OBJECTIVE: This study aims to evaluate the role of maltodextrin, glucose, and mannitol as carriers for in vitro and in vivo performance of Aceclofenac (ACE) proniosomes.
METHODS: Three formulations of proniosomes were prepared by the slurry method using the 100 mg ACE, 500 mg span 60, 250 mg cholesterol with 1300mg of different carriers, i.e., glucose (FN1), maltodextrin (FN2), and mannitol (FN3). In vitro drug release studies were conducted by the USP paddle method, while in vivo studies were performed in albino rats. Pure ACE was used as a reference in all the tests. Lastly, the results were analyzed using the High-Pressure Liquid Chromatography (HPLC) method, and data were evaluated using further kinetic and statistical tools.
RESULTS: No significant differences (p > 0.05) in entrapment efficiency (%EE) of FN1, FN2, and FN3 (82 ± 0.5%, 84 ± 0.66%, and 84 ± 0.34% respectively) were observed and formulations were used for further in vitro and in vivo evaluations. During in vitro drug release studies, the dissolved drug was found to be 42% for the pure drug, while 70%, 17%, and 30% for FN1, FN2, and FN3, respectively, at 15 min. After 24 hrs, the pure drug showed a maximum of 50% release while 94%, 80%, and 79% drug release were observed after 24 hr for FN1, FN2, and FN3, respectively. The in vivo study conducted on albino rats showed a higher Cmax and AUC of FN1 and FN2 in comparison with the pure ACE. Moreover, the relative oral bioavailability of proniosomes with maltodextrin and glucose as carriers compared to the pure drug was 183% and 112%, respectively. Mannitol- based formulation exhibited low bioavailability (53.7%) that may be attributed to its osmotic behavior.
CONCLUSION: These findings confirm that a carrier plays a significant role in determining in vitro and in vivo performance of proniosomes and careful selection of carrier is an important aspect of proniosomes optimization.
OBJECTIVES: Using the pentylenetetrazol (PTZ) discrimination assay, this study aims to investigate the effects of MG in responding to the PTZ stimulus and to assess the generalisation effects of withdrawal from MG to the PTZ stimulus.
METHODS: Rats (n = 20) were trained on a tandem (FR-10, VI-15) schedule of food reinforcement to press one lever after administration of the anxiogenic compound PTZ (16 mg/kg, i.p.) and an alternate lever after vehicle. Following acute tests, training was suspended, and rats were chronically treated with MG or morphine at 8-h intervals for 9 days and withdrawal was precipitated on the tenth day using naloxone (1 mg/kg, i.p.). The rats were tested for generalisation to PTZ at 2, 8 and 24 h after the last dose of MG or morphine administration.
RESULTS: Unlike morphine that produced dose-related PTZ-like stimulus, MG at 3, 10, 30 and 45 mg/kg doses showed no substitution to the PTZ discriminative stimulus. In contrast to morphine which produced a time-dependent generalisation to the PTZ stimulus, naloxone did not precipitate withdrawal effects in MG-treated rats as they selected the vehicle lever at three withdrawal time points.
CONCLUSION: These results demonstrate that MG produces a very different response to morphine withdrawal that is not associated with anxiogenic-like subjective symptoms. These characteristics of MG may provide further support for use as a novel pharmacotherapeutic intervention for managing opioid use disorder.