ABSTRACT
Buprenorphine is a partial mu agonist and kappa antagonist which is used for the treatment of pain and opioid addiction. A mixture of buprenorphine hydrochloride and naloxone hydrochloride has been approved for the treatment of opioid dependence. In this study a third order derivative spectrophotometric method based on zero-crossing technique has been used for the simultaneous determination of buprenorphine hydrochloride and naloxone hydrochloride in tablets. The measurements were carried out at wavelengths of 257.8 [zero-crossing point of naloxone hydrochloride] and 252.2 nm [zero-crossing point of buprenorphice hydrochloride] for buprenorphine hydrochloride and naloxone hydrochloride, respectively in the third order derivative spectra obtained in methanol and 0.1 M NaOH [50:50] as solvent. The method was found to be linear in the range of 20-80 micro g/mL for buprenorphine hydrochloride and 5-20 micro g/mL for naloxone hydrochloride. The within-day and between-day coefficient of variation and error values were less than 2.5% and 1.8%, respectively. The proposed method was successfully used for simultaneous determination of these drugs in pharmaceutical dosage form without any interference from excipients or need to prior separation before analysis
ABSTRACT
A mixture of acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride is used for the symptomatic treatment of common cold. In this study, a derivative spectrophotometric method based on zero-crossing technique was proposed for simultaneous determination of acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride. Determination of these drugs was performed using the [1]D value of acetaminophen at 281.5 nm, [2]D value of diphenhydramine hydrochloride at 226.0 nm and [4]D value of pseudoephedrine hydrochloride at 218.0 nm. The analysis method was linear over the range of 5-50, 0.25-4, and 0.5-5 microg/mL for acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride, respectively. The within-day and between-day CV and error values for all three compounds were within an acceptable range [CV<2.2% and error<3%]. The developed method was used for simultaneous determination of these drugs in pharmaceutical dosage forms and no interference from excipients was observed
Subject(s)
Spectrophotometry , Diphenhydramine/chemistry , Pseudoephedrine/chemistry , TabletsABSTRACT
In this study a sensitive, simple and accurate spectrophotometric method was suggested for determination of tamsulosin in bulk powder and pharmaceutical dosage form based on the formation of an ion-pair complex between the drug and bromocresol green in a buffer solution at pH 3.5. The formed yellow color complex was extracted with chloroform and measured at 415 nm. The optimum reaction conditions such as pH, reagent amount, extracting solvent and the stoichiometry of the ion-pair complex were investigated. Under the optimized conditions, the Beer's law was obeyed in the concentration range of 1-160 mg/mL with acceptable correlation coefficient [r2 > 0.9997] and precision [CV < 3%] and accuracy [error < 2%]. The proposed method was successfully used for the determination of tamsulosin in pharmaceutical capsule with no-significant interferences of excipients
ABSTRACT
A stability indicating High-Performance Liquid Chromatography [HPLC] method was validated and used to study the degradation of cetirizine dihydrochloride in acidic and oxidative conditions. The separation was carried out on a Symmetry C18 column and a mixture of 50 mM KH[2]PO[4] and acetonitrile [60:40 v/v, pH = 3.5] was used as the mobile phase. The method was linear over the range of 1-20 micro g/mL of cetirizine dihydrochloride [r[2] > 0.999] and the within-day and between-day precision values were less than 1.5%. The results showed that cetirizine dihydrochloride was unstable in 2 M HCl and 0.5% H[2]O[2]. The kinetics of the acidic degradation showed a pseudo-first-order reaction in the temperature range of 70-90[degree sign]C. In addition, the kinetics of hydrogen peroxide mediated degradation was pseudo-first-order in the temperature range of 50-80[degree sign]C
Subject(s)
Cetirizine/pharmacokinetics , Drug Stability , Cetirizine/metabolism , Reproducibility of ResultsABSTRACT
A Spectrophotometric method for determination of Cu [II] based on the complex formation with a new reagent 6-[2-naphthyl]-2,3-dihydro-as-triazine-3-thione[NDTT] is described. NDTT was synthesized based on the knowledge available for the preparation of 6-phenyl-2,3-dihydro-as-triazine-3-thione [PDTT]. Reaction of 2-acetylnaphthalene 1 with amyl nitrite gave 2-naphthylglyoxal aldoxime 2, which upon reaction with thiosemicarbazide yielded 6-[2-naphthyl]-2,3-dihydro-as-triazine-3-thione [NDTT] 3. NDTT produces a red complex with copper which is easily extractable with chloroform at pH>8 while the reagent is not extracted under these conditions. The absorption of the complex in the UV region [313 nm] is about 7 times greater than in the visible region [508 nm]. The mole ratio of the complex which is formed between Cu [II] and NDTT is 2:3, which was calculated by both the mole ratio and the continuous variation methods. The absorbance of the complex obeys Beer's law in the concentration range of 0.08-2 micro g Cu[II]/ml chloroform with r = 0.998 and detection limit of 13 ng/ml. This procedure can be carried out in the presence of many cations and anions in the presence or absence of the masking agents