Increasing doxycycline hyclate photostability by complexation with β-cyclodextrin.

Area of Science:

• Pharmaceutical Sciences
• Physical Chemistry
• Materials Science

Background:

• Doxycycline hyclate (DOX) is a potent antibiotic with significant photosensitivity.
• Drug photosensitivity limits the stability and shelf-life of pharmaceutical formulations.
• Developing strategies to enhance DOX photostability is crucial for its therapeutic efficacy.

Purpose of the Study:

• To prepare and characterize an inclusion complex of doxycycline hyclate (DOX) with beta-cyclodextrin (βCD).
• To investigate the potential of βCD complexation to improve the photostability of DOX.
• To evaluate the impact of complexation on the drug's integrity and antimicrobial activity.

Main Methods:

• Preparation of DOX-βCD inclusion complex using a freeze-drying method.
• Characterization through nuclear magnetic resonance (NMR), molecular modeling, thermal analysis, and spectroscopic techniques.
• Photostability studies in aqueous solution and antimicrobial assays to assess functional integrity.

Main Results:

• Successful preparation and characterization of the DOX-βCD inclusion complex, with proposed three-dimensional structure.
• Significant reduction in doxycycline hyclate photodegradation observed in the presence of βCD.
• Complexation demonstrated photoprotective effects, maintaining antimicrobial efficacy.

Conclusions:

• Complexation of DOX with βCD is an effective strategy to enhance the drug's photostability.
• The DOX-βCD inclusion complex offers improved stability for pharmaceutical dosage forms.
• This approach presents a promising avenue for developing more stable and effective doxycycline formulations.