Spray Drying as an Approach for Enhancement of Dissolution and Bioavailability of Raloxifene Hydrochloride.

The present study investigated the effect of spray drying raloxifene HCl (RHCL) with different classes of hydrophilic carriers (different grades of polyvinyl pyrrolidones) and cellulosic polymers) in order to determine the potential effect on dissolution rate and bioavailability of RHCL. Pre-formulation studies were conducted to select the appropriate carriers and drug:carrier ratio for preparing the spray dried compositions.The solid state interactions of the spray dried mixtures were evaluated by DSC & XRD. Preformulation studies revealed that amorphous compositions of RHCL could be obtained only with Plasdones (K12, K29/32 and S630). DSC studies showed that the crystalline nature of RHCL was significantly reduced on spray drying. Significant enhancement in dissolution rate was observed with the prepared spray dried compositions and out of the three grades of Plasdone, Plasdone K12 demonstrated the maximum enhancement in rate of release of RHCL. The pharmacokinetics of spray dried composition (1:1 RHCL: K12) and pure RHCL was evaluated following oral administration (25 mg/kg) in healthy female Sprague Dawley rats. The extent of the mean plasma exposures of RHCL was 7-fold higher in animals treated with spray dried mixture of RHCL, K12 (1:1) compared to animals treated with RHCL. Spray drying of RHCL with Plasdones, especially Plasdone K12, reduced drug crystallinity, increased the rate and extent of dissolution, and improved bioavailability

Development of Buccoadhesive Systems of Pentarocine for Systemic Drug Delivery

Bucoadhesive patches of Pentazocine (PZ) for unidirectional drug delivery were prepared by casting carboxy methyl cellulose (CMC) with glycerol or propylene glycol and CMC-hydroxy ethyl cellulose (HEC) with glycerol. In vitro mucoadhesivity of the prepared patches were determined using a modified mucoadhesive bond strength apparatus using rabbit small intestine mucosa (SIM). Drug release kinetics was evaluated from composite patches, prepared by covering all but one side of the PZ patches with 3M backing material. Biocompatability / buccoadhesion time and in vivo permeation of placebo and PZ loaded patches were determined using a double blind cross over study in healthy human volunteers. Drug release from CMC-glycerol patches and pure HEC patches showed zero order kinetics with diffusional exponent (n) ranging between 0.79 to 1.046, while that from CMC-HEC and CMC-propylene glycol patches showed an apparent zero order release kinetics. The prepared patches were well tolerated by the human volunteers as they did not produce any side effects at the contact surface. The in vitro mucoadhesivity of CMC-propylene glycol patches were significantly lower than CMC- glycerol based patches. The in vivo permeation of selected PZ patches delivered the drug well above the minimum buccal permeation rate, so as to attain effective blood concentratio