Background: Cinnarizine, an antihistaminic drug, is commonly formulated in combination with domperidone and with paracetamol for treatment and prevention of motion sickness and migraine. Objective: The aim of this work was to develop new, simple, precise and selective chromatographic methods (RP-HPLC and TLC-densitometric methods) for the determination of these drugs. These methods can be used as analytical tools in the routine examination in quality control laboratories. Methods: The first method was RP-HPLC method, the separation was carried out on an Inertsil® ODS- 3V C18 column (250 mm × 4.6 mm, 5 µm) using a mobile phase composed of methanol: acetonitrile (45: 55, v/v) at a flow rate of 1 ml/min. The detection was carried out at 220 nm. The second method was a TLC-densitometric method where the studied components were separated using a developing system composed of toluene: ethyl acetate: methanol: triethylamine (5: 4.3: 0.7: 0.5, v/v/v/v) on TLC silica gel 60 F254 plates, followed by densitometric scanning at 270 nm. Results: In RP-HPLC method, the peaks were sharp and well separated, the retention times were 5.25, 3.48 and 2.78 min, for cinnarizine, domperidone and paracetamol, respectively. Linearity was obtained over the concentration ranges 1-22, 0.75-16.5 and 25-550 µg/ml, for cinnarizine, domperidone and paracetamol, respectively. In TLC-densitometric method, good separation of spots and linear relationships were achieved over the concentration ranges of 0.2-2, 0.15-1.5 and 5-50 µg/spot, for cinnarizine, domperidone and paracetamol, respectively. Method validation was conducted according to ICH guidelines in terms of linearity, accuracy, selectivity, precision and robustness. Conclusion: The developed methods were applied for the determination of the cited drugs in tablets containing binary drug mixtures. The methods are simple and precise and can be used for routine analysis of the labelled drugs in combined dosage forms in quality control laboratories.
Objectives: The objective of the present study was to check the potential presence of illicit drugs and to quantify the amount of nicotine in a buccal tobacco brand that had been observed to be increasingly used by Yemeni youths, since 2014, causing narcosis resembling states among them. Methods: Thin-layer chromatography (TLC) described by the United Nations Office on Drugs and Crime (UNODC) was used to screen illicit drugs in the tested brand. The illicit drugs investigated included opiates, heroin, amphetamines, and cocaine. The TLC results were confirmed as recommended by the UNODC using color chemical tests. Identification and quantification of nicotine in the brand was carried out using an appropriate high-performance liquid chromatography (HPLC) system. Results: No illicit drug was found in the tested tobacco brand. On the other hand, it was found that the amount of nicotine in just a single dose (sachet) of the buccal brand was 17.67±0.901 mg, which was 3.53-fold greater than usual buccal dose of nicotine (5 mg). Conclusion: With the exception of cannabis, opioids, and hallucinogens that were not investigated in this study due to technical obstacles, other major illicit narcotic drugs are not found in the brand. The brand contains high amount of nicotine/sachet. However, knowing that the user may use more than one sachet of the brands a day, there is a great potential of nicotine overdosing due to intake of the brand. This may cause a narcosis resembling state called “Nesbitt’s paradox,” characterized by reducing neuronal activity of the user.
Objectives: The aim of this study was to compare in vitro dissolution of cefixime in a pharmacopeial-recommended medium and in simulated gastrointestinal fluids. Methods: Before dissolution testing, the drug content in the tested materials was determined by ultraviolet spectrophotometer. The dissolution media used in this study were recommended by the United States Pharmacopeia (USP) as well as four different media that mimic gastric and intestinal fluids in fed and fasted states. The tested materials included the pure drug and two 0.2-g capsule brands (original and test). Results: The pharmacopeial medium showed no difference in both extent and rate of the drug dissolution between the tested materials. In the contrary, the difference was significant when the simulated fluids were used. Moreover, it was found that the simulated intestinal fluid (SIF) of fed state showed 21–32% decrement in the drug dissolution compared to that of the corresponding fasted-state simulated fluid. Indeed, this finding agreed those of in vivo bioavailability studies published in literature. Conclusion: The SIF is much more valid as a medium for in vitro testing of cefixime capsule than the one recommended by the USP.
Objectives: The aim of this work was to develop and validate new, simple, accurate, and selective spectrophotometric methods (derivative and derivative ratio spectrophotometric methods) for the determination of these drugs. These methods can be used as analytical tools in routine examination in quality control laboratories. Methods: The first method was derivative method in which the first derivative method (1D) for determination of PCM and the second derivative method (2D) for determination of CIN. The second method was the first derivative ratio spectrophotometric method (1DD) for determination of CIN and PCM. Results: In first method, the first derivative spectrum (1D) of PCM where PCM was determined by measuring the amplitude of the valley at 235 nm while CIN showed zero crossing spectrum, and the second derivative spectrum (2D) of CIN where CIN was determined by measuring the amplitude of the peak at 287.5 nm while PCM showed a zero value. In the second method, the first derivative ratio spectrophotometry (1DD) for CIN and PCM determination, where the amplitude at 290 and 291 nm, was selected for the determination of CIN and PCM, respectively. Conclusions: The developed methods were applied for the determination of the cited drugs in tablets containing binary drug mixture. The methods are simple and precise and can be used for routine analysis of the labeled drugs in combined dosage forms in quality control laboratories.
Background: Etamsylate (ETS), a haemostatic drug, is formulated with mefenamic acid (MFA) for pain relief. Objective: The aim of this work was to develop chromatographic methods for the estimation of ETS and MFA in the presence of their main impurities. These methods could be used in the routine analysis in quality control laboratories. Methods: The first method was RP-HPLC method, the separation was carried out on an Inertsil® ODS- 3V C18 column using a mobile phase composed of acetonitrile: potassium dihydrogen phosphate buffer adjusted to pH 7 with 0.1 N NaOH (55: 45, v/v) at a flow rate of 1 ml/ min. The detection was carried out at 220 nm. The second method was a TLC-densitometric method where the studied components were separated using a developing system composed of dichloromethane: ethyl acetate: methanol: triethylamine (6: 2: 2: 0.5, v/v/v/v) on TLC silica gel 60 F254 plates, followed by densitometric scanning at 300 nm. Results: In RP-HPLC method, the peaks were sharp and well separated, good retention times were obtained. Linearity was obtained over the concentration range 20-90 µg/ml, for both ETS and MFA. In the TLC-densitometric method, well separation of drug spots and linear relationship were achieved over the concentration range of 0.4-2.8 µg/spot, for both ETS and MFA. Method validation was conducted according to ICH guidelines. Conclusion: The developed methods were applied for the determination of the cited drugs in laboratory prepared mixtures and in tablets containing the two drugs. The methods are simple and precise and can be used for routine analysis of the drugs in combined dosage forms in quality control laboratories.
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