Formulation And Evaluation of Oral Disintegrating Tablet of Doxylamine Succinate

Tablet: Tablet is a solid dosage forms each containing a unit dose of one or more medicaments with or without suitable excipients. Tablets may be swallowed whole or being chewed. Some are dissolved or dispersed in water before administration. Some are put in oral cavity, where the active ingredient is liberated at a predetermined rate. Implants  or passeries may also be presented in form of tablet. Tablet may vary in shape and differ greatly in size and weight depending on the amount  of  medicinal  substance  and  the intended mode of administration. Tablets are usually solid, right circular cylinders, the end surfaces of which  are flat  or convex and the edges of which may be beveled. They may exist in other shapes like triangular, rectangular, etc. They may have lines or break- marks and may bear a symbol or other markings. They are sufficiently hard to withstand handling without crumbling or breaking1.  

Advantages of the Tablet dosages form

• Tablets are convenient to use and are an elegant dosage form.
• Objectionable odour and bitter taste can be masked by coating technique. .
• Tablets are generally inexpensive dosage form.
• Suitable for large scale production
• Greatest chemical and microbial stability over all oral dosage form.     

2. Material and Method:

Table No. 1 List of Material

UV Spectroscopic study

Preparation of standard stock solution in distilled water

The standard solution containing the drug was  prepared by dissolving 10 mg of DOXYLAMINE SUCCINATE was transferred into a 10 ml volumetric flask to which distilled water was added up to mark to produce 1000µg/ml53.

Preparation of stock solution in phosphate buffer (pH6.8)

The standard solution containing the drug was  prepared by dissolving 10 mg of DOXYLAMINE SUCCINATE was transferred into a 10 ml volumetric flask to which phosphate buffer pH 6.8 was added up to the mark to produce 1000 µg/ml53.

Determination of λ max in distilled water and phosphate buffer (pH6.8)

By appropriate dilution of standard drug solution with distilled water and phosphate buffer, a solution containing10μg/ml and 5µg/ml of DOXYLAMINE SUCCINATE was scanned within the range of 400 – 200 nm against distilled water and phosphate buffer pH 6.8 for the determination of maximum absorption for the drug in both the solvent.

Preparation of calibration curve

From the above stock solution,1ml (1000µg/ml)of solution was transferred into 10 ml of volumetric flask to prepare 100 µg/ml working standard, from which aliquots of 0.2, 0.4, 0.6, 0.8 and 1.0 ml were transferred and volume was make up with distilled water into 10 ml volumetric flask to obtain the final concentration range of 2, 4, 6, 8 and 10 µg / ml. The solution was separately analyzed. Same  procedure was followed for phosphate buffer  pH 6.854.

Drug characterization

Determination of melting point

The capillary tube was taken and its one end was sealed by heating it. The sealed capillary tube was filled with DOXYLAMINE SUCCINATE up to 1cm high. The tube was placed in melting point apparatus with a thermometer. The change in the sample was noted  on  a gradual increase in the temperature. The temperature at which the drug started melting and gets completely melted was noted55.

Solubility determination

The shake – flask method is  used to determine the solubility  of  DOXYLAMINE SUCCINATE in distilled water and phosphate buffer (pH6.8).The sample is which is in a Stopper flask or vial. The vials were sealed and stirred for 10 minutes. Then they were kept on an orbital flask shaker at 37oC for 24 hours. After solubilization of the drug, an extra amount of the drug was added to the vial. This process is repeated until saturation solubility of drugs indicated by the presence of an undissolved drug. Then the mixture is kept aside for 24 hours and centrifuged at 3000 rpm for 15 minutes. The supernatant was separated and diluted with the respective solvent. The concentration of the drug was analyzed at 260 nm and 264 nm using a UV- visible spectrophotometer55.

Drug – Excipients compatibility study: Preparation of TLC plate: Firstly silica gel-G slurry prepared by mixing silica gel- G with distilled water in mortar pestle and triturated continuously to make uniform slurry. The slurry was poured uniformly  on glass slide and allowed to dry plate in hot air oven at 120 o C. Preparation of sample: The blend of drug with excipients in the ratio of 1:1was dissolved in  water. A capillary tube was used to spot the sample on TLC plates. The diameter of each spot was limited to 0.3 cm. The compounds were spotted at 1 cm above from the bottom of the  plate.  Development  of  the  solvent system: The solvent system was prepared using ethanol: water (1:1) was used as mobile phase. The 100ml of small beaker was used and the solvent system was poured in it. The glass beaker was lined with filter paper for prostration with the solvent system for15-30 minutes56.

Stationary Phase – Precoated silica gel – G Mobile Phase–ethanol: water (1:1)

Development of thin layer plate: The previously spotted plates kept in mobile phase. Plates were developed in an ascending manner. When the solvent reached to the mark the plate was removed and the wet plates were dried.

Detection of spot: The iodine chamber was prepared and TLC plate was placed in a chamber. Therefore the plate was removed from chamber and spots was observed and calculate Rf value.   

Table. 2 Selection of excipients

The two factor three level design (32) was used for the formulation and optimization of orodispersible tablet of DOXILAMINE SUCCINATE and experimental trials are performed at all 9 possible formulations. In which the amount of sodium starch glycolate and cropovidone were selected as independent variables at three different level : low (-), medium (0), and high (+1) levels. The drug release and disintegration time used as a dependent variable (response).

Table No 3 formulation of oral disintegrating tablet of Doxilamine succinate