FORMULATION AND EVALUATION OF BILAYERED TABLETS OF MONTELUKAST AND LEVOCETRIZINE DIHYDROCHLORIDE USING NATURAL AND SYNTHETIC POLYMERS

The objective of present work was to formulate and evaluate bilayered tablets of Levocetrzine and Montelukast for treating allergic rhinitis effectively. Anti-allergic medicines (eg, some antihistamines) can cause adverse events such as somnolence and sedation. The Combining Montelukast with Levocetirizine gives additional benefits in comparison with either drug alone and could be considered for patients whose quality of life is impaired by persistent allergic rhinitis. Montelukast sodium is alkaline stable (bioavailability 64%), most of drug being absorbed from the intestine while Levocetirizine Dihydrochloride is acid stable. When tablets of the combination of these are  prepared, they tend to become unstable during the shelf life of the formulation. Hence it is recommended to prepare a bilayer tablet, by formulating Montelukast in sustained release layer and Levocetrizine as immediate release layer as it improves and increases the stability by reducing the acid base interactions of both the drugs in combination there by increasing the bioavailability. Taking this into account different formulations were prepared by wet granulation method using natural Tamarind Seed Polysaccharide and synthetic HPMCK100,K15M and K4M release rate controlling hydrophilic polymers. The formulations were evaluated for hardness, weight variation, friability, swelling index and drug content uniformity. The in vitro release of drug from the formulations was studied in pH 1.2 acidic buffer and pH 7.4 phosphate buffer, and it was found that the prepared tablets were able to sustain the release of the drug upto 12hours. The release of Montelukast and Levocetrizine of both layers from the tablets was found to be diffusion controlled and the release mechanism was non-Fickian based on the n value of Korsmeyer-peppas plot. The FTIR studies were performed on three optimized formulations (F4, F12, F16) and the plain drug controls(Levocetrizine,Montelukast).From the  observed peaks it is evident that the polymers used and the drugs were  found to be mutually compatible chemically. The Pharmacokinetic Studies were performed in two groups of male wistar rats. One group was administered with the optimized formulation containing tamarind Seed Polysaccharide(F12) while Plain Montelukast oral suspension acted as control in the second group.The results indicate that the formulation optimised with 1:4(drug:TSP) was able to sustain the release of montelukast upto 12hours.Insrease in Tmax and AUC(0-α) also were also observed in the studies indicating efficient sustained action and improved bioavailability of the drug. The formulated bilayered tablets using natural polymers provided immediate release of Levocetrizine and sustained release of Montelukast and therefore hold promise as an alternative dosage form in the treatment of allergic rhinitis and bronchial asthma. Key words: Tamarind Seed Polysacharide, Hydroxypropyl methyl cellulose,  Bilayered tablets

Expression of Osteoarthritis Marker YKL-39 is Stimulated by Transforming Growth Factor Beta (TGF-beta) and IL-4 in Differentiating Macrophages

YKL-39 is a Glyco_18 domain containing chitinase-like protein which is currently recognized as a biomarker for the activation of chondrocytes and the progress of the osteoarthritis in human. YKL-39 was identified as an abundantly secreted protein in primary culture of human articular chondrocytes. Two biological activities of YKL-39 might contribute to the disease progression. One is the induction of autoimmune response and second is the participation in tissue remodeling. Other mammalian chitinase-like proteins including chitotriosidase, SI-CLP, YKL-40 and YM1 are expressed by macrophages in various pathological conditions. In contrast, YKL-39 was never reported to be produced by macrophages. We used in vitro model of human monocyte-derived macrophage differentiation to analyse regulation of YKL-39 expression. Expression of YKL-39 was examined by real-time RT-PCR. CD14+ MACS sorted human monocytes differentiated for 6 days under different stimulations including IFNγ, IL-4, dexamethasone and TGF-β. We found that both IL-4 and TGF-β have weak stimulatory effect on YKL-39 expression in all donors tested (3.2 ± 1.7 fold, p = 0.006 and 6.3 ± 3.1 fold, p = 0.014 respectively). However the combination of IL-4 and TGF-β had strong stimulatory effect on the expression of YKL-39 in all analysed individual macrophage cultures (34 ± 36 fold, p = 0.05). IFN-γ did not show statistically significant effect of YKL-39 mRNA expression. Presence of dexamethasone almost completely abolished the stimulatory effects of IL-4 and TGF-β. In summary, we show here for the first time, that human cells of monocyte origin are able to produce YKL-39. Maturation of monocyte derived macrophages in the presence of Th2 cytokine IL-4 and TGF-β leads to the strong activation of YKL-39 expression. Thus elevated levels of YKL-39 observed during chronic inflammations can not be attributed solely to the activity of chondrocytes. In perspective, YKL-39 might serve as a useful biomarker to detect macrophage-specific response in pathologies like tumour, atherosclerosis and Alzheimer disease

All-trans retinoic acid up-regulates Prostaglandin-E synthase expression in human macrophages

All-trans retinoic acid (ATRA) is a potent retinoid, which has been used successfully in different clinical settings as a potential drug to treat COPD and emphysema. In the present study, we analyzed genes modulated by ATRA by performing mRNA expression array analysis on alveolar macrophages after treatment with ATRA. Here we observed a 375-fold up-regulation of Prostaglandin-E Synthase (microsomal PGES-1, NM_004878 PTGES) which mediates the conversion of prostaglandin H(2) (PGH(2)) to Prostaglandin E(2) (PGE(2)). We furthermore studied the expression of PTGES after treatment with ATRA in human monocyte-derived macrophages (MDMs) and bronchoalveolar lavage (BAL) cells. ATRA up-regulated PTGES mRNA expression in MDMs generated with M-CSF by 2500-fold whereas in M-CSF+IL-13 macrophages the up-regulation was only 20-fold. Similarly, ATRA up-regulated PTGES mRNA expression by factor 1524 in BAL cells. The up-regulation of PTGES mRNA expression by ATRA is both time and dose dependent. IL-13 suppressed the ATRA induced PTGES expression at both mRNA and protein level in MDM and BAL cells. We also observed that LPS acts synergistically with ATRA in MDMs and strongly induces PTGES expression. ATRA had little impact on cyclooxygenase-1 and -2 (COX-1 and -2) expression as compared to PTGES expression under the same experimental conditions. Furthermore, we observed an induction of PGE(2) levels by ATRA in BAL cells. These data indicate that ATRA is a potent inducer of PTGES expression in human macrophages but not in alternatively activated macrophages and suggest that the eicosanoid pathway is important for ATRA action in macrophages

A Novel GGA-Binding Site Is Required for Intracellular Sorting Mediated by Stabilin-1▿

Stabilin-1 is a unique scavenger receptor that combines endocytic and intracellular sorting functions in macrophages. Stabilin-1 mediates the endocytosis of acetylated low-density lipoprotein (acLDL), SPARC, and growth hormone family member placental lactogen (PL). At the same time, stabilin-1 is involved in trans-Golgi network-to-endosome routing of the endogenous chitinase-like protein SI-CLP (stabilin-interacting chitinase-like protein). A DDSLL motif in the cytoplasmic tail of stabilin-1 interacts with GGA adaptors; however, the deletion of DDSLL reduces but does not abrogate this interaction. Here, we identified a novel GGA-binding site, EDDADDD, in the cytoplasmic tail of stabilin-1. The deletion of EDDADDD impaired and the deletion of both the DDSLL and EDDADDD sites abrogated the interaction of stabilin-1 with GGAs. The surface exposure of stabilin-1 and stabilin-1-mediated endocytosis of acLDL, SPARC, and PL were not affected by the deletion either of DDSLL or EDDADDD or both. At the same time, both GGA-binding sites were necessary for the intracellular sorting of SI-CLP performed by stabilin-1. Our data indicate that the novel GGA-binding site EDDADDD is essential for stabilin-1-mediated intracellular sorting but is not required for endocytosis