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 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.

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.

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).

High Pressure Liquid Chromatography of Ester and Salt Formulations of 2-Methyl-4-Chlorophenoxyacetic Acid

1979 ◽  
Vol 62 (4) ◽  
pp. 738-741
Author(s):  
Timothy Stevens ◽  
Robert B Grorud
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Collaborative Study ◽  
Internal Standard ◽  
Hplc Method ◽  
Hplc Assay ◽  
High Pressure Liquid Chromatographic ◽  
Chlorophenoxyacetic Acid ◽  
Liquid Chromatographic ◽  
Selection Of

Abstract A high pressure liquid chromatographic (HPLC) assay of amine salt and ester formulations of MCPA has been collaboratively studied. The AOAC 2,4-D HPLC method has been modified for application to MCPA products. The MCPA methodology is identical to that of 2,4-D except in strength of mobile solvent, pH of mobile solvent, heating of ester formulations to 50°C to ensure complete saponification, and the use of glass microfiber filters. The method is specific and separates all known impurities. Examination of chromatograms and percentage results from 8 collaborators indicate that selection of a practical internal standard would improve precision in the procedure and a second collaborative study is recommended.

High Pressure Liquid Chromatographic Determination of Vitamins A and E in Cereal Products

1979 ◽  
Vol 62 (3) ◽  
pp. 637-641
Author(s):  
Warren A Widicus ◽  
James R Kirk
Keyword(s):  
High Pressure ◽  
Direct Injection ◽  
Chromatographic Determination ◽  
Retinyl Palmitate ◽  
Tocopheryl Acetate ◽  
High Pressure Liquid Chromatographic ◽  
Cereal Products ◽  
Average Recovery ◽  
Liquid Chromatographic

Abstract A rapid method for the simultaneous determination of vitamins A and E in fortified cereal products has been developed. Saponification of retinyl or tocopheryl esters is not required, permitting direct injection of the extracted lipids onto the high pressure liquid chromatographic column without sample cleanup. Elution times of 2.46 and 3.40 min were determined for retinyl palmitate and tocopheryl acetate, respectively, using a μPorasil column and an isocratic mobile phase of hexane-chloroform (85+15) with a flow rate of 1.5 mL/min. The average recovery of retinyl palmitate was 99.2% (std dev. 4.28), and the average recovery of tocopheryl acetate was 94.9% (std dev. 4.10) in 2 cereals containing corn, oat, rice, and wheat. No significant amounts of naturally occurring tocopherols were found in the cereals.

Detection of Low-Level Carbadox Residues in Animal Feeds by High Pressure Liquid Chromatography

1977 ◽  
Vol 60 (2) ◽  
pp. 279-283
Author(s):  
Ronald G Luchtefeld
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
False Positive ◽  
Active Drug ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Low Level ◽  
Liquid Chromatographic ◽  
Positive Results

Abstract The high pressure liquid chromatographic (HPLC) method is capable of detecting from 1 to 0.024 ppm methyl 3-(2-quinoxalinyl-methylene) carhazate-Nl,N4-dioxido (carbadox). Carbadox is extracted from the feed with 2% NH4OH in acetone, passed through a liquid-liquid partition, subjected to HPLC, and detected by using a 365 nm detector. No feed materials or other active drug ingredients produced false positive results.

Quantitation of Radio-Labelled Vitamin K1 and Vitamin K1 Epoxide in Plasma by High Pressure Liquid Chromatography

1978 ◽  
Vol 39 (02) ◽  
pp. 466-473 ◽  
Author(s):  
Thorir D Bjornsson ◽  
Sarah E Swezey ◽  
Peter J Meffin ◽  
Terrence F Blaschke
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Vitamin K1 ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
Wide Range ◽  
Liquid Chromatographic

SummaryA convenient, accurate and reproducible high pressure liquid chromatographic method for the quantitation of radio-labelled vitamin K1 and vitamin K1 epoxide in plasma is described. The method involves the determination of total ether extractable radioactivity, and a chromatographic separation to determine the relative quantities of radio-labelled vitamin K1 and vitamin K1 epoxide. The method is useful over a wide range of ratios of the two compounds, and has a coefficient of variation of approximately 5%.

High Pressure Liquid Chromatographic Determination of Chloramine-T in Food

1979 ◽  
Vol 62 (5) ◽  
pp. 1087-1091
Author(s):  
Paul R Beljaars ◽  
Theo M M Rondags
Keyword(s):  
High Pressure ◽  
Ice Cream ◽  
Hplc Method ◽  
Complete Analysis ◽  
High Pressure Liquid Chromatographic ◽  
Digital Integrator ◽  
Relative Standard ◽  
Chloramine T ◽  
Minced Meat ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method for determining chloramine-T (N-chloro-N-sodium-p-toluenesulfonamide) in foods such as ice cream, minced meat, and shrimp is described. Deproteinized samples are treated with sulfite to convert chloramine-T to p-toluenesulfonamide (p-TSA) and extracted, and HPLC analysis is performed on concentrated extracts. Sample extracts are chromatographed on a reverse phase 10 μm Lichrosorb RP-18 column with acetonitrile-water (10+90), and quantitated by an ultraviolet detector (220 nm) and digital integrator. The relationship between recorded peak area and concentration was linear to 0.600 μg p-TSA/μL. The detection limit was 2.5 ng p-TSA/μL, corresponding to a chloramine-T concentration of 0.8 mg/kg in samples. Recoveries of added chloramine-T were 88% for ice cream, 73% for minced meat, and 51% for shrimp. Precision data indicate a relative standard deviation of 1.54 and 2.14% for the complete analysis of ice cream with levels of 15 and 63 mg chloramine-T/ kg (n = 5 determinations), respectively. The HPLC method was applied to chloramine-T determinations in 62 ice cream, 25 minced meat, and 25 shrimp samples.

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.

Sign in / Sign up

Export Citation Format

Share Document