How to save pdf into database?

string attachment = "attachment; filename=" + "abc" + ".pdf";
                Response.ClearContent();
                Response.AddHeader("content-disposition", attachment);
                Response.ContentType = "application/pdf";
                StringWriter s_tw = new StringWriter();
                HtmlTextWriter h_textw = new HtmlTextWriter(s_tw);
                h_textw.AddStyleAttribute("font-size", "7pt");
                h_textw.AddStyleAttribute("color", "Black");
                Panel1.RenderControl(h_textw);//Name of the Panel
                Document doc = new Document();
                doc = new Document(PageSize.A4, 5, 5, 15, 5);
                FontFactory.GetFont("Times New Roman", 14);
                PdfWriter.GetInstance(doc, Response.OutputStream);
                doc.Open();
                StringReader s_tr = new StringReader(s_tw.ToString());
                HTMLWorker html_worker = new HTMLWorker(doc);
                html_worker.Parse(s_tr);
                doc.Close();
                Response.Write(doc);