M. Himaja

Bio: M. Himaja is an academic researcher from VIT University. The author has contributed to research in topics: Amino acid & Tetrapeptide. The author has an hindex of 10, co-authored 72 publications receiving 394 citations. Previous affiliations of M. Himaja include Mangalore University.

Design and evaluation of mucoadhesive buccal drug delivery systems containing metoprolol tartrate

Abstract: Mucoadhesive buccal tablets of metoprolol tartarate were fabricated with objective of avoiding first pass metabolism and prolonging duration of action. The mucoadhesive polymers used in formulation were Carbopol-934, hydroxypropylmethylcellulose, hydroxyethylcellulose and sodium carboxymethylcellulose. The formulations were characterized for physiochemical parameters, in vitro release studies and in vivo placebo studies. The best mucoadhesive performance and in vitro drug release profile were exhibited by the tablets containing hydroxyethylcellulose and Carbopol-934 in ratio 1:2. This product was more comfortable to the user due to absence of erosion, faster hydration rate and less viscosity of surrounding environment. In vivo placebo studies did not show any side effects.

Investigation of Enhancement of Solubility of Norfloxacin β-Cyclodextrin in Presence of Acidic Solubilizing Additives

Abstract: The present study is aimed at improving the solubility of a poorly water-soluble drug, norfloxacin by incorporating solubilizing additives such as ascorbic acid and citric acid into the β-cyclodextrin complexes. Norfloxacin, being amphoteric in nature, exhibits a higher solubility at pH below 4 and above 8. Addition of substances like ascorbic acid and citric acid in β-cyclodextrin complexes reduces the pH of the immediate microenvironment of the drug below pH 4. In the present work, β-cyclodextrin complexes of norfloxacin were prepared along with solubilizing additives such as citric acid and ascorbic acid in various proportion and the dissolution profile was performed in both HCl buffer, pH 1.2 and phosphate buffer, pH 7.4. The results have shown an enhanced dissolution rate in both media. DSC and IR spectral studies performed on the solid complexes have shown that there is no interaction of the drug with the additives and β-cyclodextrin. Disc diffusion studies have shown larger diameters of zone of inhibition indicating a greater diffusivity of the drug into the agar medium.

First total synthesis and biological screening of hymenamide E.

Abstract: A new potent bioactive, proline-rich cyclic heptapeptide hymenamide E (13) was synthesized using the solution phase technique by cyclization of the linear peptide Boc- -Phe-Pro-Thr-Thr-Pro-Tyr-Phe-OMe (12) after proper de- protection at carboxyl and amino terminals. Linear pep- tide segment was prepared by coupling the tripeptide unit Boc-Phe-Pro-Thr-OH (10a) with the tetrapeptide unit Thr-Pro-Tyr-Phe-OMe (11a) using dicyclohexylcarbodi- imide as the coupling agent and N-methylmorpholine as the base. Structures of all new compounds were charac- terized by IR, 1 H NMR spectral data as well as elemental analyses. In addition, the structure of compound 13 was verified by 13 C NMR, fast atom bombardment mass spec- troscopy and differential scanning calorimetry. The newly synthesized cyclopeptide was screened for its antibacte- rial, antifungal and anthelmintic activities against eight pa- thogenic microbes and two earthworm species. Compo- und 13 showed potent antifungal activity against Candida albicans and Ganoderma species comparable to that of gri- seofulvin as a reference drug and potent anthelmintic ac- tivity against earthworms Megascoplex konkanensis and Eudrilus species in comparison to piperazine citrate.

Dissolution enhancement of aceclofenac through solid dispersions

Abstract: The present study was aimed at improving the dissolution of poorly soluble drug, aceclofenac, using solid dispersion (SD) technique. SDs were prepared in different proportions using hydrophilic carriers like mannitol and urea. The differential scanning calorimetry (DSC) thermograms and infra red (IR) spectra revealed that there was no interaction of aceclofenac with additives and no degradation in aceclofenac molecule. The dissolution rate studies were performed in phosphate buffer (simulated intestinal fluid). SDs gave faster dissolution rate when compared to corresponding physical mixture and pure drug.

Antibacterial and antioxidant potential of biosynthesized copper nanoparticles mediated through Cissus arnotiana plant extract.

Abstract: Environment friendly methods for the synthesis of copper nanoparticles have become a valuable trend in the current scenario. The utilization of phytochemicals from plant extracts has become a unique technology for the synthesis of nanoparticles, as they possess dual nature of reducing and capping agents to the nanoparticles. In the present investigation we have synthesized copper nanoparticles (CuNPs) using a rare medicinal plant Cissus arnotiana and evaluated their antibacterial activity against gram negative and gram positive bacteria. The morphology and characterization of the synthesized CuNPs were studied and done using UV-Visible spectroscopy at a wavelength range of 350–380 nm. XRD studies were performed for analyzing the crystalline nature; SEM and TEM for evaluating the spherical shape within the size range of 60–90 nm and AFM was performed to check the surface roughness. The biosynthesized CuNPs showed better antibacterial activity against the gram-negative bacteria, E. coli with an inhibition zone of 22.20 ± 0.16 mm at 75 μg/ml. The antioxidant property observed was comparatively equal with the standard antioxidant agent ascorbic acid at a maximum concentration of 40 μg/ ml. This is the first study reported on C. arnotiana mediated biosynthesis of copper nanoparticles, where we believe that the findings can pave way for a new direction in the field of nanotechnology and nanomedicine where there is a significant potential for antibacterial and antioxidant activities. We predict that, these could lead to an exponential increase in the field of biomedical applications, with the utilization of green synthesized CuNPs, due to its remarkable properties. The highest antibacterial property was observed with gram-negative strains mainly, E. coli , due to its thin peptidoglycan layer and electrostatic interactions between the bacterial cell wall and CuNPs surfaces. Hence, CuNPs can be potent therapeutic agents in several biomedical applications, which are yet to be explored in the near future.

The cyclization of peptides and depsipeptides

Abstract: Constricting the peptide backbone into a more defined conformational form through cyclization is an activity evolved in nature and in synthetic work, the latter straddling only the most recent decades. The resulting conformational constraints increase the probability of an optimum response with bio-receptors. The purpose of this review is to highlight developments that have proved to be reasonably efficient in the macrocyclization of linear precursors into cyclic peptides and depsipeptides.