The real issue in the development of oral controlled release dosage forms is not just to prolong the delivery of drugs but also to prolong the presence of dosage forms in the stomach in order to improve the bioavailability of drugs with a 'narrow absorption window'. In the present study, an anti-ulcer drug, ranitidine hydrochloride, is delivered through a gastroretentive ethyl cellulose-based microparticulate system capable of floating on simulated gastric fluid for > 12 h. Preparation of microparticles is done by solvent evaporation technique with modification by using an ethanol co-solvent system. The formulated microspheres were free flowing with good packability and encapsulation efficiencies were up to 96%. Scanning electron microscopy confirmed porous, spherical particles in the size range 300-750 microm. Microspheres showed excellent buoyancy and a biphasic controlled release pattern with 12h. In vivo bioavailability studies performed on rabbits and T(max), C(max), AUC were calculated and confirmed significant improvement in bioavailability. The data obtained thus suggests that a microparticulate floating delivery system can be successfully designed to give controlled drug delivery, improved oral bioavailability and many other desirable characteristics.

The purpose of this study was to develop floating microparticles containing Pioglitazone HCl, for controlled release and perform pharmacodynamic studies. The FTIR and DSC studies revealed that there is no interaction between drug and excipients used. The 2(2) factorial design was employed to evaluate the effect of drug: polymer (total) and Eudragit RS 100: Eudragit RL 100. The floating microparticles were prepared by solvent evaporation technique. The predicted and actual values of drug release at 1 h, 8 h and drug entrapment were 38.307%, 77.76%, 84.25% and 38.712%, 76.237% and 84.62%, respectively. XRD and SEM studies showed reduced crystallinity of drug and spherical microparticles. Buoyancy studies revealed good floating of particles for 12 h. Pharmacodynamic studies showed significant reduction in blood glucose levels in male New Zealand rabbits. The results demonstrate the feasibility of the factorial design in successfully developing floating microparticles of Pioglitazone HCl for controlled release.

Objective: To statistically design, optimize and evaluate a liquid oral, floating in situ gel of metformin hydrochloride (MH) to increase the gastric residence time (the absorption window being the upper part of the duodenum), sustain and modulate the release behavior of the drug. No liquid oral SR formulations of MH are yet available in the market. Methods: A simple mixing based ionic cross-linking method was used for the formulation. A Two-square Factorial Design was employed and the effect of sodium alginate and three categorical levels of HPMC (K4M, K100M, E50) on the response variables were studied. Results: The optimized formulation gelled instantaneously in simulated gastric fluid and showed>24 h floating. The drug release in 1h was 37.98 %, followed by a moderate sustained release for 12 h. Pharmacodynamic studies showed a significant reduction in blood glucose levels in Wistar rats. Short term preclinical safety studies revealed no toxicity to pancreatic tissues. On the contrary, faster regeneration of the β cells of the islets of Langerhans was observed with the group treated with the optimized formulation. Stability studies revealed a 2-year shelf life. Conclusion: An elegant, needle-free, in situ gelling, SR liquid oral of metformin hydrochloride could be developed with drug release modulated as per official specifications for SR formulations of MH. This would be an interesting alternative for geriatric patients who find it difficult to swallow bulky tablets.

The purpose of the present study was to develop an optimized transdermal drug delivery system of curcumin by adopting statistical optimization techniques. The response surface methodology was employed to find the combined effect of independent variables such as concentration of hydroxypropyl methylcellulose HPMC and polyvinylpyrrolidone PVP which significantly influence characteristics such as cumulative drug release up to 24 hours moisture content and folding endurance. Fourier-transform infrared spectroscopy studies were performed which revealed no interaction between drug and excipients. According to two factorial design the composition of optimized film contained 200 mg of HPMC and 50 mg of PVP. The optimized patch exhibited a cumulative drug release of 70.21 at the 24th hour moisture content of 12.45 and a folding endurance of 83 thus showing good physicochemical and mechanical properties. It could be concluded that by employing statistical optimization techniques a transdermal herbal patch of curcumin with good drug release characteristics and other desirable properties can be developed. This warrants the need for further studies to be conducted that test the efficacy of this formulation in dairy cattle.

Aim: The present study aims at the development of a sustained release liquid oral in situ gel of the antiasthmatic drug montelukast sodium with improved bioavailability and patient compliance. The drug has a short biological half-life of 2.5-5.5 h, an oral bioavailability of 64% and is commercially available only as solid dosage forms. Materials and Methods: The formulations were statistically designed using central composite design, suitable proportions of thermosensitive polymers such as Pluronic F127, Xyloglucan and other excipients added and a simple mixing (cold method) used for the preparation. The effect of the factors on various responses was evaluated and optimization was done. Results: The optimized formulation showed a mean viscosity of 0.039 Pas, gelled at body temperature, gave 94.18 ± 2.15 % drug release in 12 h. In vivo studies on New Zealand male rabbits revealed a C max of 192.91 ± 13.363 ng/ml in 1 h and 12 h sustained release. The AUC 0-α (4767.942 ± 412.915 ng h/ml) showed 3.8-fold increase in bioavailability. Stability studies indicated a 2-year shelf life at 4°C. ϴ test (0.78690) < ϴ std (0.7963) obtained using Earth mover's distance revealed that the pharmacokinetic profile of the optimized formulation was better than the reference drug solution. Conclusion: This elegant, less bulky, liquid oral in situ gelling system with pH-independent release would also be patient compliant and could pave way for a better approach to drug delivery.