Development and characterization of ceftriaxone in-situ gel-forming biodegradable parenteral depot system

Purpose: To design parenteral in-situ gel of ceftriaxone using poloxamer as a thermosensitive agent, Carbopol as a pH-sensitive polymer and hydroxypropyl methylcellulose as a viscosity enhancer. Method: Lyophilized ceftriaxone was added in solution form to enhance its solubility and stability. Several formulations were designed using poloxamer (P 188, F 127 and P 407) and Carbopol (934P and 940) in varying concentrations, out of which an optimized formulation was chosen on the basis of its gelling capacity and respective transit time. Drug content uniformity, sterility and stability were studied. Drug-polymer and polymer-polymer interaction were determined by differential scanning calorimetry (DSC). Characterization of optimized formulation was carried out by Fourier transform infrared spectroscopy (FTIR). In-vitro release profile was determined by a modified Franz diffusion method. Results: Optimized formulation Q2 was characterized for various physicochemical parameters and found to be stable. In-vitro release study showed first order release pattern. DSC thermograms revealed that the polymers were compatible with each other as no physicochemical interactions were observed. The results were expressed as mean ± standard deviation (SD, p ≤ 0.05). Conclusion: Optimized formulation Q2 provided sustained release up to 10 days following first order release kinetics, and thus can be further developed for large-scale production