Preformulation Studies of Alogliptin as Floating Microspheres for Gastroretentive Drug Delivery

Abstract

Objective: Alogliptin is a selective, orally-bioavailable, pyrimidinedione-based dipeptidyl peptidase-4 (DPP-4) inhibitor with hypoglycemic activity. Designing a new gastroretentive dosage form for alogliptin compels performing preformulation studies for drug. Therefore, the current aim of the study was to investigate some of the important physicochemical properties of alogliptin which can help to select subsequent approaches during the development of floating microspheres for oral use.

Methods: Preformulation studies of drug were carried out for identification (physical appearance, melting point and UV spectrophotometric analysis), solubility profile, lipophilicity (Partition coefficient), compatibility studies by fourier transform infrared (FTIR) spectroscopy and thermal behavior by differential scanning calorimetry (DSC).

Results: The melting point of alogliptin was found to be 187±3^○C. The log P value was found to be 0.46±0.02, from which it can be interpreted that drug is highly hydrophobic in nature. The scanned λ_max were found to be 236 nm. No significant changes were found when FTIR spectra of physical mixture compared with FTIR spectra of pure drug and excipients. This indicates absence of any possible interaction between the drug and excipients which confirms the identity and purity of drug. DSC thermogram of pure drug showed a sharp exothermic peak at 191.923ºC (area=68.890 mJ, delta H=22.963 J/g) indicating the crystal melting point of the drug.

Conclusion: These results suggest that the alogliptin serve as suitable candidate for gastroretentive drug delivery system.