Development and validation of a uv-spectrophotometric method for the quantitative determination of oxcarbazepine and study of its degradation profile

Oxcarbazepine (OXC) has attracted much attention owing to its multiple health benefits. OXC is an anticonvulsant and mood stabilizing drug, used primarily in the treatment of epilepsy. This study developed and validated a simple, specific, sensitive and reliable stability indicating UV-Spectrophotometric method for the quantitative determination of oxcrbazepine in pure and in pharmaceutical dosage forms. Analysis was performed using methanol: aceonitrile (50:50) as diluents. UV detection was performed at 254 nm. The calibration plot was linear over a concentration range of 0.0-15 µg ml-1 with correlation coefficient values >0.9986. The method was validated for specificity, linearity, precision, accuracy, limit of detection, limit of quantification and robustness. The forced degradation studies were performed by using HCl, NaOH, H2O2, thermal and UV radiation. Oxcarbazepine is more sensitive towards alkaline conditions and very much resistant towards acidic, oxidative and photolytic degradations. The method was validated as per ICH guidelines. The RSD for intra- and inter-day precision were found to be lesser than 3. The percentage recovery was in good agreement with the labeled amount in the pharmaceutical formulations and the method is simple, specific, precise and accurate for the determination of oxcarbazepine in pharmaceutical formulation

Sensitive spectrophotometric method for the determination of olanzapine and orphenadrine in pure and dosage forms by ternary complex formation with eosin and lead(II)

The present paper describes a simple and sensitive spectrophotometric method for the determination of olanzapine (OLZ) and orphenadrine (ORP) in pure and in dosage forms. The developed method is based on ternary complex formation of drugs under investigation with eosin and lead(II) using methyl cellulose as surfactant. The formed ternary complex which shows maximum absorbance (λmax) at 540 nm for both drugs OLZ and ORP, respectively. The optimum experimental conditions for the ternary complex formation were established. The Beer’s law is obeyed in the concentration ranges, 0.0-35.0 and 0.0-55 μg/mL for both methods. The molar absorptivity values for methods A and B were found to be 1.03 × 104 and 0.51 × 104 L mol-1 cm-1, respectively with the corresponding Sandell’s sensitivity values 0.0303 and 0.0602 μg cm-2. The proposed methods were further applied to the determination of OLZ and ORP in bulk and in pharmaceutical preparations via standard addition technique. No interference was observed from the common adjuvants added to the tablets which are applicable for the assay of the investigated drugs in different dosage forms

Highly sensitive spectrophotometric method for the quantitative determination of olanzapine in its pure and in pharmaceutical dosage forms

The present paper describes a simple, accurate and highly sensitive visible spectrophotometric method for the determination of olanzapine in pure drug and in pharmaceutical formulations. The proposed method is based on the formation of a colored charge - transfer complex by two steps. In the first step, N-bromosuccinimide (NBS) oxidize olanzapine into its sulphoxide form, and in the second step, unreacted NBS oxidize metol to form p-N-methylbenzoquinonemonoimine (PMBQMI) which reacts with isonicotinic acid hydrazide (INH) to form a colored complex and the resulting colored complex exhibit a maximum absorption peak at 610 nm. Beer's law was obeyed over the concentration range 0.4 - 8.0 μg ml-1 and the calculated molar absorptivity is 2.08 � 104 l mol-1cm-1; and the corresponding limit of quantification (LOQ) was 0.3696 μg ml-1. All the variables were studied in order to optimize the reaction conditions. No interference from the excipients added to tablets was found. The results obtained in the proposed method has been compared statistically to the reference method and found to be simple, accurate (t-test) and reproducible (F-test) and can be used as an alternative for simple and routine determination of olanzapine in microgram quantities in industrial quality control laboratories

Spectrophotometric estimation of nitrazepam in pure and in pharmaceutical preparations

Three simple, sensitive, accurate, and rapid visible spectrophotometric methods (A, B, and C) have been developed for the estimation of nitrazepam in both pure and in pharmaceutical preparations. They are based on the diazotization of reduced nitrazepam with nitrous acid followed by coupling with acetyl acetone (method A), diphenylamine (method B), and citrazinic acid (method C) to form colored azo-dyes, exhibiting absorption maxima ( max) at 400, 550, and 460 nm, for methods A, B, and C, respectively. The produced colored azo-dyes are stable for more than 2 h. Beer's law was obeyed in the concentration range of 0.5-20, 0.3-14 and 0.5-12 g/mL for methods A, B, and C, respectively and the corresponding molar absorptivity values are 1.01 � 10 4, 1.00 � 10 4, and 1.51 � 10 4 L mol-1cm-1. All variables have been optimized and the results were statistically compared with those of a literature method by employing the Student's t-test and F-test. No interference was observed from common adjuvants normally added to the tablets. The results obtained in the proposed methods are in good agreement with labeled amounts, when marketed pharmaceutical preparations are analyzed, which could be applied in the routine quality control analysis laboratory

Development and validation of indirect visible spectrophotometric methods for oxcarbazepine in pure and the tablet dosage form

Three simple, accurate and highly sensitive indirect spectrophotometric methods have been developed for the determination of oxcarbazepine (OXC) in both pure and in pharmaceutical preparations. The methods are based on the oxidation of oxcarbazepine by a known excess of cerium(IV) in acid medium. This was followed by the determination of unreacted cerium(IV), which oxidizes leuco dyes to colored dyes in the same acid medium. In method A, an unreacted cerium(IV) oxidizes leuco crystal violet to crystal violet dye which is measured at 580nm. A bluish-colored malachite green with a maximum absorption at 610nm is developed in method B. In method C, cerium(IV) oxidizes leuco xylene cyanol FF to blue colored xylene cyanol FF having absorption maximum at 610nm. In all these methods, the amount of cerium(IV) reacted corresponds to the amount of OXC and the absorbance is found to decrease linearly with OXC concentration. Beer’s law was obeyed in the concentration range of 0–2.5, 0–2.0 and 0–2.5μgml−1 for methods A, B and C, respectively, and the corresponding molar absorptivity values are 3.86×104, 4.41×104 and 2.16×104lmol−1cm−1. All variables have been optimized and the results were statistically compared with those of a literature method by employing the student’s t-test and F-test. No interference was observed from excipients normally added to the tablets

Development and validation of indirect visible spectrophotometric methods for oxcarbazepine in pure and the tablet dosage form

Three simple, accurate and highly sensitive indirect spectrophotometric methods have been developed for the determination of oxcarbazepine (OXC) in both pure and in pharmaceutical preparations. The methods are based on the oxidation of oxcarbazepine by a known excess of cerium(IV) in acid medium. This was followed by the determination of unreacted cerium(IV), which oxidizes leuco dyes to colored dyes in the same acid medium. In method A, an unreacted cerium(IV) oxidizes leuco crystal violet to crystal violet dye which is measured at 580nm. A bluish-colored malachite green with a maximum absorption at 610nm is developed in method B. In method C, cerium(IV) oxidizes leuco xylene cyanol FF to blue colored xylene cyanol FF having absorption maximum at 610nm. In all these methods, the amount of cerium(IV) reacted corresponds to the amount of OXC and the absorbance is found to decrease linearly with OXC concentration. Beer’s law was obeyed in the concentration range of 0–2.5, 0–2.0 and 0–2.5μgml−1 for methods A, B and C, respectively, and the corresponding molar absorptivity values are 3.86×104, 4.41×104 and 2.16×104lmol−1cm−1. All variables have been optimized and the results were statistically compared with those of a literature method by employing the student’s t-test and F-test. No interference was observed from excipients normally added to the tablets

Spectrophotometric determination of valsartan using p-chloranilic Acid as π-acceptor in pure and in Dosage forms

The aim of this work was to develop a simple, sensitive and extraction free spectrophotometric method for the quantitative estimation of valsartan in both pure and in pharmaceutical preparations. The developed method is based on the charge transfer complexation reaction between valsartan (VRT) as n- electron donor and p-chloranilic acid (p-CA) as π-acceptor. VRT reacts with p-CA in methanol to produce a bright pink colored complex with a maximum absorption at 530 nm. Beer's law was obeyed in the concentration range of 5-50 µg/mL. The linear regression equation of the calibration graph is A = 0.0081+0.0092C with a regression coefficient (r) of 0.9976 (n = 7). The molar absorptivity is calculated to be 2.06 × 103 L mol-1 cm-1and the Sandell sensitivity is 0.1025 μg cm-2 The limits of detection (LOD) and quantitation (LOQ) values are calculated according to ICH guidelines. The method developed is successfully applied to the determination of VRT in dosage forms

Antidepressant drugs: Highly sensitive and validated spectrophotometric technique

A simple, rapid, selective and highly sensitive spectrophotometric method is described for the quantitative determination of the tricyclic antidepressant drugs, desipramine hydrochloride (DPH), clomipramine hydrochloride (CPH) and imipramine hydrochloride (IMH) in pure and in pharmaceutical preparations. The proposed method is based on the bromination of above drugs with known excess of bromine. The unreacted bromine is determined based on its ability to bleach the dye Eiochrome blue black R quantitatively at 530 nm for all the three drugs obeying Beer’s law in the range, 0.0 – 8, 0.0 – 10 and 0.0 – 9.0 µg ml-1 for DPH, CPH and IMH, respectively. The molar absorptivity values were found to be 1.61 × 104 , 1.62 × 104 and1.57 × 104 l mol-1cm-1, respectively with the corresponding Sandell’s sensitivity values 0.0187, 0.0216 and 0.0202 µg cm-2. The limits of detection and (LOD) and quantification (LOQ) are also reported for the developed method. Intra- and inter-day precision and accuracy of the method were established according to the current ICH guidelines. Applications of the procedure to the analysis of various pharmaceutical preparations gave reproducible and accurate results. Further, the validity of the procedure was confirmed by applying the standard addition technique and the results were evaluated in terms of Student’s t-test and variance ratio F-test to find out the significance of proposed method over the reference metho

Simple and extraction-free spectrophotometric methods for risperidone in pure form and in dosage forms

Two simple, sensitive and extraction-free spectrophotometric methods are described for the estimation of risperidone (RSP) in both pure and in pharmaceutical preparations. The proposed methods are based on the formation of ion-pair complex between RSP and the dyes bromophenol blue (BPB) in method A and phenol red (PR) in method B, at room temperature, to form yellow colored products which show maximum absorbance at 410 and at 400 nm in methods A and B, respectively. Beer's law was obeyed in the concentration range of 0.5-10 and 0.5-25 μg mL-1 in methods A and B with apparent molar absorptivities of 3.44�104 and 0.85�104 L moL-1 cm-1, respectively. The limit of detection for method A is found to be 0.0056 and for method B is 0.132 μg mL-1. The composition of the ion-pairs was established by Job's method and it was found to be 1:1 for both the methods A and B. The proposed methods have been applied successfully to the determination of RSP in pharmaceutical preparations. The results were statistically compared with those of a reference method by applying the Student's t-test and F-test. The methods developed were validated for accuracy and precision by performing recovery experiments via standard addition technique