International Journal of Pharmaceutical Sciences and Drug Research

01-09

Authors: Mahendar Rupavath*, K. S. K Rao Patnaik

The objective of the present investigation was to identify a suitable raft forming agent and to develop raft forming stavudine matrix tablets using different rate controlling natural, semi-synthetic and synthetic polymers to achieve prolonged gastric residence time, leading to an increase in drug bioavailability and patient compliance. Various raft forming agents were used in preliminary screening. Raft forming floating tablets were developed using pullulan gum as natural rate controlling polymer, and directly compressible grades of hydroxypropyl methylcellulose (Benecel K4M DC) as semi synthetic, and Carbopol 71G as synthetic rate controlling polymers respectively and optimum concentrations of sodium-bicarbonate as gas generating agent to generate optimum buoyancy by direct compression method. Raft forming tablets were evaluated for weight variation, thickness, hardness, friability, drug content, in vitro drug release, floating buoyancy and raft strength. Drug-excipients compatibility study showed no interaction between drug and excipients. Raft forming tablets showed satisfactory results when evaluated for weight variation, thickness, hardness, friability, drug content, and raft strength. The optimized formulation was selected based on physicochemical characteristics and in vitro drug dissolution characteristics. Further, the optimized formulation was evaluated for in vivo radiographic studies by incorporating BaSO4 as radio opaque substance. Optimized formulation showed controlled and prolonged drug release profiles while floating and raft formation over the dissolution medium. Diffusion followed by erosion with raft forming drug release mechanism was observed for the formulation, indicating that dissolution media diffusion and polymer erosion played an essential role in drug release. In vivo radiographic studies revealed that the raft forming formulations remained in the stomach for 240 ± 30 min in rabbits and indicated that gastric retention time was increased by the floating and raft forming principle, which was considered and desirable for absorption window drugs.

17-21

Authors: Simanchal Dash1, B. K. Garnaik2*

The present study focused on the preparation and antioxidant studies of inclusion complexes of some compounds of 4-Thiazolidinone derivatives with β-cyclodextrin. The inclusion complex has been prepared in order to increase solubility and bio-accessibility of the parent compound. The experiment was conducted by taking 2-Hydrazinobenzothiazole as a starting material and a series of compounds and their inclusion is prepared from it. Taking into account on their physical, thermal and spectral characteristics (UV, IR and NMR), the formation of compounds and their inclusion complex are confirmed. From the antioxidant activities of compounds and inclusion complex, it has been found that inclusion complex has displayed more effectively than the original compounds.

30-33

Authors: C. Girish1, Y. Narsimha Reddy2*

Anaphylaxis is the result of alteration in mast cell physiology and is responsible for the various physiological changes which are observed during anaphylaxis. The symptoms of anaphylaxis are due to the release of the histamine from the mast cells and it results mainly due to the degranulation of the mast cells. Antianaphylactic activity of polyherbal formulation against passive anaphylaxis was evaluated with the help of sheep serum induced passive anaphylaxis model and passive paw anaphylaxis model. Sheep serum induced passive anaphylaxis model was carried out by wistar rats. The selected rats were administered intraperitoneally with serum of active anaphylactic rats. After 48 h all the rats are administered intraperitoneally with 1ml of sheep serum. The rats which are pre-treated with prednisolone (10 mg), polyherbal formulation (250 mg) were analyzed for the mast cell degranulation. Passive paw anaphylaxis model was carried out by subcutaneous administration of 0.1 ml serum of active anaphylactic rats into the plantar region of left hind paw of rats. After 24 h the left hind paw of rats was administered subcutaneously with 0.1 ml of egg albumin. The rats which are pre-treated with prednisolone (10 mg), polyherbal formulation (250 mg) were analyzed for the increase in paw volume. Antianaphylactic activity of polyherbal formulation on the mesenteric mast cells of the rat may be possibly due to the membrane stabilizing potential.