No abstract

A simple, rapid and sensitive RP-HPLC method was developed for the quantitative determination of tramadol hydrochloride and paracetamol in combined tablet dosage form. The chromatographic analysis was carried out on enable C18G column (250 x 4.6 mm, 5 μm) with mobile phase containing 1 % glacial acetic acid: acetonitrile (50:50 v/v). The flow rate of mobile phase was 1.0 mL/min and effluents were monitored at 272 nm. The retention times of tramadol hydrochloride and paracetamol were 2.032 min and 2.711 min, respectively. The proposed method was validated with respect to linearity, accuracy, precision, specificity and robustness. The method was found to simple, rapid and sensitive and was successfully applied to the estimation of tramadol hydrochloride and paracetamol in combined dosage form.

Pulsatile drug delivery system is one type of drug delivery system, where the delivery device is capable of releasing drugs after a predetermined time-delay (i.e. lag time). This system has a peculiar mechanism of delivering the drug rapidly and completely after a "lag time," i.e., a period of "no drug release." These systems are beneficial for drugs having high first-pass effect drugs administered for diseases that follow chrono pharmacological behavior such as drugs having specific absorption sites in GIT, targeting to colon; and cases where nighttime dosing is required. The objective of the present study was to formulate and evaluate a press coated pulsatile drug delivery system of simvastatin in order to attain a time controlled release to lower the blood cholesterol level by releasing the drug with a distinct predetermined lag time of five hrs. Simvastatin is a water insoluble drug and its absorption is dissolution rate limited. The core formulations were composed of simvastatin and disintegrants like lycoat, SSG, ludiflash in different ratios and was coated with xanthan gum, guar gum, HPMC K4M, HPMC K15M as a release modifier. Press coated tablets were evaluated for hardness, friability, drug content, and in vitro drug release. Result of in vitro dissolution study of the prepared tablet suggested that, the release of drug from press coated tablets match with chrono-biological requirement of disease.

Biologics include vaccines, recombinant proteins, genes, synthetic tissues and viruses, which have emerged from molecular and cellular biology, with respect to unmet clinical needs and expanding indications. Hence it is important at this stage to outline the essential events that have led to the current level of interest in protein and peptide drug delivery systems. Polymers consisting of amino acids that are covalently linked by peptide bonds are known as Proteins and inturn peptides are small proteins composed of few dozen amino acids. Due to large molecular sizes of the proteins ranging from thousands to several millions atomic masses sizes; absorption through the epithelial barriers in the gastrointestinal tract is low. Moreover, proteins are rapidly degraded by digestive enzymes. As the bioavailability by oral route is poor they can be administered by other routes mainly by parenteral (IV, SC, IM) injections. The biological activity of proteins is strongly dependent on their molecular structure i.e 10 structure; the amino acid sequence, which ultimately dictates the non-covalent interactions and the 20i.e alpha helices and beta helices; the periodic spatial arrangement of the polypeptide chain backbone and 30; the 3-dimensional conformation of the whole molecule, including the positions of all amino acid side chains. Some proteins may consist of multiple peptide chains grouped together by non-covalent intermolecular interactions. The arrangement of these subunits relative to each other constitutes the 40structure. An alteration at any level of molecular structure leads to a change or loss of biological activity. The present review focuses on the development of various routes of drug administration, formulation as well as stability aspects of protein and peptide drug delivery system.

Three simple, accurate, sensitive and economical spectrophotometric methods have been developed and subsequently validated for determination of duloxetine hydrochloride in bulk and pharmaceutical formulation. Method A is an extractive spectrophotometric method based on formation of ion-pair complexes of duloxetine hydrochloride with Solochrome Black T, to form pink colored chromogen, which showed a maximum absorption at 512 nm, and obeys Beer’s law in the concentration range of 2-10 μg/mL. Method B is based on the formation of charge transfer complexation reactions of duloxetine hydrochloride with picric acid to form a yellow colored chromogen, which showed maximum absorption at 420 nm and obeys Beer’s law in the concentration range of 5-25 μg/mL. Method C is a UV spectrophotometric method using isopropyl alcohol as solvent, in which absorption maxima was at 290 nm, Beer’s law obeyed in the concentration range of 5-30 μg/mL. The validation of the above methods was done and the results demonstrated that, the procedures were accurate, precise and reproducible. So, the proposed methods can be applied for the routine analysis of duloxetine hydrochloride in bulk drug and in its tablet dosage form.