An accurate, sensitive, precise, rapid, isocratic reversed phase HPLC (RP-HPLC) method for the determination of doxycycline hyclate in bulk drug and in tablets, and also in spiked human urine, was developed and validated The best separation was achieved on a 250 mm × 40 mm id, 50 µm particle size C 8 reversed phase thermo column with acetonitrile-potassium dihydrogenorthophosphate buffer (pH 40), 40:60 (v/v) as mobile phase at a flow rate of 10 mL/min UV detection was performed at 325 nm at ambient column temperature (25 °C) The method was linear over the concentration range of 30-300 µg/ mL (r=09994) with limits of detection and quantification of 002 and 01 µg/ mL, respectively The drug was subjected to oxidation, acid and base hydrolysis, photolysis and heat as stress conditions Degradation products were found interfering with the assay of doxycycline hyclate only in oxidation and base hydrolysis, therefore the method can be regarded as indicating stability in the case of acid hydrolysis, photolysis and heat stress conditions The method was applied for determination of doxycycline hyclate in pharmaceuticals and spiked human urine with excellent recoveries The method can be used for the quality control of doxycycline hyclate

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Development and validation of RP-HPLC method for the determination of doxycycline hyclate in spiked human urine and pharmaceuticals

A spectrophotometric method for the determination of doxycycline (DOX) is described. The method is based on the formation of blue colored chromogen due to reduction of tungstate and/or molybdate in Folin-Ciocalteu (F-C) reagent by DOX in alkaline medium. The colored species has an absorption maximum at 770 nm and the system obeys Beer’s law over the concentration range 0.75–12.0 m gm L –1 DOX. The apparent molar absorptivity is 2.78 ´ 10 4 L mol –1 cm –1 . The limit of quantification and detection values are reported to be 0.20 and 0.08 mg mL –1 , respectively. Over the linear range applicable, the accuracy and precision of the method were evaluated on intra-day and inter-day basis. The reported mean accuracy value was 101.0 ± 1.7 %, the relative error was 2.7 % and the relative standard deviation was 2.5 %. Application of the proposed method to bulk powder and commercial pharmaceutical tablets is also presented. No significant difference was obtained between the results of the proposed method and the official BP method. The procedure described in this paper is simple, rapid, accurate and precise.

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Sensitive and selective spectrophotometric assay of doxycycline hyclate in pharmaceuticals using Folin-Ciocalteu reagent

New, rapid and sensitive spectrophotometric methods have been developed for the determination of Oxytetracycline (OTC) and Hostacycline (HTC). The procedure is based on the observation that, OTC or HTC forms colored complexes with Zirconium (IV), the absorbance of which is proportional to the amount of tetracycline present. The variables affecting development of the color have been investigated and the conditions are optimized. Beer’s law is obeyed in the range 1.0-33.5 μg/ml for OTC and 4.0-40.0 μg/ml for HTC. The proposed methods can be employed for the analytical determination of Zirconium (IV). The corresponding Beer’s law ranges are 0.2-6.1 μg/ml with OTC and 0.5-7.3 μg/ml with HTC. Stoicheiometry of the complexes, regression parameters and relative standard deviation are reported for each of these determinations. The methods are successfully applied for the determination of OTC and HTC in pharmaceutical formulations and urine. Key words: Spectrophotometric determination, oxytetracycline,
hostacycline, zirconium (IV).

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Spectrophotometric methods for the microdetermination of Oxytetracycline and Hostacycline.

A simple, efficient, precise and accurate Vierodt's method have been developed for the estimation of Diazepam and Propranolal in pure and in fixed dose Combination. In this method UV spectrum of Diazepam and Propranolal were overlained which involves the formation of Simultaneous equation at maximum wavelength 241 nm and 289 nm. Both the drugs obeyed Beer's law in the concentration range 2–25 μg/ml and 1–45 μg/ml for Diazepam and Propranolal, respectively. The accuracy of the method was determined by recovery studies and was found to be 100.14±0.219% and 100.17±0.134% for Diazepam and Propranolal, respectively. The method was validated as per ICH guidelines. The method was found to be simple, economic, accurate and reproducible and can be used for routine analysis of Diazepam and Propranolal in pure and in fixed dose combination.

Development and Validation of UV Spectrophotometric Method for Simultaneous Estimation of Diazepam and Propranolol in Bulk Drug and Its Formulations

The authors present simple and rapid method for the first derivative spectrophotometric determination of demeclocycline (DMC) and minocycline (MNC). The linear calibration function is established in the concentration range 10 to 50 μg/ml for DMC and 10 to 60 μg/ml for MNC. The proposed method is also applied for their resolution in synthetic binary mixtures. The resolution is based on the first derivative ultraviolet spectrophotometry with zero crossing measurement. The corresponding calibration function is linear in the rage 10 to 40 μg/ml for DMC and 10 to 50 μg/ml for MNC. The proposed methods are found to be selective, linear (R > 0.99), accurate (recovery = 98 to 104%) and precise (RSD < 1.1%) in the respective linear concentration ranges. The method is successfully applied for the analysis of these drugs in clinical samples, urine and honey without pretreatment. Keywords: Demeclocycline; Minocycline; First derivative; Resolution; Applications. DOI: 10.3126/sw.v8i8.3843 Scientific World Vol.8(8) 2010 pp.34-38

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First derivative spectrophotometric determination of demeclocycline and minocycline in clinical samples, urine and honey

A rapid, simple and sensitive method for the spectrophotometric determination of Hostacycline and Doxycycline is developed. The method is based on a fast colour reaction between these drugs and thorium (IV). This method has been successfully applied for determination of the metal as well as the drugs in pharmaceutical formula

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Y Siva Ch

Papers

Determination Of Hostacycline And Doxycycline Using Thorium (IV) As Spectrophotometric Reagent