The absolute bioavailability of famotidine after oral administration is about 40–45% and absorbance only in the initial part of small intestine may be due to low intestinal permeability. Hence, an olive oil based microemulsion formulation with Tween-80 as surfactant and PEG-400 as cosurfactant was developed by using water titration method with the aim of enhancing the intestinal permeability as well as oral bioavailability. In vitro drug permeation in intestine after 8 h for all formulations varied from 30.42% to 78.39% and most of the formulations showed enhanced permeation compared to pure drug (48.92%). Famotidine microemulsion exhibited the higher absorption and C max⁡ achieved from the optimized famotidine formulation (456.20 ng·h/ml) was higher than the standard (126.80 ng·h/mL). It was found that AUC0–24 h obtained from the optimized famotidine test formulation (3023.5 ng·h/mL) was significantly higher than the standard famotidine (1663.3 ng·h/mL). F-1 demonstrated a longer (6 h) T max⁡ compared with standard drug (2 h) and sustained the release of drug over 24 h. The bioavailability of F-1 formulation was about 1.8-fold higher than that of standard drug. This enhanced bioavailability of famotidine loaded in microemulsion system might be due to increased intestinal permeability.

Pravastatin Sodium has a cholesterol lowering agent. It has shorter half-life and undergoes first-pass metabolism. Frequent dose is required in case of conventional dosage form. The purpose of the study is to formulate and evaluate microcapsules containing Pravastatin Sodium by complex with cholestyramine resins coated with Eudragit RLPO and Eudragit RSPO polymers for achieving control release. Complexation of drug on resin was carried out by batch method. Microencapsulation was carried out by nonaqueous solvent evaporation method. Pharmacokinetic studies were done by using rats. The intermediate stability studies were carried out on the most satisfactory formulations. FTIR, X-ray diffraction, and DSC spectra of drug, drug-resinates, and polymers revealed no chemical interaction. The % DEE and % yield were observed for formulations of f1 to f7 that were varied from 97.1 ± 0.8 to 98.9 ± 0.5% and 95.0 ± 3.25 to 98.8 ± 7.1%, respectively. Most satisfactory formulation, f6, showed drug release up to 72.6%. No changes in % DEE and % CDR were observed after stability studies. Microcapsules of f6 formulation achieved best performance regarding in vitro drug release and from pharmacokinetic evaluation mean residence time was found to be 6.3 h, thus indicated, Pravastatin Sodium microcapsules were released and absorbed slowly over a prolonged period of time.

Ranitidine microemulsion was investigated for its pharmacodynamic and pharmacokinetic evaluation to find out the suitability of microemulsion as a potential drug delivery system in the treatment of ulcer. The bioavailability of ranitidine after oral administration is about 50% and is absorbed via the small intestine; this may be due to low intestinal permeability. Hence the aim of present investigation was to maximize the therapeutic efficacy of ranitidine by developing microemulsion to increase the intestinal permeability as well as bioavailability. A ground nut oil based microemulsion formulation with Tween-80 as surfactant and PEG-400 as cosurfactant was developed for oral delivery of ranitidine and characterized for physicochemical parameters. In pharmacodynamic studies, significant ( < 0.05) variation in parameters estimated was found between the treated and control groups. Ranitidine microemulsion exhibited higher absorption and C max (863.20 ng⋅h/mL) than the standard (442.20 ng/mL). It was found that AUC 0−24 hr obtained from the optimized ranitidine test formulation (5426.5 ng⋅h/mL) was significantly higher than the standard ranitidine (3920.4 ng⋅h/mL). The bioavailability of optimized formulation was about 1.4-fold higher than that of standard drug. This enhanced bioavailability of ranitidine microemulsion may be used as an effective and alternative drug delivery system for the antiulcer therapy.