Quality-by-Design Based Development of Doxycycline Hyclate-Loaded Polymeric Microspheres for Prolonged Drug Release

This study explores a novel approach to address the challenges of delivering highly water-soluble drug molecules by employing hydrophobic ion-pairing (HIP) complexes within poly (lactic-co-glycolic acid) (PLGA) microspheres. The HIP complex, formed between doxycycline hyclate (DH) and docusate sodium (DS), renders the drug hydrophobic. The development of the microspheres was done using the QbD approach, namely, Box-Behnken Design (BBD). A comprehensive characterization of the HIP complex confirmed the successful conversion of DH. DH and the HIP complex were effectively loaded into PLGA microspheres using the oil-in-water (O/W) emulsion solvent evaporation method. Results demonstrated significant improvements in percentage entrapment efficiency (% EE) and drug loading (% DL) for DH within the HIP complex-loaded PLGA microspheres compared to DH-loaded microspheres alone. Additionally, the initial burst release of DH reduced to 3% within the initial 15 min, followed by sustained drug release over 8 days. The modified HIP complex strategy offers a promising platform for improving the delivery of highly water-soluble small molecules. It provides high % EE, % DL, minimal initial burst release, and sustained release, thus having the potential to enhance patient compliance and drug delivery efficiency.

Distearoyl phosphatidylglycerol and dioleoyl phosphatidylglycerol increase the retention and reduce the toxicity of amphotericin B-loaded in nanoemulsions

Aim: To develop nanoemulsions (NEs) loading amphotericin B (AmB) and to evaluate the influence of different excipients on the stability and the supramolecular organization, retention and toxicity of AmB. Materials & methods: The NEs were developed from different oils, surfactants, external media and anionic lipids (disteaoryl phosphatidylglycerol [DSPG] and dioleoyl phosphatidylglycerol [DOPG]). Their impact on the size, pH, zeta potential, AmB encapsulation efficiency, AmB retention and hemolytic potential of the NEs was evaluated. Results & conclusion: The use of soybean oil (lipid matrix), Span 80 (surfactant), phosphate buffer (external phase) and DSPG or DOPG (hydrophobic ion pair) provided better NE stability, higher AmB retention within the NEs and a safer formulation profile in hemolysis tests.