Buffer-free high performance liquid chromatography method for the determination of theophylline in pharmaceutical dosage forms

Abstract

Purpose: To develop and validate a simple, economical and reproducible high performance liquid chromatographic (HPLC) method for the determination of theophylline in pharmaceutical dosage forms. Method: Caffeine was used as the internal standard and reversed phase C-18 column was used to elute the drug and standard. The mobile phase was prepared by mixing water:acetonitrile:methanol at the ratio of 90:03:07 and the pH set at 4.6. Flow rate and ultraviolet (UV) detector were set at 1.0 mLmin-1 and 271 nm, respectively. The method was validated for linearity, recovery, accuracy, precision, specificity, and also for inter-day stability under laboratory conditions. Results: Retention time was 5.5 min. The limits of detection and quantification were 12.5 ngmL-1 and 100 ngmL-1, respectively. Recovery accuracy (%) for different concentrations ranged from 100.05 to 102.43; regression coefficient (R2) of 0.994; precision RSD < 2.0, and negligible interference from common excipients. Conclusion: The method is simple, rapid, highly specific and suitable for the determination of theophylline. Absence of buffer and use of small quantity of organic solvents increase the life span of the column and reduce the cost of routine analysis of theophylline in industry. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved.