The main goal of any drug delivery system is to achieve desired concentration of the drug in blood or tissue, which is therapeutically effective and non toxic for a prolonged period. Various attempts have been made to develop gastroretentive delivery systems such as high density system, swelling, floating system. The recent developments of FDDS including the physiological and formulation variables affecting gastric retention, approaches to design single-unit and multiple-unit floating systems, and their classification and formulation aspects are covered in detail. Gastric emptying is a complex process and makes in vivo performance of the drug delivery systems uncertain. In order to avoid this variability, efforts have been made to increase the retention time of the drug-delivery systems for more than 12 hours. The floating or hydrodynamically controlled drug delivery systems are useful in such application. Background of the research: Diltiazem HCL (DTZ), has short biological half life of 3-4 h, requires rather high frequency of administration. Due to repeated administration there may be chances of patient incompliance and toxicity problems. Objective: The objective of study was to develop sustained release alginate beads of DTZ for reduction in dosing frequency, high bioavailability & better patient compliance. Methodology:   Five formulations prepared by using different drug to polymer ratios, were evaluated for relevant parameters and compared. Alginate beads were prepared by ionotropic external gelation technique using CaCl2 as cross linking agent. Prepared beads were evaluated for % yield, entrapment efficiency, swelling index in 0.1N HCL, drug release study and SEM analysis. . In order to improve %EE and drug release, LMP and sunflower oil were used as co-polymers along with sodium alginate.

Novel drug delivery systems (NDDS) are one of the most strategies which enable to overcome the problems related to drug bioavailability. It is the rate and extent to which a drug becomes available to the target tissue after its administration. Most of the new drugs used today have poor bioavailability and are required to be administered at higher doses because only a small fraction of the administered dose is absorbed in the systemic circulation and able to reach the target site. This results in the wastage of major amount of drug and lead to adverse effects. Pharmaceutical technology mainly focuses on enhancing the solubility and permeability of drugs with lower bioavailability.  Nanotechnology is the concept used in NDDS that enables a weight reduction of drug particles accompanied by an increase in stability and improved functionality. Various approaches such as nanosuspensions, liposomes, niosomes, nanoemulsions, cubosomes, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), cyclodextrins, phytosome etc., are used for the enhancement of bioavailability.  The present review focuses on the different approaches used for bioavailability enhancement along with their advantages and disadvantages

Antacid activity evaluation was done using Rossett-Rice method. The in vitro acid neutralization capacity of the drug product was evaluate against standard NaHCO3 and Rossett-Rice time i.e. the time during which the pH maintained between pH 3.0 and 5. It was found that 5mL dose maintained the pH above 3 for 4.11±0.10 min; 10 mL of dose maintained the pH 10.10±0.10 min. and 20 mL of dose maintained the pH 25.10±0.15 min respectively as compared to standard 2.5 mg NaHCO3 which maintained the pH for 10.08±.010 min. The drug having antacid activity should have an adequate duration of action that can maintain the pH of stomach above 3. 10 mL and 20 mL dose of the product shown in vitro similar antacid properties and having significant reactivity towards the acid. Hence the drug product having good acid resistance property.