Doxycycline Hyclate Capsules
» Doxycycline Hyclate Capsules contain the equivalent of not less than 90.0 percent and not more than 120.0 percent of the labeled amount of doxycycline (C22H24N2O8).
Packaging and storage Preserve in tight, light-resistant containers.
USP Reference standards 11
Identification Shake a suitable quantity of Capsule contents with methanol to obtain a solution containing the equivalent of 1 mg of doxycycline per mL, and filter. Using the filtrate as the Test Solution, proceed as directed for Method II under IdentificationTetracyclines 193.
Medium: water; 900 mL.
Apparatus 2: 75 rpm, the distance between the blade and the inside bottom of the flask being maintained at 4.5 ± 0.5 cm during the test.
Time: 30 minutes.
Procedure Determine the amount of C22H24N2O8 dissolved from UV absorbances at the wavelength of maximum absorbance at about 276 nm of filtered portions of the solution under test, suitably diluted with Dissolution Medium, if necessary, in comparison with a Standard solution having a known concentration of USP Doxycycline Hyclate RS in the same medium.
Tolerances Not less than 80% (Q) of the labeled amount of C22H24N2O8 is dissolved in 30 minutes.
Uniformity of dosage units 905: meet the requirements.
Water, Method I 921: not more than 8.5%.
Mobile phase, Diluent, Resolution solution, Standard preparation, and Chromatographic system Proceed as directed in the Assay under Doxycycline Hyclate.
Assay preparation Remove, as completely as possible, the contents of not less than 20 Capsules, and weigh accurately. Mix the combined contents, and transfer an accurately weighed portion of the powder, equivalent to about 100 mg of doxycycline, to a 100-mL volumetric flask, add about 75 mL of Diluent, sonicate for 5 minutes, shake for 15 minutes, dilute with Diluent to volume, and mix. Filter through a membrane filter of 0.5 µm or finer porosity.
Procedure Proceed as directed for Procedure in the Assay under Doxycycline Hyclate. Calculate the quantity, in mg, of doxycycline (C22H24N2O8) in the portion of Capsules taken by the formula:
0.1CP(rU / rS)in which C is the concentration, in mg per mL, of USP Doxycycline Hyclate RS in the Standard preparation, P is the designated potency, in µg of doxycycline per mg, of USP Doxycycline Hyclate RS, and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 2985Pharmacopeial Forum: Volume No. 27(4) Page 2731