Method Development of Quality Control for Pharmaceutical Products

Abstract

Chloramphenicol eye drops collected from different manufacturers were exposed to sunlight and induced to heat and their potency values were determined by UV spectrophotometric method that produced incorrect high values because of the presence of degradation products. In separate experiments, the aqueous preparations of chloramphenicol (without any excipient) were subjected to 14 hours of sunlight exposure and 6 hours of heat induced at 100°C turning the sample color from yellowish to deep yellow. These heat-degraded and light exposed samples showed false-positive higher potency values as well as decreased efficacy against Salmonella typhi, Shigella dysenteries, Pseudomonas aeruginosa, Streptococcus agalactiae and Bacillus cereus by agar disc diffusion method. The values in the UV-spectrum of the standard, sunlight-exposed and heat-induced 11. ma, samples within the wavelength range 200 - 400nm were found at 278nm, 270nm and 274nm respectively indicating that the chloramphenicol aqueous solutions became degraded and converted into other degradation products. Different experiments suggested that direct measurement of chloramphenicol content by UV-spectrophotometer is not a correct approach. So, a combination of measurement methods performed by separation of the active fractions in TLC followed by UV-spectrophotometric method was proposed and also proposed a new method for potency determination of chloramphenicol using E. coli DH5a through agar disc diffusion method. In another study, a simple, reproducible and economical UV-spectrophotometric method was developed for the determination of ciprofloxacin from its tablet dosages form. The Standard curve of ciprofloxacin in the media of 0. ln HCI and distilled water were obtained by plotting absorbance versus concentration where calibration curve was found to be linear (R2>0.99) with optimum value of standard error for the entire analytical medium used. The percentage of potency of ciprofloxacin HCI in tablets from different companies were measured by this newly developed UV-spectrophotometric method. Comparing to the standard (99.77%), the values obtained (98.26%, 98.60% and 98.77%) were satisfactory indicating that UV-spectrophotometric method is perfect to determine the potency of ciprofloxacin tablet by taking the absorbance at 277nm for 0.1 N HCl at and 276 nm for distilled water as a diluting solution and these methods were found satisfactory results for the analysis of ciprofloxacin hydrochloride under the stress condition. A relative study for potency determination of ciprofloxacin tablet by high performance liquid chromatographic technique (HPLC) for the same companies showed a comparable result. So, this method for the potency determination by UV-spectrophometer could be used when HPLC is not available.