Development of Orodispersible Tablets of Candesartan Cilexetil- β -cyclodextrin Complex

Choc-Tadalafil Fusion: Unlocking Solubility and Taste Harmony with β-CD-Infused Medicated Chocolate

OBJECTIVE

The primary limitations of tadalafil in treating erectile dysfunction are its low solubility and unpleasant bitter taste, which ultimately result in inadequate patient adherence. The present study aimed to develop and characterize a medicated chocolate formulation containing Tadalafil and β-CD (solubility enhancer) employing the concept of Design of Experiment (DoE) using chocolate as a user-friendly excipient.

METHODS

An inclusion complex was formulated by incorporating the drug into β-CD using the kneading method for solubility improvement and also as a taste masker for Tadalafil. The ratio of drug: β-CD inclusion complex was selected based on a phase solubility study. The inclusion complex was molded into a chocolate base and optimized using the DoE approach. Further, drug excipient interaction was evaluated by DSC and FTIR study.

RESULTS

Phase solubility study suggested a 1:1 ratio of Tadalafil: β-CD for better solubility. DSC spectra suggested the conversion of crystalline structure into an amorphous state which indicates improvement of the drug solubility. DSC and FTIR studies revealed that there was no significant interaction between drug and excipients. Next, %CDR (cumulative drug release) at 30 min revealed the immediate effect of Tadalafil from chocolate formulation and free drug analysis (an unbound drug with β-CD) proved reduced bitterness of the drug in the complex. Additionally, the medicated chocolate was found to be stable at room temperature as per stability study.

CONCLUSION

β-CD was found to be a promising multifunctional excipient as a solubility enhancement carrier and taste masker for bitter-tasting drugs.

Solusomes (novel soluplus® enriched nano-vesicular carriers) for improving the oral bioavailability of Candesartan cilexetil

Candesartan cilexetil (CAN) is administered for treating hypertension and heart failure. CAN suffers poor oral bioavailability, owing to limited aqueous solubility, and first-pass metabolism. Solusomes (novel Soluplus® enriched nano-vesicular carriers) combine the merits of Soluplus®, and the traditional liposomes. They were explored to increase CAN solubility, allow a high drug release rate, and improve the oral drug bioavailability. Solusomes were developed via thin film hydration technique utilizing lipid (phosphatidylcholine; PC) and polymeric solubilizer (Soluplus®; Solu). S6 system comprising PC (0.1% w/v), CAN and Soluplus® (at 1:5 ratio; w/w), following a 5 min sonication period, was the optimum one with respect to drug entrapment efficiency (83.5 ± 2.6%), drug loading (11.9 ± 0.3%), particle size and shape (377.2 ± 12.1 nm, spherical), zeta-potential (-19.6 ± 2.1 mV), saturated drug solubility (32.09 ± 0.71 µg/mL), drug released % after 1 h (68 ± 0.9%), and stability. Significantly higher Cmax (969.12 ± 46.3 ng/mL), shorter median Tmax (1h), and improved relative bioavailability (≈ 6.8 folds) in rabbits could evidence the potential of S6 system in enhancing oral CAN bioavailability. S6 solusomes act as dual platform to improve the oral drug bioavailability and maintain effective drug concentration for a prolonged period.

Inclusion Complex of Ibuprofen-β-Cyclodextrin Incorporated in Gel for Mucosal Delivery: Optimization Using an Experimental Design

β-Cyclodextrin/ibuprofen inclusion complex was synthesized by freeze-drying method and characterized for phase solubility profiles, infrared spectra, thermal analysis, and X-ray powder diffractograms. The inclusion complex with HP-β-CD, as confirmed by molecular dynamics simulations, enhanced the aqueous solubility of ibuprofen by almost 30-fold compared to ibuprofen alone. Different grades of Carbopol (Carbopol 934P/Carbopol 974P/Carbopol 980 NF/Carbopol Ultrez 10 NF) and cellulose derivatives (HPMC K100M/HPMC K15M/HPMC K4M/HPMC E15LV/HPC) were evaluated for mucoadhesive gels incorporating the inclusion complex. The central composite design generated by Design-Expert was employed to optimize the mucoadhesive gel using two independent variables (a varying combination of two gelling agents) on three dependent variables (drug content and in vitro drug release at 6 h and 12 h). Except for the methylcellulose-based gels, most of the gels (0.5%, 0.75%, and 1% alone or as a mixture thereof) exhibited an extended-release of ibuprofen, ranging from 40 to 74% over 24 h and followed the Korsmeyer-Peppas kinetics model. Using this test design, 0.95% Carbopol 934P and 0.55% HPC-L formulations were optimized to increase ibuprofen release, enhance mucoadhesion, and be non-irritating in ex vivo chorioallantoic membrane studies. The present study successfully developed a mucoadhesive gel containing the ibuprofen-β-cyclodextrin inclusion complex with sustained release.