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

Abstract

Doxycycline hyclate (DOX), chemically known as (4S,4aR,5S,5aR,6R,12aS)-4-(dimethylamino)-3,5,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide hydrochloride hemiethanol hemihydrate (Fig. 1), is one of the tetracycline derivatives, which has a wide range of antibacterial activities. DOX is frequently used to treat chronic prostatitis, sinusitis, syphilis, chlamydia, pelvic inflammatory disease, acne, rosacea, and rickettsial infections.The drug is official in British Pharmacopoeia (1), which describes the HPLC method for the determination of DOX either in raw material or in pharmaceutical formulations. 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 mg mL -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.

A novel fluorescent sensor based on sulfur and nitrogen co-doped carbon dots with excellent stability for selective detection of doxycycline in raw milk

“…Doxycycline (Dox), a tetracycline (Tet) antibiotic, is extensively used to treat many infections, such as chronic prostatitis, respiratory tract infections, sinusitis, and sexually transmitted diseases. 1,2 Dox is also applied in agriculture, forestry, animal husbandry, and aquaculture as a fertilizer or animal food supplement because of its extensive antibacterial ability. 3 However, Dox overuse may lead to serious environmental and food contamination, resulting in considerable risk to human health.…”

A rapid and sensitive assay for determination of doxycycline using thioglycolic acid-capped cadmium telluride quantum dots

“…Substantial efforts have been taken to quantify DC with methods such as spectrophotometry [6][7][8], thin-layer chromatography [9,10], liquid chromatography [11][12][13][14]5], flow injection analysis [15][16][17], capillary electrophoresis [18,19] and electrochemical analysis [20][21][22]. Some of these methods are expensive, time-consuming and require expertise operator; however, fluorescence spectroscopy as a simple, efficient and sensitive method [23,24], has attracted interests for analysis of pharmaceutical compounds such as doxycycline.…”

Utilization of oxidation-reduction reaction of Folin-Ciocalteu’s phenol reagent in colorimetric determination of amlodipine in pharmaceutical dosage form

“…Folin-Ciocalteu's phenol reagent was reported to be used in visible spectrophotometric determination of different drugs. Intense blue color was formed in alkaline medium due to oxidaton-reducion reaction between reagent and drugs [26][27][28][29].…”