Simple connector system for pressure ejection from multibarrel pipettes.

PURPOSE: To assess the accuracy and precision of methods in clinical use for intraocular drug injection. DESIGN: Experimental laboratory investigation. METHODS: A total of 800 injections were performed using 20 different 1-ml syringes at intended volumes of 0.10 ml and 0.05 ml. The volume of each injection was calculated from mass of water delivered onto an analytic balance. RESULTS: The mean measured volume delivered was less than the intended volume for every syringe (P <.001 for each syringe at each volume). A total of 7% and 22% of injections differed by 20% or more from the intended volumes of 0.10 ml and 0.05 ml, respectively. Overdelivery of volume was uncommon. CONCLUSION: Clinically relevant materials and methods used for intraocular injection of drugs systematically underdelivered the intended volume.

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PubMed2001

[A chemiluminescence flow sensor for vitamin B1].

AIM: To determine vitamin B1 in pharmaceutical preparations by chemiluminescence (CL) flow sensor. METHODS: When 200 microL of Na3PO4 was passed through an anion exchange column, K3Fe(CN)6 was eluted from the resin and then mixed with the vitamin B1 stream containing NaOH to product CL, by the fast oxidation reaction between vitamin B1 and K3Fe(CN)6 in alkaline solution. RESULTS: The CL emission intensity was correlated with the vitamin B1 concentration in the range 1.0 x 10(-5) to 1.0 x 10(-3) mol.L-1 and the detection limit was 8.0 x 10(-6) mol.L-1 (3 sigma). A complete analysis, including sampling and washing, can be performed within 2 min with a relative standard deviation of less than 4.0%. CONCLUSION: The vitamin B1 flow sensor was stable for over 200 analyses and has been applied successfully to determination of vitamin B1 in pharmaceutical preparations.

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PubMed2001

[Simultaneous determination of tryptophan, tyrosine and phenylalanine in injection by derivative fluorescent PLS method].

A new first-derivative fluorescent method by partial least squares (PLS) for the simultaneous determination of tryptophan, tyrosine and Phenylalanine was developed. The determination was carried out in KH2PO4-K2HPO4 buffer solution (pH = 7.4) and at the EX (excite) wavelength of 216.6 nm. The method has been applied to the determination of tryptophan, tyrosine and phenylalanine in compound amino acid injection, and the relative errors are within +/- 7.2%.

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