Characterization

Black pepper, also designated as ‘King of spices’ a characteristic familiar global spice related to the Piperaceae family and generally used in culinary and medicinal preparations. Its pungency is due to piperine, volatile elements and essential oil. Piperine is an amide alkaloid, effective bioactive present in piper species of black and long peppers; and reveals several potential therapeutic actions to intervene different disease conditions whereas functional group responses at active site liable to act as a xenobiotic bio-enhancer and an effective CNS stimulant. However, piperine is slightly soluble in water, limiting its pharmacological activities and biomedical services. It is solid crystalline nature, mild basic, initially tasteless while, a burning after taste. Therefore, this bioactive natural substance should be considered in the arenas of rational drug design and development of formulations. Recent developments in drug delivery system have to overcome its limitations, including poor bioavailability and blood–brain barrier permeability.  Chaperons like phytosomes are encouraging tools to alter oral absorption of piperine. The study highlights the prepared and correctly recognized piperine-phospholipid complex (PPC) in terms of FT-IR (Fourier Transform Infra-red spectroscopy), DSC (differential scanning calorimetry), XRPD (X-ray powder diffractometry), and SEM (scanning electron microscopy). The PPC was found to be fine and loose, airy, light, rough surface with improved water solubility and bioavailability.

Microspheres are free flowing particles ranging from 1-1000u. Microspheres are having wide applications in drug delivery system. They are mainly used for targeted drug delivery of anti-cancer agents, ophthalmic agent and can be used for diagnosis purpose. In this article detail discussion was made on the polymers, preparation methods and applications of microspheres in pharmaceutical dosage form development. General methods of preparation are emulsion techniques, phase separation coacervation techniques, spray drying and spray congealing and solvent extraction, in-situ polymerization etc.  Advantages of microspheres use are targeted drug delivery, optimal therapeutic effects and minimum side effects. Recent trends are floating microspheres, radio immobilization using microspheres. Gastro-retentive floating microspheres are low-density systems that have sufficient buoyancy to float over gastric contents and remain in stomach for prolonged period. The drug is released slowly at desired rate resulting in increased gastric retention with reduced fluctuations in plasma drug concentration.

9,10-Bicyclo-3-substituted-pyrazine-2-(1H)-one was prepared by mixing substituted  aromatic diamine and 2-oxo-2-substituteted acetic  acid in aq. HCl and then stirred at 400Cfor 4 hrs. Progress of the reaction by the formation of thick solid & it was monitored  by TLC ( ethyl acetate /Hexane ,1:1) After the completion of the reaction, the solid product was filtered, washed with the water and dried .The crude product was purified by dissolving in hot aqueous NaOH followed by neutralization with acetic acid. The isolated product was recrystalised from  methyl isobutyl ketone. The compounds thus synthesized have been characterized by physical and spectral data. All of these titled synthesized compounds have been screened for antimicrobial study and  are found to possesses excellent antimicrobial activities.

A novel, simple and rapid reversed-phase liquid chromatography mass spectrometric method (LC-MS) was developed and subsequently used for the characterization of Drotaverine hydrochloride (DRH) and its impurities. The separation was achieved in 22 minutes on Merck Purosphere STAR RP-18e (250 x 4.6) mm, 5 µm column in gradient mode with flow rate 1.5 mL/min. 0.05 M ammonium acetate buffer pH 3.0 and a mixture of acetonitrile and methanol 85:15 v/v  was used as mobile phase A and mobile phase B, respectively. Detection was carried out at the optimum wavelength of 280 nm using a photodiode array/triple quadrupole mass detectors. The retention time of Drotaverine was found about 7 minutes. Specificity of the method was established by blank solution and the extreme degraded sample was used for the detection of impurity masses. The impurities detected under mass detector were further ionized for their daughter ions.

A new azo dye Schiff base ligand, namely N, N′-bis (5-(4-nitrophenyl) diazenyl)-2-hydroxybenzylideneamino)ethylenediimine (NDHBDED) has been synthesized and characterized by analytical techniques. And transition metal complexes of Mn (II), Co (II), Cu (II) and Ni (II) were synthesized by the derived azo dye Schiff base. The complexes were characterized for the elemental analysis, molecular weight determination, electronic spectra, spectral analysis, pH metric method, conductance measurement, magnetic moment measurement at room temperature. Analytical data reveal that Mn (II), Co (II), Cu (II) and Ni (II) complexes posses 1:1 metal-ligand ratios. Schiff base and synthesized complexes were screened for antibacterial and antifungal activities. Co (II) and Cu (II) complexes have been found to be more effective for antimicrobial activity.

A number of resins (2,4DHAPDF) were synthesized by condensation of 2,4 dihydroxyacetophenone (2,4-DHA) and p-phenylenediamine (p-PD )with formaldehyde (F) in the presence of 2 M HCl as a catalyst with three different molar ratios of reacting monomers (1:1:2, 2:1:3, 3:1:4) at 1300C ±20C. Resins have been characterized by elemental analysis, infrared (IR) spectroscopy and nuclear magnetic resonance (1HNMR) spectroscopy and the morphology of the resin was examined by SEM technique. The number average molecular weight of the resin was determined by non –aqueous conductometric titration. The antimicrobial activities of the terpolymer were screened on various bacteria and fungi. All the synthetic terpolymer showed excellent antimicrobial activities with increasing molar ratios of reacting monomers.

The current practice of characterization and control of impurities in pharmaceuticals is reviewed with emphasis on issues specific to the generic industry. This review includes an overview of FDA, ICH, TGA, TPD and EMEA guidelines related to impurities in Drug Substance and Drug Products. This introduces the identification, characterization and qualification procedures for ANDAs and approaches to the establishment of acceptance criteria for both drug substance and drug product and significance of analytical methods in total process.