Pilocarpine Hydrochloride in Ophthalmic Solutions: Modification of a High-Pressure Liquid Chromatographic Determination and Survey

1976 ◽  
Vol 59 (6) ◽  
pp. 1409-1415
Author(s):  
John D Weber
Keyword(s):  
High Pressure ◽  
Cation Exchange Resin ◽  
Chromatographic Determination ◽  
The United States ◽  
Hplc Method ◽  
Buffer System ◽  
High Pressure Liquid Chromatographic ◽  
Drug Substances ◽  
Liquid Chromatographic ◽  
Ophthalmic Solutions

Abstract Pilocarpine undergoes 2 important reactions in solutions, epimerization to isopilocarpine and hydrolysis to pilocarpic acid. There is no official USP limit for isopilocarpine or pilocarpic acid in pilocarpine hydrochloride ophthalmic solutions. An existing high-pressure liquid chromatographic (HPLC) method was modified by changing the buffer system to permit its use with constant-pressure as well as constant-volume instruments. The procedure separates all 3 components on a cation exchange resin ; pilocarpine and isopilocarpine are determined directly and pilocarpic acid indirectly. Ophthalmic solutions and drug substances were obtained from substantially all the United States marketers of pilocarpine opthalmic solutions and were analyzed by the modified HPLC method. Results of the survey show that isopilocarpine is present to the extent of 0.4–3% and pilocarpic acid at levels of 0.6–7% of total alkaloid.

High Pressure Liquid Chromatographic Determination of Monensin in Feed Premixes

1983 ◽  
Vol 66 (2) ◽  
pp. 284-286
Author(s):  
Thomas D Macy ◽  
Andrew Loh
Keyword(s):  
High Pressure ◽  
Coefficient Of Variation ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Average Recovery ◽  
Bioassay Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method has been developed to determine monensin in feed premixes. The method is simple and rapid. Monensin is extracted with methanol-water and determined in the extracting solution by HPLC. Average recovery for monensin from a 13.2% premix sample was 103% (coefficient of variation (CV), 2.6%) by HPLC and compares with the value of 100% (CV, 3.4%) obtained by the turbidimetric bioassay method.

High Pressure Liquid Chromatographic Assay for Prednisone in Bulk Drug Substances and Tablets

1983 ◽  
Vol 66 (2) ◽  
pp. 264-272 ◽  
Author(s):  
Robert E Graham ◽  
Edward R Biehl ◽  
Margarito J Uribe
Keyword(s):  
High Pressure ◽  
Coefficient Of Variation ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Average Recovery ◽  
Drug Substances ◽  
Blue Tetrazolium ◽  
Bulk Drug ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method was developed for the assay of prednisone in bulk drug substances and tablets. The sample was dissolved in water-methanol and an aliquot was analyzed by using HPLC. The average recovery of prednisone added to a prednisone tablet composite was 99.5% with a coefficient of variation of 1.07%. Prednisone was determined in 46 tablets (1-50 mg prednisone/tablet) formulated by 22 manufacturers, using the HPLC method and the USP blue tetrazolium assay. The results show that the HPLC method is more specific and faster than the USP method.

High Pressure Liquid Chromatographic Determination of Ethopabate in Feeds

1977 ◽  
Vol 60 (5) ◽  
pp. 1048-1050
Author(s):  
Leonard R Schronk ◽  
Billy M Colvin ◽  
Alan R Hanks ◽  
Rodney J Bushway
Keyword(s):  
High Pressure ◽  
Limit Of Detection ◽  
Colorimetric Method ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Hplc Method ◽  
Detector Response ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method is described for determining ethopabate in poultry feeds. Feed samples containing ethopabate are finely ground, extracted 30 min by sonification with methanol-water (80+20), and filtered. The extract is cleaned up on an alumina column, and the first 4 ml eluate collected is analyzed. The drug is eluted through a μBondapak C18 column with acetonitrile-water (30+70) at a flow rate of 1.4 ml/min and detected by ultraviolet absorption at 280 nm. Chromatography is complete in 7 min, and detector response is linear. The drug is quantitated by peak height ratios. The procedure described is reproducible and shows good agreement with the official AOAC colorimetric method. The lower limit of detection is 2 ng by HPLC, making the method applicable to residue analyses.

High Pressure Liquid Chromatographic Determination of Sulfamethazine in Pork Tissue

1982 ◽  
Vol 65 (6) ◽  
pp. 1311-1315
Author(s):  
Byron L Cox ◽  
Leo F Krzeminski
Keyword(s):  
High Pressure ◽  
Methylene Chloride ◽  
Trisodium Citrate ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Edible Tissues ◽  
Aqueous Mixture ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method has been developed for determination of sulfamethazine residues in pork liver, kidney, muscle, and fat. The sample was extracted with acetone- chloroform, concentrated in the presence of dilute HC1, and partitioned between dilute HC1 and hexane. The acid solution was washed with methylene chloride and then buffered with trisodium citrate and sodium hydroxide to pH 5.8-5.9. Sulfamethazine was extracted from the aqueous mixture with methylene chloride, concentrated, dissolved in buffer, and eluted from XAD-2 resin with methanol. Sulfamethazine was reliably quantitated at 0.1 ppm by HPLC on a Zorbax ODS column with detection at 254 nm with no interference from tissues or reagents. The average recovery from the edible tissues, i.e., liver, muscle, kidney, and fat, fortified at 0.1-0.4 ppm was 85.6 ± 3.7%.

High Pressure Liquid Chromatographic Determination of Sucrose in Honey

1977 ◽  
Vol 60 (4) ◽  
pp. 838-841 ◽  
Author(s):  
James E Thean ◽  
Walter C Funderburk
Keyword(s):  
High Pressure ◽  
Membrane Filter ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Field Samples ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Refractive Index Detector

Abstract A normal phase high pressure liquid chromatographic (HPLC) method is presented for separating and determining sucrose in honeys. This method has been successfully applied to the analysis of field samples containing sucrose (0.63–8.44 wt %). Diluted honeys are filtered through a 0.45 μm membrane filter, and injected directly into the chromatograph. Samples are eluted from a μBondapak/carbohydrate column with acetonitrile-water (83+17) and quantitated with a refractive index detector. Average recovery of sucrose is 97%.

Reverse Phase High Pressure Liquid Chromatographic Determination of Vitamin K1 in Infant Formulas

1983 ◽  
Vol 66 (5) ◽  
pp. 1063-1066
Author(s):  
Martin P Bueno ◽  
Melina C Villalobos
Keyword(s):  
High Pressure ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
Vitamin K1 ◽  
Infant Formulas ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A reverse phase high pressure liquid chromatographic (HPLC) method for quantitating vitamin K1 in enzymatic hydrolysates of infant formula is described. The vitamin is extracted with n-pentane before determination by isocratic and isothermal reverse phase HPLC. Recovery of vitamin Ki added io 5 infant formulas ranged from 84 to 103%

High Pressure Liquid Chromatographic Determination of Uncombined Intermediates and Subsidiary Colors in Orange B

1977 ◽  
Vol 60 (5) ◽  
pp. 1067-1069
Author(s):  
Manjeet Singh
Keyword(s):  
High Pressure ◽  
Thin Layer ◽  
Sulfonic Acid ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Good Agreement

Abstract A high pressure liquid chromatographic (HPLC) method has been developed for isolating and determining uncombined intermediates and subsidiary colors in Orange B. Samples of Orange B containing 0.1–0.3% naphthionic acid, 0.05–0.2 % phenylhydrazine-p-sulfonic acid, 0.2–0.8% pyrazolone-T and ethyl ester of pyrazolone-T, 0.2–1.0% 3-[(4-sulfo-l-naphthalenyl)-azo]-4-amino-l-naphthalenesulfonic acid, and 0.1–6.0% Orange K were prepared and analyzed by using this method. Recoveries ranged from 95 to 103%, except for the phenylhydrazine-p-sulfonic acid which ranged from 95 to 140%. Ten samples of Orange B were analyzed by conventional column and thin layer chromatographic methods as well as by the HPLC method. Good agreement was obtained for naphthionic acid, Orange K, and naphthionic acid plus the naphthionic acid subsidiary.

High Pressure Liquid Chromatographic Determination of Pentachlorophenol by Using Paired Ion Chromatography Reagents

1979 ◽  
Vol 62 (5) ◽  
pp. 1004-1006
Author(s):  
Elmer H Hayes
Keyword(s):  
High Pressure ◽  
Mobile Phase ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Steel Column ◽  
Stainless Steel Column ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method for determining pentachlorophenol in formulations is described. Samples containing pentachlorophenol are accurately weighed in suitable volumetric flasks and diluted with dioxane. The sample is then injected onto a stainless steel column containing μBondapak C18. The mobile phase is 60% methanol/PIC A and 40% water/PIC A. This method is simple and eliminates many of the extractions required in other methods of analysis.

High Pressure Liquid Chromatographic Determination of Aflatoxins in Corn

1979 ◽  
Vol 62 (3) ◽  
pp. 586-594 ◽  
Author(s):  
Walter A Pons
Keyword(s):  
High Pressure ◽  
Silica Gel ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Extraction Solvent ◽  
Normal Phase Hplc ◽  
Liquid Chromatographic Determination ◽  
Water Saturated ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method is proposed for determining aflatoxins in corn. The sample is extracted with methanol-10% NaCl (4+1) , pigments are precipitated with zinc acetate, and the extract is cleaned up on a small (2 g) silica gel column. Aflatoxins in the purified extract are resolved by normal phase HPLC on a microparticulate (10 μm) silica gel column with water-saturated chloroform-cyclohexane-acetonitrile solvent, and detected by fluorescence on a silica gel-packed flowcell. The method was compared with chloroform-water extraction of the official CB method on 15 samples of contaminated corn. In 5 of the 6 samples containing aflatoxins B1, B2, G1, and G2, methanol-10% NaCl extracted more aflatoxin than did cloroform-water, as measured both by HPLC and by thin layer chromatography. In samples containing only B1 and B2, the 2 extraction solvents were virtually equivalent. Agreement was good between HPLC and TLC for each extraction solvent. Average recovery of aflatoxins Bl, B2, Gl, and G2 added to yellow cornmeal at 3 levels was >90%.

Liquid Chromatographic Determination of Lasalocid in Premixes

1978 ◽  
Vol 61 (5) ◽  
pp. 1070-1073
Author(s):  
Robert B Hagel
Keyword(s):  
High Pressure ◽  
Coefficient Of Variation ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Insoluble Material ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method has been developed to determine lasalocid in premixes. The method is simple and rapid, requiring an extraction of the drug and separation of insoluble material before HPLC. Elution times are typically <10 min per sample. The average recoveries for lasalocid at the 16.5 and 50% levels were 100.2±2 and 100.0±2%, respectively. The precision of the method (coefficient of variation = 0.02) compares favorably with that of the approved bioassay (coefficient of variation = 0.06).

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