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The paper describes HPLC, UV spectrophotometric and non aqueous titrimetric method for the estimation of poorly water soluble protease inhibitor. Ritonavir in raw material and tablet dosage form. HPLC analysis was carried out in a C18 column using acetonitrile, methanol, and buffer in the ratio 60: 20: 20 (v/v/v) at 240 nm. For the spectrophotometric determination, methanolic solution of Ritonavir was reacted with 3-methyl benzothiazolin-2-one hydrazone (MBTH). The oxidative coupled green coloured chromogen was analysed at 633 nm. Non aqueous titration was carried out using perchloric acid as titrant and the end point was determined using crystal violet as indicator. The three methods were validated and statistically evaluated to correlate the difference between the methods for estimation of Ritonavir in pharmaceutical dosage form.

Two chromatographic methods are developed and validated to estimate Atazanavir Sulfate and Ritonavir in new fixed dosage form, that is, tablet dosage form named Synthivan. The first method is based on HPLC separation of the two drugs on the reversed phase HiQSil C18 column (5 µm, 250 × 4.6 mm) at ambient temperature using an isocratic solvent system consisting of acetonitrile and water in the ratio 52:48 (v/v). Quantification is achieved with a PDA detector at 254 nm at a flow rate of 1.5 mL/min. Linearity of concentrations is found at 60–600 µg/mL and 20–200 µg/mL for Atazanavir sulfate and ritonavir, respectively. The second method is based on HPTLC separation of the two drugs on pre-coated silica gel 60F254 aluminum plates using toluene:methanol:glacial acetic acid:ethyl acetate (7:0.5:1.5:2, v/v/v/v) as solvent system followed by densitometric measurements of their spots at 254 nm. The linearity of the concentration is found to be 30–300 and 10–100 ng/spot for Atazanavir Sulfate and Ritonavir, respect...

To study the effective therapeutic bioavailability of Atazanavir Sulfate (ATV), administered singly or in combination with Ritonavir, a cost effective and rapid method is required. In order to assess an in-depth study, it is primarily thought prudent to develop an effective analytical method for estimation of ATV in marketed dosage forms. The present work is to develop a simple and precise analytical method for in depth evaluation of therapeutic efficacy of ATV. The novelty of the method shows linearity in the concentration range of 10-100 µg/mL at two wavelengths, i.e. 254 nm and 284 nm respectively. The chromatographic system consists of HiQSil C18HS column; an isocratic mobile phase consisted of methanol and tetrahydrofuran (95:5 v/v). The developed method is validated according to ICH guidelines in capsule dosage form. Validation of the developed method shows good result in range, linearity, accuracy and precision. Student’st–test was used to correlate the two methods and applied to raw materials and capsule dosage form.

Background: Ritonavir is a protease inhibitor and mostly used as a booster for increasing the bioavailability of other protease inhibitors like Atazanavir Sulfate and Lopinavir. Aims: Quality assessment of the new dosage form of Ritonavir i.e. tablets is very essential, so two sensitive, simple and precise methods are developed for quantification of Ritonavir in bulk and tablet dosage forms. Materials and Methods: The first method is based on first order derivative method and the second is based on area under curve method. Both the methods are validated according to international conference of harmonization (ICH) guidelines. A stability study of Ritonavir is done in UV - Visible Spectrophotometer under different stress conditions recommended by ICH guidelines. Results: The absorption maximum is found to be 239nm in methanol. The absorption maximum in first method is chosen at 253.2nm, and the linearity is found between 4 - 20 ΅g/ml with coefficient of correlation value 0.9981. In the second method, the range for area under curve selected is 237 - 242nm. The linearity is found between 4 -20 ΅g/ml with coefficient of correlation value 0.9992. Conclusion: The developed methods are validated and found to be simple, rapid, precise and cost-effective. The degradation study in tablet dosage form can be used as a stability indicating assay method.

1used in the treatment of human immunodeficiency virus (HIV) Type II infection. ATV is re ported as poorly water soluble and a known substrate for both hepatic metabolizing enzyme Cytochrome 450 (CYP3A) and intestinal drug efflux pump, P-glycoprotein (Pgp) so have low oral bioavailability. 2 So co-administration of small dose of Ritonavir (RTV) is recommended as booster. This new drug is official in IP - 2010, but not included in BP or USP. The reported analytical methods for the determination of ATV are based on high performance liquid chromatography (HPLC) 3-12 in biological samples like blood plasma, biological cells, cerebrospinal fluid (CSF) and blood serum. Stress degradation studies were reported analysed by HPLC and ultraviolet spectrophotometry. 13, 14 The present work was aimed to develop a visible spectrophotometric method, which is simple, sensitive, accurate and cost effective to evaluate the quality of the bulk and pharmaceutical formulations. The novelties of the developed methods are that the reagents used in both the methods are easily available and the mechanisms of reactions of the reagents are already well established. The reactions involved with these reagents are simple, rapid and sensitive. Spectrophotometric methods involve simple instrumentation which is cost effective as compared to other instrumental techniques. The present method involves the determination of ATV, which is a second line drug for treatment of type II HIV infection. Still now, the 2 nd line drugs are available at higher price, than the 1 st line drugs. The high