Natural gums as sustained release carriers: development of gastroretentive drug delivery system of ziprasidone HCl

<p>Abstract</p> <p>Background</p> <p>Objective of this study is to show the potential use of natural gums in the development of drug delivery systems. Therefore in this work gastro retentive tablet formulations of ziprasidone HCl were developed using simplex lattice design considering concentration of okra gum, locust bean gum and HPMC K4M as independent variables. A response surface plot and multiple regression equations were used to evaluate the effect of independent variables on hardness, f_lag time, floating time and drug release for 1 h, 2 h, and 8 h and for 24 h. A checkpoint batch was also prepared by considering the constraints and desirability of optimized formulation to improve its <it>in vitro</it> performance. Significance of result was analyzed using ANOVA and <it>p < 0.05</it> was considered statistically significant.</p> <p>Results</p> <p>Formulation chiefly contains locust bean gum found to be favorable for hardness and floatability but combined effect of three variables was responsible for the sustained release of drug. The <it>in vitro</it> drug release data of check point batch (F8) was found to be sustained well compared to the most satisfactory formulation (F7) of 7 runs. The ‘n’ value was found to be between 0.5 and 1 suggesting that release of drug follows anomalous (non-fickian) diffusion mechanism indicating both diffusion and erosion mechanism from these natural gums. Predicted results were almost similar to the observed experimental values indicating the accuracy of the design. <it>In vivo</it> floatability test indicated non adherence to the gastric mucosa and tablets remain buoyant for more than 24 h.</p> <p>Conclusions</p> <p>Study showed these eco-friendly natural gums can be considered as promising SR polymers.</p

Pharmacognostical and larvicidal evaluation of Artocarpus lakoocha Roxb. from Western Ghats

Mosquitoes are the most important single group of insects acting as vector for many tropical and subtropical diseases. Using insecticides of plant origin to interrupt the life cycle, vector borne diseases can be controlled. Artocarpus lakoocha Roxb. popularly known as Monkey Jack or Lakuch is ethnobotanically used to treat fever, purge, skin ailments and also as an appetizer. The present study investigated thepharmacognostical and larvicidal activity of leaves and fruits of A. lakoocha against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus larvae. As a step towards standardization of crude drug, the powder microscopy, physico-chemical analysis, TLC studies and HPTLC profiles of active pet ether extract were established. The larvicidal potential of successive solvent extracts were screened and expressed as LC50 values. The pet ether extract of leaves and fruits were significant with LC50 241.36, 624.88, 1162.86 and 1180.95, 1286.69, 1398.69 µg/mL on the three species, respectively compared to other extracts. The results indicate that the triterpenoids and phytosterols present in the pet ether extract exerted a dose dependent larvicidal activity and the malarial vector, An. stephensi was more susceptible to the pet ether extract

Preparation and crystallographic analysis of gliclazide polymorphs

Since the introduction of gliclazide in the pharmaceutical industry, a large number of research groups have been engaged in various investigations aiming to enhance its biomedical application. But, very limited efforts have been made to study polymorphism of gliclazide. Therefore, this study focuses on solvent-induced polymorphism of gliclazide and its characterization by thermal methods. Three polymorphs namely, Form-I, II and III and an amorphous powder were produced from different solvents and solvent mixtures. Crystals were analyzed using infrared spectroscopy, differential scanning calorimetry, X-ray powder diffraction and single crystal x-ray diffraction. Polymorph Form-I is found to exist in centro-symmetric triclinic P-1 space group and has endothermic peak at 162.93°. Form-II has endothermic peak from 171.2° to 172.35° and exists in centro-symmetric monoclinic P2 1 /a space group while Form-III has endothermic peak from 168.93° to 169.86° and exists in centro-symmetric monoclinic P2 1 /n space group. The equilibrium solubility values of Form-I, II, III and the amorphous form were 0.4825±0.025, 0.2341±0.042, 0.2581±0.038 and 0.5213±0.072 mg/ml, respectively. The Form-I has relatively higher solubility and similar to that of amorphous gliclazide. Form-II and Form-III are relatively most stable and least soluble. However, there was no remarkable difference in their aqueous solubility under the conditions in which study was conducted