Lyophilized wafers comprising carrageenan and pluronic acid for buccal drug delivery using model soluble and insoluble drugs

Lyophilized muco-adhesive wafers with optimum drug loading for potential buccal delivery have been developed. A freeze-annealing cycle was used to obtain optimized wafers from aqueous gels containing 2% κ-carrageenan (CAR 911), 4% pluronic acid (F127), 4.4% (w/w) polyethylene glycol with 1.8% (w/w) paracetamol or 0.8% (w/w) ibuprofen. Thermogravimetric analysis showed acceptable water content between 0.9 and 1.5%. Differential scanning calorimetry and X-ray diffraction showed amorphous conversion for both drugs. Texture analysis showed ideal mechanical and mucoadhesion characteristics whilst both drugs remained stable over 6 months and drug dissolution at a salivary pH showed gradual release within 2 h. The results show the potential of CAR 911 and F127 based wafers for buccal mucosa drug delivery.