An emerging way of estimation of Olmesartan medoxomil &

Hydrochlorothiazide in Bulk & Combined tablet dosage form by Absorbance

Correction Method By Priyanka Bose

M. PhramDr. H. S. Gour University, Sagar, MP

INTRODUCTION• Spectrophotometry is generally preferred by small-scale industries as the cost of

equipment is less and the maintenance problems are less.• The method of analysis is based on measuring the absorption of a monochromatic light

by colorless compound in the ultraviolet region of spectrum (200 – 400 nm).• The photometric method of analysis are based on the Beer’s-Lambert law i.e, I α 10 –cl

I0

where., I = transmitted light I0 = initially fallen light

c = concentration of the solute in the solvent which causes absorption of light. L = path length Log 10 (I/ I0) = € C L

So the absorbance of a solution is directly proportional to the concentration (C) of the analyte as the pathway (L) remains constant.

• The combined formulation (OLM & HCT) has no standard protocol for the estimation or Q.C. testing method in any compendia and official pharmacopeia. So it has been chosen as the model drug for the method development.

OBJECTIVE• The objective of this work is to develop and validate a simple and cost effective analytical method by using UV-VIS spectrophotometry for the estimation of Olmesartan (I) and Hydrochlorothiazide (II) in bulk and pharmaceutical combined dosage forms as per I.C.H (International Conference on Harmonization) Guidelines.

III

DRUG PROFILE• Olmesartan medoxomil, a prodrug, is hydrolyzed to olmesartan during absorption from the gastrointestinal tract. It is a selective angiotensin-II receptor antagonist. It is a white to light yellowish-white powder or crystalline powder which is ester prodrug, derivative of biphenyl tetrazole category and angiotensin type 1 receptor blocker used in treatment of high blood pressure which is rapidly hydrolyzed to olmesartan in G.I.T. to ensure better bioavailability by oral route (26%).

• Hydrochlorthiazide is a thiazide diuretic often considered the prototypical member of this class. It reduces the reabsorption of electrolytes from the renal tubules (DCT). This results in increased excretion of water and electrolytes, including sodium, potassium, chloride, and magnesium. It has been used in the treatment of several disorders including edema, hypertension, diabetes insipidus, and hypoparathyroidism.

LITERATURE RIVIEWThe literature survey reveals that few analytical methods such as u v [1-4], HPLC [5-7], and few other methods are available at present. To our knowledge no study related to absorbance correction method of estimation for the drug combination has been reported in literature in precise manner. Therefore there was a challenge to develop an accurate précised validated U.V method for the drug combination. to develop UV spectro-photometric method for the simultaneous estimation of OLM and HCT. The present study was involved in a research effort aimed at developing and validating a simple, specific, accurate, economical, less time consuming and precise UV spectro-photometric method for the combined pharmaceutical dosage form.

MATERIALS REQUIRED CHEMICALS- OLMESARTAN MEDOXOMIL (BULK) HYDROCHLOROTHIAZIDE (BULK) OLMESAR H 20 (MARKETED FORMULATION) EQUIPMENTS/INSTRUMENTS- UV-VISIBLE SPECTROPHOTOMETER ELECTRONIC BALANCE (1mg sensitivity) SONICATOR APPARATUS- 10ml VOLUMETRIC FLASKS 10ml & 1ml PIPPETTES Whatmann filter papers Funnels Scroller

PLAN OF WORK• UV Method Development (Absorbance Correction Method)

– Solubility test– Selection of λmax

– Preparation of Calibration Curve

• UV Method Validation– Linearity– Precision (intra & inter)– Accuracy – Specificity– Ruggedness– Robustness – Repeatability– Limit Of Detection (LOD)– Limit Of Quantification (LOQ)

MethodologyProcess-• The solubility study by different solvents has been done.

• As the drug is freely soluble in methanol and shows good absorbance so methanol is selected as the solvent.• UV- Visible double beam spectrophotometer ( shimadzu uv-1800) is employed with spectral band width of 1 nm with automatic correction with a pair of 1 cm matched quartz cell.• Different concentration of OLM ( 0.1- 3 µg/ml ) and HCT (0.1-1.4 µg/ml) and the synthetic mixture ( taking talc as excipient ) is scanned between 200 to 400nm as 255.6 nm and 270 nm is the λmax of respective drugs.• Absorbance are measure and absorptivity is determined and the calibration curve is also determined of r2 = 0.998. and the marketed formulation olmesar H 20 is being analysed taking the calibration curve in consideration and the formulation is in the ratio of OLM : HCT, in 10 : 6.25

CALIBRATION GRAPHS

GRAPHICAL REPRESENTATION

METHOD OF VALIDATIONLinearity Precision Accuracy

Specificity

RuggednessRobustnessLimit of

Detection (L.O.D)

Limit of Quantification

Repeatability

Assay of Marketed Formulation

Validated method

SUMMARY OF VALIDATIONSl no Parameters Drug

OLM HCT

1 Precision indicated by % RSD 1.038 0.623

2 Accuracy indicated by % recovery 99.61% 99.0%

3 Specificity indicated by % recovery 99.93% 98.843%

4 LOD / Limit of detection 0.151 0.039

5 LOQ / Limit of quantification 0.459 0.121

6 Range 1-20 ppm 1-15 ppm

7 Linear regression equation y = 0.0663x + 0.0525 y = 0.0458x + 0.0509

8 Robustness indicated by % RSD 0.316 0.205

9 Assay indicated by % recovery 99.558% 97.342%

10 Linearity indicated by correlation coefficient

0.997 0.998

RESULTS & DISCUSSION• The developed method was found to be precise as the %RSD (Relative

Standard Deviation) values for intra-day and inter-day were found to be less than 2%.

• Good recoveries (99.97% to 101.4%) of the drug were obtained at each added concentration, indicating that the method was accurate.

• The method was also found to be specific indicated by the % recoveries ranging from 98.2% to 101.2%.

• The LOD and LOQ were found to be in sub-microgram level indicating the sensitivity of the method here 0.1 µg/ml concentrated solution is being analysed for that.

• The method was also found to be robust and rugged as indicated by the %RSD values which are less than 2%.

• The results of Assay show that the amount of drug was in good agreement with the label claim of the formulation (Olmesar H 20) as indicated by % recovery (101.8%).

CONCLUSION• This method is considered simple, reliable, and selective providing satisfactory

accuracy, precision with lower limits of detection, more specific quantification and sensitivity.

• The good recoveries were obtained in all cases, and the reliable agreement with the reported procedure proved that the proposed method could be applied efficiently for the determination of OLM and HCT in oral dosage form with satisfactory precision.

• Moreover, the shorter duration of analysis of OLM and HCT marks the reported method suitable for routine analysis in pharmaceutical dosage forms.

Sl no. Parameter Acceptable limit Remark

1 Accuracy % Recovery 100 ± 2 % Passed2 Specificity % Recovery 100 ± 2 % Passed3 Precision RSD < 2 Passed4 Linearity r2 ≤ 0.99 Passed5 Robustness RSD < 2 Passed6 Assay % Recovery 100 ± 2 % Passed

REFERENCE1. A.T. HEMKE, M.V. BHURE, K.S. CHOUHAN,K.R. GUPTA and S.G. WADODKAR UV

Spectrophotometric Determination of Hydrochlorothiazide and Olmesartan Medoxomil in Pharmaceutical Formulation

2. T. Hemke, M. V. Bhure, K. S. Chouhan, K. R. Gupta, and S. G. Wadodkar, UV Spectrophotometric Determination of Hydrochlorothiazide and Olmesartan Medoxomil in Pharmaceutical Formulation

3. Derivative and Q analysis spectrophotometric methods for estimation of hyroclorthiazide and olmesartan medoxomil in tablets by K.P. Bhusari, P.B. Khedekar, Seema Dhole, VS Banode.

4. Spectrophotometric estimation of olmesartan midoxomil and hydrochlorthiazide in tablet by A P Rode and P. D. Bari.

5. Simultaneous HPLC Analysis of Olmesartan and Hydrochlorothiazide in Combined Tablets and in vitro Dissolution Studies by O. Sagirli,  A. Önal,  S. E. Toker, D. Şensoy

6. Ratio Spectra Derivative and Zero-Crossing Difference Spectrophotometric Determination of Olmesartan Medoxomil and Hydrochlorothiazide in Combined Pharmaceutical Dosage Form, Ambadas R. Rote  and Pankaj D. Bari

7. DEVELOPMENT AND VALIDATION OF A REVERSED PHASE HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF OLMESARTAN AND HYDROCHLOROTHIAZIDE IN COMBINED TABLET DOSAGE FORM B. Raja and A. Lakshmana Rao

8. DEVELOPMENT AND VALIDATION OF A REVERSED PHASE HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF OLMESARTAN MEDOXOMIL AND HYDROCHLOROTHIAZIDE IN COMBINED TABLET DOSAGE FORM Moynul Hasan, Abdullah Al Masud and Jamiuddin Ahmed

9. ICH (1996) Q2B Validation of Analytical Procedures – Methodology, Consensus Guidelines, ICH Harmonized Tripartite Guideline