A COMPREHENSIVE REVIEW ON IN SITU GELS

The current review on in situ gelling systems becomes one of the most popular and prominent. It had a tremendous potential advantage of delivery systems due to many benefits like easy to use simple manufacturing; improve both adherence and patient comfort by minimizing the frequency of drug administration by its unique characteristics feature of sol to gel transition. It also provides in situ gelling nanoemulsions, nanosphere, microspheres, and liposomes. The drawbacks associated with conventional systems of both solutions and gels, such as accurate dosing, ease of administration overcome by using in situ gelling systems. This review focused on definitions, types, advantages, disadvantages, polymers used, and suitable characteristics of polymers, including the preparation of in situ gels covered in the introduction. Approaches, applications, and evaluation of in situ gels were explained with examples

Fabrication and Characterization of Gliclazide Nanocrystals

Purpose: The main aim of the present investigation was to enhance the solubility of poorly soluble Gliclazide by nanocrystallization. Methods: In present investigation gliclazide nanocrystals were prepared by sonoprecipitation using Pluronic F68, Poly Vinyl Alcohol (PVA), Poly ethylene Glycol 6000 (PEG), Poly Vinyl Pyrrolidine (PVP K30) and Sodium Lauryl Sulphate (SLS) as stabilizers. Fourier Transform Infrared Spectroscopic study (FTIR), Differential Scanning Calorimetry (DSC) and X ray diffraction (XRD) studies were conducted to study the drug interactions. Size and zeta potential of the nanocrystals were evaluated. In vitro and in vivo studies of nanocrystals were conducted in comparison to pure gliclazide. Results: The Gliclazide nanocrystals (GN) showed mean particle size of 131±7.7 nm with a zeta potential of -26.6 mV. Stable nanocrystals were formed with 0.5% of PEG 6000. FTIR, DSC and XRD studies of nanocrystals showed absence of interactions and polymorphism. SEM photographs showed a change in morphology of crystals from rod to irregular shape. There is an increase in the saturation solubility and the percentage drug release from formulation GN5 (Optimized Gliclazide Nanocrystals) was found to be 98.5 in 15 min. In the in vivo study, GN5 nanocrystals have reduced the blood glucose level to 296.4±4.26 mg/dl in 12 hr. The nanocrystals showed lower tmax and higher Cmax values as compared to pure gliclazide. Conclusion: The prepared nanocrystals of gliclazide were stable without any drug polymer interactions. Increase in the dissolution of nanocrystals compared to pure gliclazide and significant reduction in blood glucose level in vivo indicated better bioavailability of the nanocrystals. Therefore, it is concluded that nanocrystal technology can be a promising tool to improve solubility and hence dissolution of a hydrophobic drug

Improved dissolution and micromeritic properties of naproxen from spherical agglomerates: preparation, in vitro and in vivo characterization

Naproxen, an anti-inflammatory drug, exhibits poor aqueous solubility, which limits the pharmacological effects. The present work was carried out to study the effect of agglomeration on micromeritic properties and dissolution. Naproxen agglomerates were prepared by using a three solvents system composed of acetone (good solvent), water (non-solvent) and dichloromethane (bridging liquid). Differential Scanning Calorimetry (DSC) results showed no change in the drug after crystallization process. X-Ray Powder Diffraction (XRPD) studies showed the sharp peaks are present in the diffractograms of spherical agglomerates with minor reduction in height of the peaks. The residual solvents are largely below the tolerated limits in the agglomerates. Scanning Electronic Microscopy (SEM) studies showed that agglomerates were spherical in structure and formed by cluster of small crystals. The agglomerates exhibited improved solubility, dissolution rate and micromeritic properties compared to pure drug. Anti-inflammatory studies were conducted in Wistar strain male albino rats and naproxen agglomerates showed more significant activity than the pure drug.<br>Naproxeno, fármaco anti-inflamatório, apresenta baixa solubilidade em água, o que limita os efeitos farmacológicos. O presente trabalho foi realizado para estudar o efeito da aglomeração nas propriedades micromeríticas e na dissolução. Aglomerados de naproxeno foram preparados por meio da utilização de sistema de três solventes composto de acetona (bom solvente), água (não-solvente) e diclorometano (líquido de ligação). A DSC não resulta mostrou nenhuma mudança na droga depois de processo de cristalização. Estudos de difração de Raios X do Pó (XRPD) mostraram picos agudos nos difratogramas de aglomerados esféricos, com redução mínima dea altura dos picos. Os solventes residuais estão amplamente abaixo dos limites tolerados nos aglomerados. Os estudos de Microscopia Eletrônica de Varredura (SEM) mostraram que esses aglomerados eram de estrutura esférica e formados por grupos de pequenos cristais. Os aglomerados apresentaram solubilidade, taxa de dissolução e propriedades micromeríticas aprimoradas em comparação com o fármaco puro. Estudos anti-inflamatórios foram conduzidos em ratos Wistar albinos masculinos e os aglomerados de naproxeno mostraram atividade mais significativa do que o fármaco puro