Commercial Dosage Forms Research Articles

Kinetic spectrophotometric method for the determination of perindopril erbumine in pure and commercial dosage forms

A kinetic spectrophotometric method has been developed for the determination of perindopril erbumine in pure and commercial dosage forms. The method is based on the reaction of drug with potassium permanganate in alkaline medium at room temperature (30±1°C). The reaction was followed spectrophotometrically by measuring the increase in absorbance with time at 603nm and the initial rate, fixed time (at 8.0min) and equilibrium time (at 90.0min) methods were adopted for constructing the calibration graphs. All the calibration graphs are linear in the concentration range of 5.0–50.0μg/ml. The limits of detection for initial rate, fixed time and equilibrium time methods were 0.752, 0.882 and 1.091μg/ml, respectively. The activation parameters such as Ea, ΔH‡, ΔS‡ and ΔG‡ were also determined for the reaction and found to be 60.93kJ/mol, 56.45kJ/mol, 74.16J/Kmol and −6.53kJ/mol, respectively. The variables were optimized and the proposed methods are validated as per ICH guidelines. The method has been further applied to the determination of perindopril erbumine in commercial dosage forms. The analytical results of the proposed methods when compared with those of the reference method show no significant difference in accuracy and precision and have acceptable bias.

Kinetic Spectrophotometric Methods for the Determination of Chloramphenicol in Pharmaceutical Preparations

Simple and sensitive kinetic methods are described for the determination of chloramphenicol in pure form and pharmaceutical preparations. The methods are based on oxidative – coupling reaction between reduced chloramphenicol (by zinc powder and concentrated hydrochloric acid) with promethazine hydrochloride in the presence of sodium periodate yielding a highly colored product at room temperature, the reaction is followed spectrophotometriclly at λmax= 590 nm. Initial rate and fixed time (at 20 minutes) methods are utilized for concentration determination. The calibration graphs were linear in the concentration ranges (2-20 µg.ml -1 ) and (0.5-30 µg.ml -1 ) respectively. The results were validated statistically and checked through recovery studies, and have been applied successfully for the determination of chloramphenicol in commercial dosage forms.

METHOD DEVELOPMENT AND VALIDATION FOR THE ESTIMATION OF ROPINIROLE HCL IN TABLETS BY RP-HPLC

A simple and precise and accurate RP - High-performance liquid chromatography (Reverse Phase - HPLC) method has been developed for the estimation of Ropinirole in tablet formulations. The separation was achieved on a C18(250 x 4.6 mm) 5 - micron Hypersil BDS using a mobile phase consisting of a degassed mixture of 0.05 M glacial acetic acid (2.85 mL of glacial acetic acid in 1000 mL of water) and acetonitrile (50:50) with a flow rate of 1.0 mL/min. The mobile phase showed the most favorable chromatographic parameter for analysis. The detection of the constituent was done using UV detector at 250 nm. The retention time of ropinirole was found to be 3.987 minutes. The method was validated for system suitability, precision, accuracy, linearity, robustness. The linear range for ropinirole was 4 12 g / ml. The method is validated for accuracy, precision, linearity, specificity and robustness in accordance with ICH guidelines and revealed that the method established specific, accurate, rapid, precise, reliable and reproducible for the method has been successfully used to analyze commercial solid dosage forms which are locally available 0.25 mg ropinirole tablets and its percentage recovery was found to be 99.82%.

Spectrofluorimetric determination of certain biologically active phenothiazines in commercial dosage forms and human plasma

A validated simple and sensitive spectrofluorimetric method was developed for the determination of chlorpromazine hydrochloride, promethazine hydrochloride, trifluperazine hydrochloride, thioridazine hydrochloride, perazine maleate and oxomemazine. The method was based on condensation of malonic acid/acetic anhydride (MAA) under the catalytic effect of the tertiary amine moiety of the studied phenothiazines to provide a deep yellow to brown colour with green fluorescence. Relative fluorescence intensity of the products was measured at λ exc 398 nm and λ em 432 nm. Different variables affecting the reaction were studied and optimized. The method was successfully applied for the determination of the studied drugs in commercial dosage forms. The lower detection limits allowed the application of this method for the determination of the compounds in plasma as an example of a biological fluid. In addition, the method was considered specific for the determination of tertiary amines in the presence of primary and secondary amines; as a result, it was deemed suitable for the determination of the cited drugs in the presence of their degradation products resulting from N-dealkylation or oxidation of the corresponding sulphoxides or sulphones.

Diagnostic handling of the preparation of epicutaneous patch tests requested by the Allergology Department

BackgroundIn epicutaneous patch testing, the substance suspected of being responsible for the skin reaction (contact dermatitis and/or delayed drug reaction) is applied (in excipient) on the skin under occlusion to...

Spectrofluorimetric determination of doxepin hydrochloride in commercial dosage forms via ion pair complexation with alizarin red S

A simple and sensitive spectrofluorimetric method has been developed for the determination of doxepin hydrochloride in pharmaceutical preparations. It is based on the formation of ion-pair complex between doxepin and alizarin red S at pH 3.09. The ion pair complex was extracted in dichloromethane and the fluorescence intensity was measured at 560nm after excitation at 490nm. The optimum conditions for determination were also investigated. The linear range and detection limit were found to be 2–14 and 0.55μg/ml, respectively. The method has been successfully applied for the analysis of drug in commercial dosage forms. No interference was observed from common pharmaceutical adjuvant. Statistical comparison of the results obtained by the proposed method with that of the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

Kinetic spectrophotometric determination of β-adrenergic antagonists using alkaline potassium permanganate

A new simple and sensitive kinetic spectrophotometric method is described for analysis of bisoprololfumarate (BSF) and propranolol hydrochloride (PRH) in pure and pharmaceutical formulations. The method involves the reaction of the drugs with alkaline potassium permanganate producing bluish-green manganate species. The reaction was followed spectrophotometrically by measuring the increase in the absorbance from the formation of MnO4 2- at 610 nm. The different experimental parameters affecting the development and stability of the colors were carefully studied and optimized. The fixed-time method is adopted for constructing the calibration curves, which were found to be linear over the concentration ranges of 2.0-16g/mL for BSF and 2.0-18g/mL for PRH. The determination of the studied drugs by initial rate, variable time and rate-constant methods was feasible with the calibration equations obtained but the fixed time method has been found to be more applicable. The method has been successfully applied for the determination of drugs in commercial dosage forms. The results were validated through inter-day and intra-day precision assays according to the ICH guidelines and also through recovery studies. Statistical comparison of the proposed method with that of official methods shows excellent agreement and indicates no significant difference in their accuracy and precision.

N-octyl-O-sulfate chitosan-modified liposomes for delivery of docetaxel: Preparation, characterization, and pharmacokinetics

A N-octyl-O-sulfate chitosan (NOSC) anchored liposome system was developed as the carrier for antitumor drug, docetaxel (DTX). The physicochemical and pharmacokinetic properties of NOSC-modified DTX liposomes (NDLs) were evaluated compared with the conventional DTX liposomes (DLs) and commercial dosage form of DTX, Taxotere®. The results showed that NDLs had DTX-loading rate of 3.41%, entrapment efficiency of 61.73%, narrow distributed particle size of 147.6±1.9nm, and high zata potential of −44.2±3.9mV. The decreased permeability of the liposome bilayer was evaluated by release behavior of calcein (CAL) from the internal phase of NOSC-modified CAL liposomes (NCLs) and enhanced stability of NDLs owed to shielding effect of sulfonic shell from adsorption by BSA. After i.v. administration at the dose of 12mg/kg, a significant increase in the AUC, MRT, and T1/2β (P<0.05) was observed in NDLs group compared with DLs and Taxotere® group. AUC0–∞ of NDLs was 6.14 and 1.55 times higher than Taxotere® and DLs, respectively, and MRT0–∞ of NDLs was 5.77 and 1.37 times higher than Taxotere® and DLs, respectively. All these results suggested that anchored liposomes could increase the stability of DTX in vitro and in vivo, as compared with conventional liposomes and Taxotere®. Therefore, NOSC as a polymeric shell to liposomes was effective to enhance the stability of liposomes containing DTX.

Indirect spectrophotometric method for the determination of bisacodyl in commercial dosage forms and in environmental water samples

Objective: A simple, sensitive, and accurate indirect spectrophotometric method for the determination of bisacodyl in pure form and in some of its pharmaceutical preparations. Method: The method is based on the oxidation of bisacodyl by iron (III), and subsequent complexation of iron (II) with o-phenanthroline. Results: Forming a red-colored complex (ferroin) having the maximum absorbance at 510 nm. Beer’s law is obeyed in the concentration range of 0.5-5 µg/ml. The molar absorptivity and sandell’s sensitivity were 1.55×10 4 L.mol -1 .cm -1 and 0.0233µg.cm -2 respectively. The relative standard deviation (RSD) was less than 1.5 (n=11). The limits of detection and quantitation are 0.083 and 0.25 µg.ml -1 respectively. Conclusion: The method is applied successfully for determination of bisacodyl in environmental water samples and in some pharmaceutical formulations (tablets and suppositories). A statistical comparison of these results with those of official method shows good agreement and indicates no significant difference in the precision.

Spectrophotometric Determination of Zidovudine in Pharmaceutical Dosage Forms

A simple, sensitive and economical spectrophotometric method has been developed for the determination of zidovudine in commercial dosage forms. The method was based on the formation of chloroform extractable complex of zidovudine with wool fast blue. The absorbance of the extractable ion pair complex is measured at the wavelength of maximum absorbance 590 nm against the reagent blank treated similarly. Statistical analysis proves that the proposed methods are reproducible and selective for the estimation of zidovudine in bulk drug and in its tablet dosage form.

Simultaneous Determination of Norfloxacin and Tinidazole Binary Mixture by Difference Spectroscopy

A simple and rapid difference spectroscopic method was developed for the simultaneous determination of binary mixture of norfloxacin (NF) and tinidazole (TZ) without prior separation. The proposed method depends upon measuring the absorbance of NF at 291.6 nm which is the zero crossing point on the difference spectra of TZ in 0.1 N NaOH vs. 0.1 N HCl. Similarly, the absorbance of TZ was measured at 344.4 nm which is the zero crossing point on the difference spectra of NF. Beer's law was obeyed in the concentration range of 2-20 and 5-50 µg/mL for NF and TZ, respectively. The lower limits of detection (LOD) of NF and TZ are 0.23 and 0.36 µg/mL, respectively, while the lower limits of quantification (LOQ) of NF and TZ were 0.70 and 1.08 µg/mL, respectively. The precision of the method was satisfactory; the maximum value of relative standard deviations did not exceed 1.5% (n=10). The accuracy, expressed as recovery is between 98.25 and 101.8% with relative error of 0.29 and 0.23 for NF and TZ, respectively. The proposed method was successfully applied for the determination of both drugs in bulk powder, laboratory prepared mixture and commercial dosage forms such as tablets without interference from the commonly encountered excipients and additives. The results obtained are in good agreement with those obtained by the reference methods.

Spectrofluorimetric determination of two β-agonist drugs in bulk and pharmaceutical dosage forms via derivatization with dansyl chloride

A sensitive, simple and rapid spectrofluorimetric method has been developed for the determination of both Fenoterol hydrobromide (FNT) and Ritodrine hydrochloride (RTH) in pure and dosage forms. The method is based on derivatization using dansyl chloride (DNS-Cl) as fluorogenic agent and measuring the fluorescence of the products at emission wavelengths of 517 and 515 nm after excitation at 348 and 343 nm for FNT and RTH, respectively. Different experimental parameters affecting the fluorescence intensities were carefully studied and optimized. The relation between fluorescence intensities and drug concentrations were rectilinear over the concentration range of 0.25–6.0 μg/mL for both drugs with a minimum detectability of 0.065 and 0.045 μg/mL for FNT and RTH, respectively. The percentage recoveries ±SD were 100.1 ± 0.9, 99.9 ± 0.6 for FNT and RTH respectively. The proposed method was successfully applied to the determination of both drugs in their commercial dosage forms. The obtained results were statistically validated and agreed well with those obtained with reference methods. A suggestion for the reaction pathway with DNS-Cl was postulated.

In vitro properties of surface—modified solid lipid microspheres containing an antimalarial drug: halofantrine

Objective To formulate and evaluate in vitro, surface-modified solid lipid microspheres containing halofantrine using lipid matrix formed from goat fat and a phospholipid (P90H). Methods The model drug, halofantrine in an increasing concentration of 1%, 2%, 3%, 4% and 5% w/w was incorporated into surface-modified solid lipid microspheres formulated by hot homogenization. Effect of drug concentration on the encapsulation efficiency was studied. The dispersion was evaluated using particle size, particle morphology, pH and encapsulation efficiency. The drug formulation with highest encapsulation efficiency was selected and used for the release studies and compared with the release from a commercial dosage form (Halfan® 250 mg tablet, Glaxo-Smithkline, Mayenne France) using simulated gastric fluid (SGF pH 1.2), simulated intestinal fluid (SIF pH 7.2) and phosphate buffer (pH 6.8) as biorelevant media. Results were analyzed statistically and the level of significance was taken to be P < 0.05). Results Discrete and spherical solid lipid microspheres were produced. The particle size of the dispersion was low (32.48–33.87 μm) with minimal particle growth and high encapsulation efficiencies (86.8%–91.0%) after 3 months. The pH of the microspheres dispersion changed appreciably after 3 months. In vitro release result obtained revealed sustained and controlled drug release from the lipid microspheres compared with the tablet dosage form. Conclusions Formulation of halofantrine as solid lipid microspheres presents a better alternative to the conventional tablet formulation as the in vitro dissolution of the highly lipophilic halofantrine was highly improved.

A simple kinetic spectrophotometric method for determination of Tizanidine hydrochloride in pharmaceutical preparations

A simple, reliable, and sensitive kinetic method for the accurate and sensitive determination of Tizanidine hydrochloride (TIZ) is described. The method is based on the alkaline oxidation of TIZ with potassium permanganate at a fixed time of 25min. The formed manganate ion is measured at 610nm. The concentration of TIZ is calculated using the calibration equation for the fixed time method. Beer’s law is obeyed in the range of 2–13μgml−1, and the results are validated statistically and checked through recovery studies. This method has been successfully applied for the determination of the studied drug in commercial dosage forms. Statistical comparisons of the results with the reference methods show excellent agreement and indicate no significant difference in accuracy and precision.

Simultaneous determination of ampicillin sodium and sulbactam sodium in binary mixtures and commercial dosage forms using chemometrics - assisted spectrophotometric techniques

Simultaneous determination of ampicillin sodium and sulbactam sodium in binary mixtures and commercial dosage forms using chemometrics - assisted spectrophotometric techniques

Validated RP-HPLC Method for the Determination of Zolmitriptan - A Serotonin 5-HT Receptor Agonist

A simple precise, accurate RP-HPLC method has been developed and validated for analysis of Zolmitriptan (ZLM). The separation and quantization were achieved on a 250 mm reversed phase column with a hydrophilic linkage between silica particles and hydrophobic alkyl chains. The mobile phase was constituted (flow rate 0.8 ml min-1) of eluant A (CH3OH) and eluant B (aqueous tetra butyl ammonium hydrogen sulphate) (pH 3.4; 10 mM) using isocratic elution with UV detection at 224 nm. The method showed good linearity for ZMT in the 1–100 μg mL-1 range with regression equation 15576x ± 99401 and correlation coefficient 0.999 respectively. The limit of quantitation (LOQ) and limit of detection (LOD) were found to be 0.8134 and 0.2687 μg mL-1 respectively. Finally the applicability of the method was validated according to ICH guidelines and can be applicable for the analysis of commercial dosage forms.

Spectrophotometric determination of penicillins in pure and pharmaceutical formulations using Folin‐Ciocalteu reagent

A new combination of time, temperature, and alkali is described for the spectrophotometric determination of amoxicillin and ampicillin using Folin-Ciocalteu reagent. The method is based on the development of blue-coloured product due to the reduction of tungstate and/or molybdate in Folin-Ciocalteu reagent by amoxicillin and ampicillin in alkaline medium. The chromogenic reaction has λ(max) at 720 and 740 nm with molar absorptivity 1.6295 × 10⁴ and 0.1085 × 10⁴ l mol⁻¹ cm⁻¹ in the Beer's Law range 2-10 µg mL⁻¹ and 10-70 µg mL⁻¹ for amoxicillin and ampicillin, respectively. The method is reproducible, quick, inexpensive, and particularly helpful in determining the drug content in commercial dosage forms.

Development and validation of rapid HPLC method for determination of doxofylline in bulk drug and pharmaceutical dosage forms

A simple, selective, rapid, and economical reversed phase high performance liquid chromatography(RP-HPLC) method for the determination of doxofylline in the commercial dosage form has been developed and validated. The separation and quantification were achieved on an HiQ Sil C 18 W column using a mobile phase of acetonitrile: buffer (50: 50), pH 3, at a flow rate of 1 mL/min with detection of analyte at 272 nm. The separation was achieved within 3.1 ± 0.3 min for doxofylline sample. The method showed good linearity in the range of 10–80 μg/mL. The intra and inter day RSD ranged from 0.37–0.53%. The recovery (mean ± S.D.) of low, middle and high concentrations were 100.04 ± 0.80, 100.01 ± 0.20, 100.07 ± 0.30 respectively. Limit of detection and limit of quantification were 0.03 and 0.1 μg/mL, respectively.

Microemulsion formulation of clonixic acid: solubility enhancement and pain reduction.

Clonixic acid is currently marketed as a salt form because of its poor water-solubility. However, the commercial dosage form causes severe pain after intramuscular or intravenous injection. To improve the solubility of clonixic acid and to reduce pain on injection, clonixic acid was incorporated into oil-in-water microemulsions prepared from pre-microemulsion concentrate composed of varying ratios of oil and surfactant mixture. As an oil phase for drug incorporation, up to 14% castor oil could be included in the pre-microemulsion concentrate without a significant increase in droplet size. Both drug contents and droplet size increased as the weight ratio of Tween 20 to Tween 85 decreased. Taken together, when microemulsions were prepared from pre-microemulsion concentrate composed of 5:12:18 weight ratio of castor oil:Tween 20:Tween 85, clonixic acid could be incorporated at 3.2 mg mL(-1) in the microemulsion with a droplet size of less than 120 nm. The osmotic pressure of this microemulsion was remarkably lower than the commercial formulation, irrespective of the dilution ratios. The rat paw-lick test was used to compare pain responses among formulations. The microemulsion formulation significantly reduced the number of rats licking their paws as well as the total licking time, suggesting less pain induction by the microemulsion formulation. The pharmacokinetic parameters of clonixic acid after intravenous administration of the clonixic acid microemulsion to rats were not significantly different from those of the commercial formulation, lysine clonixinate. The present study suggests that microemulsion is an alternative formulation for clonixic acid with improved characteristics.

ANALYSIS OF PARACETAMOL AND ASCORBIC ACID IN PHARMACEUTICAL BINARY MIXTURE

Two simple and sensitive spectrophotometric methods were developed for the determination of paracetamol (I) and ascorbic acid (II) in pharmaceutical binary mixture. The first method depends on the use of the first-derivative spectrophotometric technique for the simultaneous determination of components of the mixture. The second method depends on the reaction of the studied drugs with 5-diazo-1, 2, 4-triazol-3-carboxylic acid (DTCA) reagent to give colored products measured at 480 nm and 380 nm for (I) and (II), respectively. All variables affecting reaction conditions were optimized. The proposed methods were successfully applied for the analysis of the studied drugs in their pure and commercial dosage forms and are in good agreement with those obtained from the reported methods. No significant difference in the accuracy and precision as revealed by the accepted values of t- and F-tests, respectively. Molar ratios of the drugs with the colorimetric reagent (DTCA) were determined and the reaction mechanisms were suggested.