of this preparation (1g) or concomitant use of 200 mg of citric acid at the rate of 36.4% and 41.9%, respectively, 2 hours after administration. The action mechanism is not clear, but the absorption of MC-HCl was not inhibited at all by concomitant administration of this preparation and 5 mg of citric acid.

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Compatibility of Neuquion granules in combination with each of 31 adjuvant drugs was investigated in terms of change in appearance and weight. The mixtures, wrapped with white wax paper or polyethylene-laminated cellophan paper, were kept at 35° with relative humidity of 92% or 25° with 75%, respectively. Changes were examined immediately after compounding, and 2, 4, 7 and 14 days after. Some changes which could affect administration were observed in many combinations. But no significant changes attributable to the granules were detected. Marked change in appearance was seen after combination with Marzulene-S granule, but it was confirmed by thin layer chromatography that no chemical change took place between the two products.

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The activity of α-amylase, glucoamylase, protease, lipase and cellulase contained in such commercial multiple digestive enzyme preparations as Aczym, Excelase, Politose and Toughmac-E capsule was determined. These digestive enzymes were immersed in citric acid solution with a pH of 2.0 for 5 minutes and the loss rate of enzyme activity due to acidic environment was determined. Each digestive enzyme had characteristic activity against each substrate. However, all the four preparations showed a 100% loss in glucoamylase activity, while the loss rate of α-amylase, protease, lipase and cellulase ranged from 30 to 76%. Therefore, multiple digestive enzyme preparations should be coated with materials suitable for each enzyme contained in view of changing pH in digestive tract.

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