Dipak Patil

Lurasidone is an atypical antipsychotic approved by FDA for the treatment of schizophrenic disorder and depressive episodes linked through bipolar I disorder in adults when used exclusively or in combination with lithium or valproate. Lurasidone is a benzisothiazole antipsychotic, an antagonist at D2, 5-HT2Aand 5-HT7 receptors and a partial agonist at 5-HT1A receptors. As with other antipsychotics, the exact mechanism of action of lurasidone is unknown, although its effects in schizophrenia are supposed to be related to D2 and 5-HT2A receptor antagonism. This work includes published analytical methods so far reported in the literature, for estimation of lurasidone in biological samples and pharmaceutical formulations. Techniques like UV-Visible Spectrophotometry, high-performance liquid-chromatography (HPLC), high-performance thin-layer chromatography (HPTLC), and Liquid chromatography-mass spectroscopy (LC-MS) with ESI have been used for analysis, from which it can be witnessed tha...

Objective: Two simple, accurate, precise, reproducible and an economical spectrophotometric methods were developed for the simultaneous estimation of ibuprofen and famotidine in pharmaceutical bulk and synthetic mixture. Methods: The first method was developed on the basis of Q-absorbance ratio method (method I) for analysis of both the drugs. Wavelengths selected for analysis in Q-absorbance ratio method were 263 nm (λmax of ibuprofen) and 273.80 nm (iso-absorptive wavelength) in 0.1N NaOH. The second method was based on derivative spectrophotometric method (method II) involving the determination of both the drugs at their respective zero crossing point. The determinations were made at 252.8 nm (zero crossing point of famotidine) and 304 nm (zero crossing point of ibuprofen) in 0.1N NaOH. Results: Both the method obeys Beer-Lambert's law in the concentration range of 150-750 μg/ml for ibuprofen and 5-25 μg/ml for famotidine. The assay result of synthetic mixture was found to be...

The Maillard reaction between hydroxyurea (a primary amine-containing drug) and lactose (used as an excipient) was explored. The adduct of these compounds was synthesized by heating hydroxyurea with lactose monohydrate at 60 °C in borate buffer (pH 9.2) for 12 h. Synthesis of the adduct was confirmed using UV-visible spectroscopy and Fourier transform infrared, differential scanning calorimetry, high-pressure liquid chromatography, and liquid chromatography-mass spectrometry studies. An in silico investigation of how the adduct formation affected the interactions of hydroxyurea with its biological target oxyhemoglobin, to which it binds to generate nitric oxide and regulates fetal hemoglobin synthesis, was carried out. The in silico evaluations were complemented by an in vitro assay of the anti-sickling activity. Co-incubation of hydroxyurea with deoxygenated blood samples reduced the percentage of sickled cells from 38% to 12 ± 1.6%, whereas the percentage of sickled cells in sampl...

ABSTRACT A simple, sensitive and reproducible spectrophotometric method is developed for determining the pregabalin (PGB) content in bulk and in capsule dosage form using an experimental design approach. The proposed method is based on the condensation reaction of PGB (primary amine) with p-dimethylaminobenzaldehyde (PDAB) in an acidic medium to form a PGB–PDAB complex. The PGB–PDAB complex shows maximum absorption at 395.80 nm. The proposed method is validated according to the ICH Q2 (R1) guidelines for validation of analytical methods. The percentage purity of PGB in capsule dosage form as determined using the proposed method is 100.05 ± 1.48 whereas the corresponding value by the official method (Indian Pharmacopoeia, 2010) is 100.46 ± 0.41. The t-value and F-value are calculated for statistical comparison and are found to be 0.60 and 0.08, respectively. The proposed method may recommend for routine quality control analysis of PGB in its pharmaceutical dosage form.

ABSTRACT A precise, accurate, sensitive and robust RP-HPLC method was developed for cefepime hydrochloride and tazobactam sodium in bulk and pharmaceutical formulation. Chromatographic separation was achieved on PrincetonSPHER-100 C-18 column (250 mm × 4.6 mm i.d., 5 µm) at ambient temperature. A binary mobile phase consisting of 25 mM potassium dihydrogen phosphate buffer, pH 6.2 and acetonitrile (94 : 6, v/v) was delivered through a column at a flow rate of 1 mL/min. Measurement was performed at a wavelength 210 nm. The method was linear over the concentration range of 4–24 µg/mL () for cefepime and 0.5–3.0 µg/mL () for tazobactam. The percentage content found for cefepime was 101.12 ± 0.49 and for tazobactam was 101.33 ± 1.17 in the pharmaceutical formulation. The method was validated for linearity, precision, accuracy, sensitivity and robustness as per ICH Q2 (R1) guideline.

Lactose is used as an excipient in solid dosage forms of nebivolol. Ultraviolet spectroscopy, Fourier-transform infrared spectroscopy and differential scanning calorimetry were used to study the interaction between nebivolol and lactose. The formation of a Maillard product was noted in aqueous mixtures of nebivolol and lactose heated at 60°C at unbuffered and buffered alkaline pH. A similar Maillard adduct formation was evident within 15 days in a dry physical mixture of nebivolol and lactose maintained at 40°C and 75% relative humidity in the dark. High-performance liquid chromatography and liquid chromatography-mass spectrometry analyses of the reaction mixtures confirmed the formation of a nebivolol-lactose adduct. The effects of intravenously administered nebivolol and the nebivolol-lactose adduct on the blood pressure and heart rate of anesthetized normotensive rats were investigated. The bradycardic effect of the adduct was significantly less than that of nebivolol. The present investigation reveals an incompatibility between nebivolol and lactose, leading to the loss of the pharmacological activity of nebivolol. Hence, the use of lactose as an excipient in dosage forms of nebivolol, a secondary amine, needs reconsideration.