Parenteral route is preferred for low molecular weight heparin (LMWH) due to poor oral bioavailability. Biodegradable formulation components were evaluated for possible interactions between the physical mixtures using differential scanning calorimetry. LMWH and an absorption enhancer papain were encapsulated in bovine serum albumin matrix and four formulations were spray-dried (MS.1, MS.2, MS.3, MS.4). Formulations were evaluated for product yield, particle size, particle charge and encapsulation efficiency. In vitro release assessed in pH 7.2 phosphate buffer saline (PBS) revealed a burst release effect (60%) for all the formulations except MS.1. In vivo studies performed in male Sprague Dawley rats showed an enhancement in drug absorption for the MS.2 and MS.3 formulations because of papain action on paracellular tight junctions. A significant increase in LMWH oral bioavailability was demonstrated by MS.3 (21%), among the formulations encapsulated with papain.

Oral vaccination has long been regarded as the best alternative to conventional parenteral vaccination considering practical, economical, and immunological aspects. The purpose of this study was to develop albumin-chitosan mixed matrix microsphere-filled coated capsule formulations of Typhoid Vi antigen and to determine whether it can induce antigen-specific mucosal and systemic immune responses on oral administration. Formulations with Typhoid Vi antigen were prepared and filled into hard gelatin capsules (size # 9) and enteric coated. Formulations were characterized and administered to Sprague-Dawley rats to evaluate the induction of immune response to the antigen. The results indicated that the particle size, zeta potential, swelling, and disintegration rates were optimal for the oral delivery of microencapsulated vaccines. In vivo studies displayed multifold increase of antigen-specific IgG and IgA levels 8 weeks after oral immunization. No statistically significant difference in the antigen-specific IgG and IgA levels were found between oral and parenteral injection groups 8 weeks after vaccination. On the basis of the results of the study, it can be concluded that the oral administration of Typhoid Vi antigen microspheres was successful in inducing antigen-specific systemic and mucosal immune response.

The aim of this study was to formulate and characterize microspheres containing antisense oligonucleotide to NF-kappaB using bovine serum albumin as the polymer matrix. Microspheres were prepared by spray-drying technique with 5, 10 and 15% drug loading. Glutaraldehyde was used as a cross-linking agent. The particle sizes ranged from 3-5 microm. Microspheres were smooth and spherical in shape, as determined by scanning electron microscopy (SEM). The yield of microspheres ranged from 70-75% and the encapsulation efficiencies were found to be in the range of 59-60%, as determined by a novel HPLC method. Zeta potential of the microspheres ranged between -39 to -53 mV, thus indicating good suspension stability in water. In-vitro release studies performed using phosphate buffer saline demonstrated extended drug release up to 72 h. Kinetic model fitting showed high correlation with the Higuchi model, suggesting that the drug release was primarily diffusion controlled.

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