FORM - 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
PROVISIONAL SPECIFICATIONS
"Improved Process for Manufacturing Higher Strength Hard Capsules from Water-Soluble Cellulose Derivative Devoid Of Gelling Agents"
Scitech Centre
An Indian Company Registered under the provisions of Companies Act, 1956.
having address at 7,
Prabhat Nagar
Jogeshwari (West)
Mumbai-400 102
The following specification describes the nature of the invention

FIELD OF THE INVENTION
Present invention relates to an improved process for manufacturing of hard capsules from water-soluble cellulose derivatives. More particularly present invention related to an improved process for manufacturing of hard capsules from water-soluble cellulose derivatives of low viscosity grade without use of gelling agents / gelling aids and to achieve higher strength.
BACKGROUND OF THE INVENTION
Hard capsules made from water-soluble cellulose derivatives such as HPMC are disclosed in EP 1044682 entitled, "PROCESS FOR PRODUCING HARD CAPSULE". The said patent disclosed the hard capsules manufacturing process comprising the steps of dispersing water cellulose derivatives in hot water followed by cooling the dispersion to effect the dissolution of the water soluble cellulose derivatives in the water, followed by adding and dissolving the gelling agent in the water soluble cellulose derivatives solution to give a capsule preparing solution, further dipping capsule-forming pin into the solution at a predetermined temperature, further withdrawing the pin and inducing gelatin of the capsule preparing solution adhering to the pin.
The process for the preparation of hard capsules as disclosed in the patent no EP 1044682 has also disclosed the addition of gelling agent in order to induce gelation of the capsule preparing solution adhering to the pin.
It is observed that the hard hell capsule produced by the above process has very poor mechanical strength due to molecular weight of the polymer. Therefore the inventors of the present invention proposed an improved process in order to overcome the drawbacks and disadvantage of the prior arts.
BRIEF DESCRIPTION OF THE INVENTION
The object of the present invention aims at developing an improved process for manufacturing of hard capsules without addition of gelling agent / gelling aids.

The present invention provides an improved process for manufacturing of hard capsules from water-soluble cellulose derivatives of low viscosity grade comprising of the steps of dispersing the water-soluble cellulose derivatives of 2910 chemistry of viscosity grade between 3 cps to 6 cps in water above 80°C temperature. Followed by separately dispersing the water-soluble cellulose derivative of high viscosity grade of 2208 and / or 2910 chemistry of viscosity between 15,000 to 1,00,000 (60 SH - 10000, 90 SH -15,000, 90 SH -100,000 of Shinetsu) in water of temperature above 80°C followed by soaking respective dispersions at high temperature for proper hydration for 6 - 15 hours under constant stirring. Followed by mixing both the solutions in the proportion of 10:1 and bring the temperature between 58°C to 65°C in order to make the solution ready for dipping.
Further dipping the capsules-forming mould & picking up the solution around mould. Followed by moulds to rotate in the temperature of 20°C - 25°C and relative humidity between 30 - 40 %. This causes the temperature of the wet mass picked up to lower below 20°C. The lower temperature causes the viscosity to rise substantially and allowing the mass to set. The capsules are then subsequently dried and cut to required size & shape. The combined strength of the shell also imposes to more than 25%.
Improvement lies in adding water-soluble cellulose derivative of high viscosity grade and allowing the water-soluble cellulose derivative of high viscosity grade to solublise on pin to give rise in viscosity. This eliminates the need of addition of gelling agent / gelling aid. Higher molecular weight is also an important factor for imparting the strength of shell increase by 25 %.