Chloroquine reduces urinary excretion of cloxacillin when it is administered concurrently with ampicillin-cloxacillin combination

Purpose: To investigate a possible effect of chloroquine on urinary excretion of cloxacillin when chloroquine is administered concurrently with ampicillin-cloxacillin combination. Methods: Eight healthy adult volunteers received single oral doses of Ampiclox® (ampicillin-cloxacillin combination) alone and in combination with chloroquine in a cross-over study design with one week washout period between the drug administrations. Total urine voided was collected from each volunteer at predetermined time intervals for a period of 9 hr. The urine was analyzed for cloxacillin by a reversed-phase HPLC method. Results: A significant reduction in the amount of cloxacillin excreted in urine was observed following the co-administration of chloroquine and the ampicillin-cloxacillin combination products. The mean total amount of cloxacillin (Du¥), maximum peak of excretion (Dumax) and % dose excreted after Ampliclox® was administered alone were 84.6 ± 57.0 mg, 49.5 ±41.6 mg and 33.9 ± 22.7% respectively. The corresponding values after co-administration with chloroquine were 30.2 ± 27.2 mg, 13.5 ± 10.4 mg and 12.1 ±10.9%. The respective times of maximum absorption (Tmax) and elimination half-life (t1/2) of cloxacillin were 2.7 ± 0.4 hr and 0.7 ± 0.4 hr after Ampiclox® alone and 1.5 ± 0.8 hr and 0.6 ± 0.5 hr after co-administration of the two drugs. The results showed a significant decrease (p < 0.0001) in the mean total amount as well as % dose of cloxacillin excreted in urine by 64% and a significant reduction (p < 0.05) in the Tmax of excretion by 45%. Conclusion: There is appreciable reduction in the urinary excretion of cloxacillin when given concurrently with chloroquine. The mode of this interaction and possible therapeutic implication is unknown. However, caution should be exercised when prescribing or administering these two drugs together. Key words: Drug-drug interaction, bioavailability, chloroquine, cloxacillin Tropical Journal of Pharmaceutical Research 2003; 2(1): 169-17

Design of an Intelligent Poultry Feed and Water Dispensing System Using Fuzzy Logic Control Technique

Prohibitive cost of production and laborious human involvement in poultry farms in the tropics could lead to low profit yield and low return on investment. Unfortunately, over-involvement of humans in the feeding system of poultry could lead to disease outbreak, undue fatigue and malnutrition of birds. These flaws in the poor feeding system of birds prompted this research work by developing an intelligent fuzzy logic based system that could mimic the roles of the poultry attendants in delivering water and feed dispensing for birds at specified time intervals. Water and feed level in the trough would be sensed by the designed system and dispense intelligently with respect to the variations in water and feed level as birds consume the feed and water. This system reduces workload of the poultry attendants, increases cost benefits and generates better return on investment in a deep litter poultry farming system Keywords: Microcontroller, Fuzzy Logic, Artificial Intelligence, Poultry Control System, Intelligent Water Dispensing, Deep Litter Syste

Improved Colorimetric Determination of Reserpine in Tablets Using 4-Caboxyl-2,6-dintrobenzene diazonium ion (CDNBD)

Purpose: To develop a simple, rapid and improved colorimetric method for the assay of reserpine in tablets Method: The method is based on the aromatic ring coupling of reserpine with 4-carboxyl-2,6dinitrobenzene diazonium ion with the consequent formation of an azo adduct. Optimization of reaction conditions and validation were carried out and the method applied to assay of reserpine in tablets. Result: Reserpine coupled readily with CDNBD and optimization of experimental conditions showed the reaction to be completed in 10 min at room temperature. A 1:1 drug to reagent stoichiometric ratio was obtained for the azo adduct formed. The adduct exhibited a bathochromic shift with respect to the drug and pronounced hyperchromic shift with respect to the reagent. Sample analyses were done using a colorimeter at 470 nm. The assays were linear and reproducible over the concentration range of 2.25 24 μg/mL. The new method was successfully applied in the assay of reserpine in tablets with a performance similar to the official (USP) spectrophotometric method (p > 0.05). This method represents a profound improvement on the previously reported colorimetric method for reserpine. Conclusion: The method developed is rapid and could find application in in-process quality control of reserpine

Research Article - Evaluation of Dimethylformamide (DMF) as an Organic Modifier in Hydrophobicity Index (Rm) Determination

Purpose: Ideal behaviour of mixtures of organic modifier and water is reflected by a linear relationship between refractive index and fraction of organic modifier in the mixture. This study was carried out to investigate dimethylformamide (DMF) as an organic modifier in hydrophobicity index (Rm) determination. Method: We quantitatively evaluated the problem of partial miscibility of phases associated with the reversed phase thin layer chromatographic (RPTLC) system, using liquid paraffin as stationary phase and acetone/water mixtures as mobile phase. Ideality of behaviour of acetone/water mixtures was investigated by refractive index measurements. Rm values of compounds were determined using mixtures of acetone and water as mobile phase. Results: DMF/water mixture behaved ideally across the whole concentration range investigated (0-100%) while acetone/water mixture deviated from ideal behaviour when the concentration of acetone in the mixture was 80%. DMF also gave a better extrapolation of Rm value from linear regression of partition data than acetone for bezafibrate used as a test-drug molecule. Conclusion: DMF is a better organic modifier than acetone in this RPTLC system. These findings could be extended to drug-receptor and drug design studies. The use of dimethylformamide (DMF) in preference to acetone as organic modifier is proposed in this study

Improved Colorimetric Determination of Reserpine in Tablets Using 4-Caboxyl-2,6-dintrobenzene diazonium ion (CDNBD)

Purpose: To develop a simple, rapid and improved colorimetric method for the assay of reserpine in tablets Method: The method is based on the aromatic ring coupling of reserpine with 4-carboxyl-2,6dinitrobenzene diazonium ion with the consequent formation of an azo adduct. Optimization of reaction conditions and validation were carried out and the method applied to assay of reserpine in tablets. Result: Reserpine coupled readily with CDNBD and optimization of experimental conditions showed the reaction to be completed in 10 min at room temperature. A 1:1 drug to reagent stoichiometric ratio was obtained for the azo adduct formed. The adduct exhibited a bathochromic shift with respect to the drug and pronounced hyperchromic shift with respect to the reagent. Sample analyses were done using a colorimeter at 470 nm. The assays were linear and reproducible over the concentration range of 2.25 24 μg/mL. The new method was successfully applied in the assay of reserpine in tablets with a performance similar to the official (USP) spectrophotometric method (p > 0.05). This method represents a profound improvement on the previously reported colorimetric method for reserpine. Conclusion: The method developed is rapid and could find application in in-process quality control of reserpine

Research Article - Chloroquine reduces urinary excretion of cloxacillin when it is administered concurrently with ampicillincloxacillin combination

Purpose: To investigate a possible effect of chloroquine on urinary excretion of cloxacillin when chloroquine is administered concurrently with ampicillin-cloxacillin combination. Methods: Eight healthy adult volunteers received single oral doses of Ampiclox® (ampicillincloxacillin combination) alone and in combination with chloroquine in a cross-over study design with one week washout period between the drug administrations. Total urine voided was collected from each volunteer at predetermined time intervals for a period of 9 hr. The urine was analyzed for cloxacillin by a reversed-phase HPLC method. Results: A significant reduction in the amount of cloxacillin excreted in urine was observed following the co-administration of chloroquine and the ampicillin-cloxacillin combination products. The mean total amount of cloxacillin (Du¥), maximum peak of excretion (dumax) and % dose excreted after Ampliclox® was administered alone were 84.6 ± 57.0 mg, 49.5 ±41.6 mg and 33.9 ± 22.7% respectively. The corresponding values after co-administration with chloroquine were 30.2 ± 27.2 mg, 13.5 ± 10.4 mg and 12.1 ±10.9%. The respective times of maximum absorption (Tmax) and elimination half-life (t1/2) of cloxacillin were 2.7 ± 0.4 hr and 0.7 ± 0.4 hr after Ampiclox® alone and 1.5 ± 0.8 hr and 0.6 ± 0.5 hr after co-administration of the two drugs. The results showed a significant decrease (p < 0.0001) in the mean total amount as well as % dose of cloxacillin excreted in urine by 64% and a significant reduction (p < 0.05) in the Tmax of excretion by 45%. Conclusion: There is appreciable reduction in the urinary excretion of cloxacillin when given concurrently with chloroquine. The mode of this interaction and possible therapeutic implication is unknown. However, caution should be exercised when prescribing or administering these two drugs together

4-Carboxyl-2, 6-dinitrobenzene diazonium ion (CDNBD): a new diazonium for the detection of phenol ether homologues

Pharmaceutical phenol ethers are a heterogeneous group of compounds possessing ether linkage to an aromatic nucleus. Diazo coupling is rare with these compounds and no physicochemical method of analysis has been reported based on the reaction of these ethers with a diazonium ion. The high reactivity of 4-carboxyl-2,6-dinitrobenzene diazonium ion (CDNBD) is therefore investigated in this work. Comparative coupling reaction was done with two other diazonium ions (derived from p-nitroaniline and sulphanilic acid). Twenty-two phenol ethers were selected for evaluation of their reactivity with the three diazonium ions. Such ethers consist of those with naphthalenes, indole and bridged rings. Spot tests were used to establish coupling at room and elevated temperatures. Visual inspection and thin layer chromatographic (TLC) analysis of the reaction mixture provided evidence of coupling or otherwise. UV-VIS absorption spectra were used to characterize brightly coloured adducts, as a preliminary test for the estimation of these ethers by spectrophotometry. Of all the ethers screened, fourteen gave instant and distinct colour from CDNBD while seven of these gave colours of deeper intensity at elevated temperature. Only three of the ethers gave instant colour with diazotized p-nitroaniline while one compound gave instant colour with diazotized sulphanilic acid. UV absorption spectral analysis reveals the superiority of CDNBD for the detection and possible estimation of these ethers. CDNBD is shown to be a highly reactive arenediazonium ion with the possibility of finding usefulness for the determination of phenol ethers by ultraviolet/visible spectrophotometry and precolumn derivatization in high performance liquid chromatographic (HPLC) analysis. Journal of Pharmacy & Bioresources Vol. 2(2) 2005: 146-16