Abstract The combination of drugs may be a result of a necessary therapeutic strategy against a single disease or a fortuitous treatment of two or more health disorders. In either case, a consequence of such approach is the increased risk of drug interactions and subsequent adverse effects. For the elderly, the probability of these events is significantly increased compared to other age groups, not only because of combining medications but also agerelated pharmacokinetic (absorption, distribution, biotransformation and excretion processes) alteration. Since the growth rate of the elderly population worldwide is rapidly increasing, clinicians should be extremely cautious of the drugs prescribed to older patients in order to minimize drug interactions and therapeutic failure.

Abstract Three sensitive , selective and precise stability indicating methods for simultaneous determination of Paracetamol and Diphenhydramine hydrochloride in their binary mixture and in presence of P-aminophenol; the potential impurity and degradation product of Paracetamol; were developed. In Method A, Paracetamol was determined in presence of Diphenhydramine Hydrochloride and P-aminophenol using the first derivative (1D) spectrophotometric method by measuring the peak amplitude at 264.5 nm where linear relationship was obtained in the range of 2-12 μg mL-1 while Diphenhydramine Hydrochloride was determined in presence of Paracetamol and P-aminophenol using the first derivative of ratio spectra (1DD) method at 224 nm. Method B utilized chemometric techniques [Principal Component Regression (PCR) and Partial Least Squares(PLS)] which successfully applied to quantify both drugs and degradation product using the information included in the absorption spectra of appropriate solutions of the three compounds in the range of 220-340nm. Method C used HPTLC-densitometric method in which the aforementioned components were separated on silica gel plates using chloroform-ethyl acetate-ammonia solution (4:6:0.2, by volume) as a developing system. This was followed by quantitative densitometric measurement at 220 nm .Linear relationship were obtained in the concentration ranges of 0.4-1.6 μg/band , 3-12 μg /band and 0.4-1.6 μg/band for Paracetamol, Diphenhydramine Hydrochloride and P-aminophenol respectively. The proposed methods have been successfully applied to the analysis of Paracetamol and Diphenhydramine Hydrochloride in their pharmaceutical formulation without interference from other dosage form additives and the results were statistically compared with official method.

Abstract Parasitic diseases such as malaria, dengue or Schistosomiasis are a plague for millions of people mainly in underdeveloped and developing countries and often prohibit the economic development of the affected areas [1- 9]. Great efforts have been made in the past to extinct or at least control these diseases by means of medical treatment, pesticides, converting wetland etc. - but with limited success. An example of this fact is the epidemic of dengue in Brazil, more specifically in the state of Rio de Janeiro and yellow fever in the center west region of Brazil. An important problem of underdeveloped areas suffering from parasitic diseases is the poverty, which cuts off the supply with material necessary for countermeasures. In the frame of this project we intend to develop methods for pest control, which are very inexpensive and non-toxic and by this are also applicable for poor regions in the world which are infested by severe tropical diseases. The method of pest control is based on the action of photodynamic substances. In contrast to previous attempts we will use inexpensive natural substances which can easily be extracted from plants, such as chlorophylls and their derivatives. Chlorophyll does not show any toxicity in humans: chlorophyll is a colorant in the food industry (E-140 ⁄ E-141).

Abstract Protein A-Sepharose affinity chromatography is a very successful method for the purification of immunoglobulins for pharmaceutical use. However, the chromatography efficiency and lifetime of this method have to be always adjusted to specific chromatography conditions (biological source, buffers, flow rates, antibody properties, temperature, protein concentration, cleaning protocol, etc). This study sought to demonstrate improvements in the performance of an established affinity chromatography procedure employed to purify the CB.Hep-1 monoclonal antibody (mAb) used in the purification of the active pharmaceutical ingredient of a Hepatitis B vaccine. In conclusion, the relative poor mAb recovery observed in 150 mM PBS; pH 8.0/100 mM citric acid; pH 3.0 buffer system conditions was attributed to the inefficacy of the elution buffer to disrupt completely interactions between the matrix and mAb. In this regard, retention of the CB.Hep-1 mAb into the matrix was helped by the ligand coupled to the matrix and not by unspecific interactions. The 1.5M glycine-NaOH/3M NaCl; pH 9.0/200 mM glycine-HCl; pH 2.5 buffer system significantly improved the affinity chromatography recovery without affecting mAb purity, molecular homogeneity, ligand leakage and mouse DNA content in 100 purification cycles. Thus, application of 1.5M glycine-NaOH/3M NaCl; pH 9.0/200 mM glycine-HCl; pH 2.5 as buffer system allowed the reduction of the CB.Hep-1 mAb and Hepatitis B vaccine costs, respectively.

Abstract A weak electrochemiluminescence (ECL) of isoniazid in NaOH solution was observed at a platinum wire anode. When cetyltrimethylammonium bromide (CTAB) was present, the weak ECL was enhanced. The stronger ECL mechanism of isoniazid in NaOH–CTAB solution could be described as follows: isoniazid was electrochemically oxidized via one-electron and one-proton transfer to isoniazid hydrazyl radical. Then the formed radical was further chemically oxidized by dissolved oxygen to the excited state isonicotinate that subsequently emitted light. Based on the stronger ECL phenomenon of isoniazid, a flow injection ECL method for the determination of isoniazid was proposed. The ECL intensity was linear with isoniazid concentration in the range of 4.0 × 10−7 to 1.0 × 10−5 mol l−1 and the limit of detection (s/n = 3) was 1.9 × 10−7 mol l−1. The proposed method was simple and convenient operation, and has been applied to the determination of isoniazid in pharmaceutical preparations and human urine.