C. Dinesh Kumar

Oral Antidiabetic Activity of Annona squamosa Leaf Alcohol Extract in NIDDM Rats

The leaf alcohol extract of the plant Annona squamosa was investigated for its antidiabetic activity. Type 2 diabetes mellitus was induced with standardised doses of streptozotocin and nicotinamide. Graded doses of the leaf alcohol extract suspended in gum acacia were administered to normal and experimental diabetic rats for 12 days. Fasting plasma glucose levels, serum insulin levels, serum lipid profiles and changes in body weight were evaluated in normal rats while liver glycogen levels and pancreatic TBARS levels were evaluated additionally in diabetic rats. The diabetic groups treated with the leaf alcohol extract were compared with standard glibenclamide. The findings showed the significant antidiabetic potential of the extract in ameliorating the diabetic conditions in diabetic rats. No significant effects were found in the normal rats.

Simultaneous UV spectrophotometric estimation of ambroxol hydrochloride and levocetirizine dihydrochloride

A novel, simple, sensitive and rapid spectrophotometric method has been developed for simultaneous estimation of ambroxol hydrochloride and levocetirizine dihydrochloride. The method involved solving simultaneous equations based on measurement of absorbance at two wavelengths 242 nm and 231 nm, the γ max of ambroxol hydrochloride and levocetirizine dihydrochloride, respectively. Beers law was obeyed in the concentration range 10–50 μg/ml and 8–24 μg/ml for ambroxol hydrochloride and levocetirizine dihydrochloride respectively. Results of the method were validated statistically and by recovery studies.

Simultaneous Estimation of Esomeprazole and Domperidone by UV Spectrophotometric Method.

A novel, simple, sensitive and rapid spectrophotometric method has been developed for simultaneous estimation of esomeprazole and domperidone. The method involved solving simultaneous equations based on measurement of absorbance at two wavelengths, 301 nm and 284 nm, λ max of esomeprazole and domperidone respectively. Beers law was obeyed in the concentration range of 5-20 μg/ml and 8-30 μg/ml for esomeprazole and domperidone respectively. The method was found to be precise, accurate, and specific. The proposed method was successfully applied to estimation of esomeprazole and domperidone in combined solid dosage form.

Studies of disintegrant properties of seed mucilage of Ocimum gratissimum

Dispersible tablets of Metformin Hydrochloride were prepared using Ocimum gratissimum mucilage powder and Ocimum gratissimum seed powder as disintegrants. Specifications for herbal raw materials and finished products were set according to the Committee for Proprietary Medicinal Products. Several formulations were prepared and evaluated for physical parameters such as thickness, hardness, friability, weight variation, drug content, and disintegration time and drug dissolution. The formulations were prepared with different proportions of Ocimum gratissimum mucilage powder and Ocimum gratissimum seed powder. The formulated tablets had good appearance and better drug release properties as compared to the marketed conventional tablets. The study revealed that Ocimum gratissimum mucilage powder and Ocimum gratissimum seed powder were effective as disintegrants in low concentrations (5%). The study further revealed a poor relation between the swelling index and disintegrating efficiency. Mucilage extracted from Ocimum gratissimum seeds was subjected to toxicity studies for its safety and preformulation studies for its suitability as a disintegrating agent. The mucilage extracted is devoid of toxicity. Studies indicated that the extracted mucilage is a good pharmaceutical adjuvant, specifically a disintegrating agent.

Determination of ebastine in pharmaceutical formulations by HPLC.

A simple, precise and rapid RP-HPLC method was developed for the determination of ebastine in pharmaceutical formulations. The method was carried out on a Phenomenex RP-C18 column using a mixture of methanol and water (90:10) and detection was done at 262 nm. The linearity range was 5-100 μg/ml. The intra-day and inter-day precision were in the range of 0.22% to 0.49% and 0.24% to 0.73%, respectively.

Determination of racecadotril by HPLC in capsules

A simple, precise and rapid RP-HPLC method was developed for the determination of racecadotril in a pharmaceutical formulation using gemfibrozil as internal standard. Ratio of the peak area of analyte to internal standard was used for quantification. The chromatographic separation was carried out by using a Reverse Phase C18 column (BDS-Hypersil). The mobile phase consisting of a mixture of 20 mM phosphate buffer (pH 3.5) and acetonitrile in the ratio of (40:60) with detection at 230 nm at a flow rate of 1 ml/min was employed. The method was statistically validated for linearity, accuracy and precision. The elution time was 6.9 min for racecadotril and 9.8 min for gemfibrozil. The simplicity and accuracy of the proposed method ensures its use in routine quality control analysis of pharmaceutical formulations.

Spectrofluorimetric method for determination of duloxetine hydrochloride in bulk and pharmaceutical dosage forms

A simple accurate, sensitive and reproducible spectrofluorimetric method was developed for the analysis of duloxetine hydrochloride in pure and pharmaceutical dosage form. Duloxetine hydrochloride showed strong native fluorescence in 0.05 M acetic acid having excitation at 225 nm and emission at 340 nm. Effect of different solvents were thoroughly investigated. The calibration graph was linear in the range from 0.020 to 0.400 μg/ml. The proposed method was statistically validated and successfully applied for analysis of capsule dosage forms. The limit of detection and limit of quantification were found to be 0.003 μg/ml and 0.010 μg/ml, respectively. The percentage recovery was found to be in the range of 98.71% to 99.17%.