DEVELOPMENT AND CHARACTERIZATION OF GASTRORETENTIVE DRUG DELIVERY SYSTEM FOR RITONAVIR TABLETS USING NATURAL POLYMERS

Objective: The present study involves preparation and evaluation of floating tablets of ritonavir for improving the drug bioavailability by prolongation of gastric residence time.Ritonavir is an antiretroviral agent used in treatment of HIV and viral diseases has been taken as a model drug in the present investigation because of its low biological half life (3-5h). Moreover it is primarily absorbed from stomach. Materials and Methods: Ritonavir floating tablets were prepared by the dry granulation technique, using guar gum and xanthan gum as polymers, sodium bicarbonate as effervescent agent, PVP as binding agent, Di calcium phosphate as diluents, Crospovidone as swelling agent and magnesium stearate as lubricant. The prepared tablets were evaluated for various physico-chemical parameters. Results: Drug-excipient interaction studies were conducted by FTIR and DSC. The results suggested that there was no incompatibility between the drug and polymers. The prepared tablets were evaluated for their physical characteristics. All the parameters were within the pharmacopoeial limits.  Further, tablets were also studied for their floating properties and in vitro drug release characteristics. The tablets exhibited controlled and prolonged drug release profiles. The developed formulation was found to be stable. Conclusion: The developed floating tablets of ritonavir exhibit prolonged release upto 12 h, and thus may improve bioavailability and minimize fluctuations in plasma drug concentrations.Â

Development of Tizanidine HCl transdermal patches: In-vitro and Ex-vivo characterization

The purpose of this work was to design and evaluate matrix type transdermal patches of Tizanidine hydrochloride using Hypromellose (HPMC E15) as polymer, dibutyl phthalate as plasticizer and citral as permeation enhancer. The DSC and FTIR results showed the compatibility of the excipients with the drug. These transdermal drug delivery systems were characterized for their thickness, folding endurance, content uniformity, tensile strength and in-vitro release studies of the drug from the polymeric matrix. In-vitro release studies and ex-vivo permeation were carried out with modified Franz diffusion cell using pH 5.8 & pH 7.4 phosphate buffers as receptor medium and it showed controlled release of drug. The results suggest that the formulation of TIZ may be useful in the development of a therapeutic system to deliver TIZ across the skin for a prolonged period, i.e. 24 hr. Keywords: Tizanidine Hydrochloride, Transdermal patch, HPMC E15, in-vitro & ex-vivo

Formulation and evaluation of commonly used natural hair colorants

45-48Loss of colour in hair is due to varied reasons like genetic influence, effect of environmental factors, use of alcoholic preparations, etc. Though the permanent synthetic hair dyes are available in different colour ranges and retain natural lustre, they have the chief disadvantage of producing hypersensitive reactions in some individuals. In the present investigation various combinations of powdered leaves, fruits and flowers of dye yielding and hair care plants like Henna, Indigo, Bhringraj, Amla, Catechu and Centella were evaluated for their colouring and sensitivity reactions. Henna and Indigo formulation was found to be suitable natural colorant