Authors:Bugusu Nyamweru, Joseph Sempombe, Eliangiringa Kaale, and Thomas Layloff
A thin-layer chromatography (TLC) method for the analysis of clotrimazole was developed and validated according to the International Conference on Harmonization (ICH) and the United States Pharmacopeia (USP) guidelines. The developed method will be used for a qualitative and quantitative analysis of clotrimazole in vaginal tablets. The method was developed using mobile phase containing toluene-acetone (15:10 v/v) on precoated TLC silica gel 60 F254 glass plates at a detection wavelength of 215 nm using reflectance absorbance and saturation time of 20 min. Densitometric analysis showed clotrimazole being retained at RF of 0.27. The method had acceptable level of specificity where no interference was observed between clotrimazole peaks to that of blank. The calibration curve of clotrimazole was estimated using both linear and polynomial regression function in the range of 1000–2400 ng spot−1 with regression coefficient, r2, of 0.992 for linear and 0.999 for polynomial regression. The accuracy at nominal concentration of clotrimazole was found to be 99.14%, and % RSD was 1.13% for repeatability and 1.30% for intermediate precision that involved two analysts. The developed analytical method is useful for the determination of clotrimazole in the finished drug formulation. Also it helps to identify substandard and fake medicines labeled as clotrimazole during postmarketing surveillance of the drug and especially in resource-constrained countries.
Authors:Lensi Kumssa, Thomas Layloff, Ariaya Hymete, and Ayenew Ashenef
According to World Health Organization (WHO) 10% of the medicines in the Low and Middle Income Countries (LMICs) are of poor quality posing a major public health threat. One way to circumvent such problem is the development and deployment of rapid, economical and efficient analytical methods. Hence this research aims to develop a High-Performance Thin Layer Chromatography (HPTLC) method for the determination of doxycycline hyclate. A rapid and simple HPTLC method with densitometry detection at 360 nm to determine doxycycline hyclate in capsules and tablet formulations was developed and validated. HPTLC was performed on glass plates coated with C18 reverse phase silica gel 60 F254 and pretreated with 0.27 M ethylenediaminetetraaceticacid (EDTA) solution. The mobile phase was dichloromethane: methanol: acetonitrile: 1% aqueous ammonia in the ratio of 10:22:53:15 (v/v). The linearity range lies between 200 and 1,000 ng/spot with correlation coefficient of 0.997. The Rf value is 0.5 ± 0.02%. Recoveries were in the range of 94.50–100.5%. Limit of detection and limit of quantitation values for doxycycline hyclate were 40 and 160 ng/spot respectively. The developed method was validated as per ICH guidelines. Thus, it was found to be accurate, precise, specific and robust. In forced degradation study, doxycycline hyclate was found to degrade in acidic and alkaline media, and through oxidative stress. The drug was found to be relatively stable to heat and photo degradation. The method was successfully applied for the routine quantitative analysis of dosage forms containing doxycycline hyclate. The developed method offered comparable results (as confirmed by F-test) with that of the HPLC pharmacopoeial (BP) analysis method.