Conceptual view of Drug Design & Dosage forms in Ancient Indian Pharmaceutics: An Everlasting Outlook.
ABSTRACT Abstract: - The Indian system of medicine, being a comprehensive sort of knowledge indeed had Pharmaceutical branch inclusive within it on contrary to the modern system of medicine. Though food is meant to be medicine primarily even the drug designing by the seers was to make it more acceptable to the patients. Because the preparation of medicine was not just making it but the planning, processing & presenting1.
Each & every dosage form, ingredients naturally procured undergoes series of process & screening to make it a target oriented bio-available drug. A detailed pharmacology & toxicological studies were carried out even during that time to produce one final dosage form. Accordingly even animals were used for such experiments. 2
The technology involved from the selection of a raw drug until its final structure after lot of permutations & combinations was to make the drug dosage form a safe, effective & a stable entity. Because the Bheshaja or the ayurvedic medicament was not only to meant for the treatment or curing the disease but also by making it appealing to both body & mind, bring back to the state of equilibrium & so to lead a healthy life3.
Not all the dosage forms were meant for preservation for longer periods instead for the potent action at the earliest which otherwise would be ineffectual. Rasashastra & Bhaishajya Kalpana, one of unique branches in Ayurveda is a comprehensive knowledge of Ayurvedic Pharmaceutics.
The drug dosage forms mentioned in classics like swarasa (juice extract), Kalka (pastes), churna (powders), Kashaya (decoctions), Hima (a cold infusion), Phanta (a hot infusion), Ksheerapaka (medicated milk), Arka (liquid distillate), Ghanasatwa (the solid extract), Guda & Khanda kalpana (jaggery sugar based solid preparations), Phanitha (Highly concentrated juice), Avaleha (linctus), Vati (solid dosage forms by adding powders & liquids), Guti (Smaller sized solid dosag form), modaka (bolus sort of dosage), Pindi (pea sized solid dosage), Varti (suppositories), Anjana (microfine paste only for eyes), Masi (carbon form of a drug), Lavana (granule salt form), Ayaskriti (Metallo-mineral liquid dosage), Satva (starchy extract), Ksara (alkaline powders), Dhupana (fumigative powders), Dravaka (acidic/alkaline distillates), Ghrutha (medicated ghee), taila (medicated oil), Asava & arishta (fermented liquids), Lepa (creams), Malahara (ointments), upanaha (poultices) etc. are found in Bhaishajya kalpana.
The drug dosage forms in Rasashastra are Bhasmas (calcined/incineratd forms of metals& minerals), Parpati (crispy thin wafers), Pottalis (Kupi pakwa rasayanas as Sindooras(Sulphide/oxide forms of Hg), Rasas (powder/vati/guti forms), Manduras (Iron preparations), Pisti (Calcium mixtures), in the form of powders or gutis , Satva (metallic extracts), Dhruti (liquified metals), Pushpa ( karpoora(non-sulphuric mercurial forms), Bandhas (Mixture of Hg with herbs & minerals), Suchikabharana rasa (injectables).
Though major part of medicaments is in the forms of vatis/gutis having taken the form of tablets & churnas filled in capsules. The swarasas/rasakriyas having replaced by syrups are only in vogue .The dynamics (what drug does to the body) & kinetics (what body does to the drug) of the conventional genuine drug dosage forms are still precise with its distinctive properties. The principle behind ancient drug design & dosage forms whether it was a single drug or a combination (samyoga) was:-
• Nature of the drug
• Disintegraion & dissolution
• Onset & Duration of action
• Synergism & Antagonism
• Easy ADME
• Drug affinity
• Magical bullet technique or Prabhava.
This presentation is one such attempt to show the everlasting intellectual skills of the ancient seers who examined the biophysics & biochemical concepts of molecular interactions between ligands & their receptors & resulting applications for rational drug design.